Sunday, March 24, 2019

Feeling Alone Among 317 Million Others: Twitter is used to both seek and provide support regarding loneliness; weekend and night-time disclosures are associated with the angriest language

Feeling Alone Among 317 Million Others: Disclosures of Loneliness on Twitter. JamieMahoney et al. Computers in Human Behavior, MAr 24 2019.
https://doi.org/10.1016/j.chb.2019.03.024

Highlights
•    Twitter is used to both seek and provide support regarding loneliness.
•    Language in these disclosures differ when related to the day and time of disclosure.
•    Weekend and night-time disclosures are associated with the angriest language.
•    A range of disclosures suggest that user behaviour may develop over time.

Abstract: Increasing numbers of individuals describe themselves as feeling lonely, regardless of age, gender or geographic location. This article investigates how social media users self-disclose feelings of loneliness, and how they seek and provide support to each other. Motivated by related studies in this area, a dataset of 22,477 Twitter posts sent over a one-week period was analyzed using both qualitative and quantitative methods. Through a thematic analysis, we demonstrate that self-disclosure of perceived loneliness takes a variety of forms, from simple statements of “I’m lonely”, through to detailed self-reflections of the underlying causes of loneliness. The analysis also reveals forms of online support provided to those who are feeling lonely. Further, we conducted a quantitative linguistic content analysis of the dataset which revealed patterns in the data, including that ‘lonely’ tweets were significantly more negative than those in a control sample, with levels of negativity fluctuating throughout the week and posts sent at night being more negative than those sent in the daytime.

From 2018: How Persistent Low Expected Returns Alter Optimal Life Cycle Saving, Investment, and Retirement Behavior

From 2018: How Persistent Low Expected Returns Alter Optimal Life Cycle Saving, Investment, and Retirement Behavior. Vanya Horneff, Raimond Maurer, Olivia S. Mitchell. NBER Working Paper No. 24311, August 2018. https://www.nber.org/papers/w24311

Abstract: This paper explores how an environment of persistent low returns influences saving, investing, and retirement behaviors, as compared to what in the past had been thought of as more “normal” financial conditions. Our calibrated lifecycle dynamic model with realistic tax, minimum distribution, and Social Security benefit rules produces results that agree with observed saving, work, and claiming age behavior of U.S. households. In particular, our model generates a large peak at the earliest claiming age at 62, as in the data. Also in line with the evidence, our baseline results show a smaller second peak at the (system-defined) Full Retirement Age of 66. In the context of a zero return environment, we show that workers will optimally devote more of their savings to non-retirement accounts and less to 401(k) accounts, since the relative appeal of investing in taxable versus tax-qualified retirement accounts is higher in a low return setting. Finally, we show that people claim Social Security benefits later in a low interest rate environment.

Research suggests more people find suicide a reasonable response to dire challenges... No recommendations about what to do and how.

The dangerous shifting cultural narratives around suicide. Julie Phillips. Washington Post, Mar 21 2019. https://www.washingtonpost.com/outlook/the-dangerous-shifting-cultural-narratives-around-suicide/2019/03/21/7277946e-4bf5-11e9-93d0-64dbcf38ba41_story.html?utm_term=.c7c37d383bb5

Research suggests more people find it a reasonable response to dire challenges.

Excerpts:

[...]

The data suggests that white and middle-aged Americans are the demographic groups most at risk for suicide. So in one sense, Krueger’s tragedy fits the prevailing pattern — as did the deaths last year of celebrity chef Anthony Bourdain and fashion designer Kate Spade. In general, suicide rates among whites are about three times higher than among blacks and Latinos.

Between 1999 and 2017, U.S. suicide rates increased by 45 percent for men ages 45 to 64 and by 62 percent for women in that age group. As a result, that cohort surged ahead of the 65-plus age group in absolute terms, with a suicide rate of 19.6 per 100,000 — producing, in effect, a new epidemiology of suicide.

There are many reasons for this rise, all of them important. But one underdiscussed explanation is the subtle loosening of taboos around suicide. Surveys suggest that Americans in recent years are more likely to view it as an acceptable reaction not just to terminal illness but also to life setbacks that are emotionally brutal but survivable. (That doesn’t mean these attitudes played a part in any specific recent suicide.)

Other trends have been more broadly reported. The media attention given to the deaths of high-profile people should not distract from the fact that the rising rates of suicide occur disproportionately among working-class and less-educated Americans. In 2014, the most recent year such breakdowns of data are available, men with only a high school diploma were twice as likely to die by suicide as men with a college degree. And although middle-aged men of all educational groups experienced rising suicide rates during the Great Recession, 2007 to 2010, since then rates for college-educated men have slightly declined while those for men with only a high school diploma have continued to rise.

[...]

Yet a possible cultural component of the suicide epidemic demands close attention, too. Research suggests that Americans are becoming more tolerant and accepting of the practice. In some contexts, many Americans might find this tolerance benign — as with suicide, or even assisted suicide, in the end stages of a fatal disease (although that practice has strong critics, too).

But other attitudinal shifts may be more plainly troubling. One way to track these views is through the General Social Survey (GSS), which, since its inception in 1972, has asked a nationally representative sample of Americans about their attitudes toward suicide. In an analysis of changes in attitudes from the 1982-86 period to the 2010-16 period, Yi Tong, now a medical student at SUNY Downstate College of Medicine, and I found that the share of Americans age 18 or older who said people have the right to end their lives in the case of an incurable disease rose from 46.9 percent to 61.4 percent. The percentage who said that being “tired of living and ready to die” was a reasonable rationale for suicide jumped from 13.7 percent to 19.1 percent. And roughly 11 percent of Americans in the later period said that suicide was acceptable during a financial bankruptcy or if one had “dishonored” one’s family — up from about 7 percent, in both cases.

We know that attitudes toward suicide affect behavior. Elizabeth Luth, of Cornell’s medical school, and I examined some 30 years of data on GSS respondents (about 35 percent of whom had died since their interviews) and found that expressions of suicide acceptability were associated with subsequent death by suicide. Beliefs that suicide is acceptable under certain social circumstances (family dishonor and bankruptcy) had the strongest effects on mortality.

Reducing stigma around suicide can be positive — if it means that distressed people become more likely to seek help, for instance. But when and if the belief spreads that the act is acceptable under some conditions, even terminal illness, that may have ramifications we don’t fully understand. We need more research to figure out what messages destigmatize suicide in the good sense, opening the doors to life-saving conversations, and which ones normalize it as a response to crisis, with deadly consequences.

[...]

From 2018... Nice guys finish last: When and why agreeableness is associated with economic hardship

Matz, Sandra C., & Gladstone, Joe J. (2018). Nice guys finish last: When and why agreeableness is associated with economic hardship. Journal of Personality and Social Psychology, Oct 11, 2018. http://dx.doi.org/10.1037/pspp0000220

Abstract: Recent research suggests that agreeable individuals experience greater financial hardship than their less agreeable peers. We explore the psychological mechanisms underlying this relationship and provide evidence that it is driven by agreeable individuals considering money to be less important, but not (as previously suggested) by agreeable individuals pursuing more cooperative negotiating styles. Taking an interactionist perspective, we further hypothesize that placing little importance on money—a risk factor for money mismanagement—is more detrimental to the financial health of those agreeable individuals who lack the economic means to compensate for their predisposition. Supporting this proposition, we show that agreeableness is more strongly (and sometimes exclusively) related to financial hardship among low-income individuals. We present evidence from diverse data sources, including 2 online panels (n1 = 636, n2 = 3,155), a nationally representative survey (n3 = 4,170), objective bank account data (n4 = 549), a longitudinal cohort study (n5 = 2,429), and geographically aggregated insolvency and personality measures (n6 = 332,951, n7 = 2,468,897).

Saturday, March 23, 2019

Why smarter individuals self-report being prosocial and more moral persons? A study on the mediating roles of empathy and moral identity

Why are smarter individuals more prosocial? A study on the mediating roles of empathy and moral identity. Qingke Guo et al. Intelligence, Volume 75, July–August 2019, Pages 1-8. https://doi.org/10.1016/j.intell.2019.02.006

Highlights
•    Intelligence is associated with self-reported prosocial behavior in daily life.
•    Higher intelligence is contributive to emotional sensitivity and a greater concern for others.
•    Highly intelligent individual is more likely to self-identify as a moral person.
•    The intelligence-prosociality association is mediated by perspective taking, empathic concern and moral identity.

Abstract: The purpose of this study is to examine whether there is an association between intelligence and prosocial behavior (PSB), and whether this association is mediated by empathy and moral identity. Chinese version of the Raven's Standard Progressive Matrices, the Self-Report Altruism Scale Distinguished by the Recipient, Interpersonal Reactivity Index, and the Internalization subscale of the Self-Importance of Moral Identity Scale were administered to 518 (N female = 254, M age = 19.79) undergraduate students. The results showed that fluid intelligence was significantly correlated with self-reported PSB; moral identity, perspective taking, and empathic concern could account for the positive association between intelligence and PSB; the mediation effects of moral identity and empathy were consistent across gender.

How to define and measure the extent to which human cognition is rational

Cognitive Success: A Consequentialist Account of Rationality in Cognition. Gerhard Schurz, Ralph Hertwig. Topics in Cognitive Science, January 2019. https://doi.org/10.1111/tops.12410

Abstract: One of the most discussed issues in psychology—presently and in the past—is how to define and measure the extent to which human cognition is rational. The rationality of human cognition is often evaluated in terms of normative standards based on a priori intuitions. Yet this approach has been challenged by two recent developments in psychology that we review in this article: ecological rationality and descriptivism. Going beyond these contributions, we consider it a good moment for psychologists and philosophers to join forces and work toward a new foundation for the definition of rational cognition. We take a first step in this direction by proposing that the rationality of both cognitive and normative systems can be measured in terms of their cognitive success. Cognitive success can be defined and gauged in terms of two factors: ecological validity (the system's validity in conditions in which it is applicable) and the system's applicability (the scope of conditions under which it can be applied). As we show, prominent systems of reasoning—deductive reasoning, Bayesian reasoning, uncertain conditionals, and prediction and choice—perform rather differently on these two factors. Furthermore, we demonstrate that conceptualizing rationality according to its cognitive success offers a new perspective on the time‐honored relationship between the descriptive (“is”) and the normative (“ought”) in psychology and philosophy.

1 How psychologists measure rational cognition

For a number of decades, psychologists have typically employed only one experimental method to study whether human cognition is rational (Lopes, 1991). Their approach—devising two or more alternative hypotheses and a crucial experiment with alternative possible outcomes, each excluding one or more of the hypotheses—has been interpreted as enabling a strong inference (Platt, 1964). In research on the rationality of human cognition this means that the experimental set‐up has been designed such that the data, people's cognitive behavior (reasoning, inference, judgment, or choice), support one of two possible results: Either individuals behave in accord with the chosen benchmark of rationality, or their cognitive behavior, measured against the benchmark, is irrational (and sometimes either deviation from the benchmark has been treated as a sign of irrationality as, for instance, in the case of the conjectures that people neglect base rates or pay too much attention to them or that people suffer from both the gambler's fallacy and the hot‐hand fallacy; see Hertwig & Todd, 2000). Crucially, the benchmarks against which these evaluations are made—and human cognition is found to be rational or not—are commonly assumed to be incontrovertible. That is, the benchmarks are understood to be relatively universal, purpose invariant, content free, and domain general. Their claim to legitimacy often rests on “a priori intuitions”—a notion to which we return later. One of these seemingly incontrovertible benchmarks is the canon of classical logic. Take, for illustration, Wason's influential work on human reasoning (e.g., Wason, 1959, 1960). Far from mincing their words, Wason and Johnson–Laird argued that

    a fallacious inference, in fact, is in some ways like both an optical illusion and a pathological delusion. … and like most pathological delusions, we have encountered cases in which the subjects seem to reveal a stubborn resistance to enlightenment. (Wason & Johnson‐Laird, 1972, p. 6)

This dooming verdict is especially notable because long before Wason, other psychologists concerned with the investigation of reasoning processes strongly opposed the use of logic to define rational thought. An example is Wilhelm Wundt, who equally unequivocally argued that

    at first it was thought that the surest way would be to take as a foundation for the psychological analysis of the thought‐processes the laws of logical thinking, as they had been laid down from the time of Aristotle… . These norms … only apply to a small part of the thought‐processes. Any attempt to explain, out of these norms, thought … can only lead to an entanglement of the real facts in a net of logical reflections. (1912/1973, pp. 148–149)

Wundt doubted that classical logic could serve as the bedrock for descriptive theories of reasoning beyond a “small part” of cognition. By extension, he rejected logic's normative claim for the bulk of cognition. But even the greats could not agree. Jean Piaget, for instance, brushed Wundt's view aside. Inhelder and Piaget (1958) proposed that the mental structures required to process experience develop in a stage‐like progression from infancy to adolescence. Once children reach the highest stage, they possess “Euclid's understanding of geometry, Newton's … understanding of space, time, and causality, and Kant's understanding of logic” (Flanagan, 1991, p. 145). For these developmental psychologists, logic was a key descriptive and normative foundation of the mind's highest stage of reasoning. Moreover, cognitive psychologists and scientists, from Bruner (Bruner, Goodnow, & Austin, 1956) to Fodor (1975) to Evans (1982), took theory testing based on deductive logic, thus following Popper (1959/2005), as the key to human learning. When Wason (1969) examined adults’ reasoning and found discrepancies from the rules of logical deduction, he and other contemporary cognitive psychologists did not challenge the normativity of logic but inferred that something in his carefully constructed selection task “predisposes people to regress temporarily to less sophisticated modes of cognitive functioning” (p. 478).

Yet Wundt's (1912/1973) rejection of logic as the foundation of cognition experienced a renaissance in psychology, although on the basis of very different arguments. Specifically, the normativity of logic came under attack in two ways in the late 1980s and 1990s. According to Cosmides (1989), natural selection did not evolve general‐purpose cognitive algorithms but rather cognitive algorithms that succeed in solving recurrent adaptive problems, such as the threat of being cheated in a social exchange. From this perspective, reasoning obeys a Darwinian and not a formal deductive logic. The second challenge arose in terms of a probabilistic approach being taken to purportedly logical reasoning tasks (Oaksford & Chater, 1994). According to this view, the conclusion that humans reason irrationally results from comparing “apparently irrational behavior … with an inappropriate logical standard” (Oaksford & Chater, 2001, p. 349). Specifically, people's reasoning is better understood in the Wason selection task in terms of a process of inductive hypothesis testing (and a Bayesian model of optimal data selection) than in terms of an “outmoded falsificationist philosophy of science” (Oaksford & Chater, 1994, p. 608). Consequently, probability theory rather than logic should be the normative benchmark. It is, of course, not without irony here that human reasoning has also been famously observed to deviate from the norms of probability theory (Barbey & Sloman, 2007; Kahneman, 2011; Kahneman & Tversky, 1972). Yet, like in research on reasoning, both the evidence for people's proneness to errors in statistical reasoning (Peterson & Beach, 1967) and the appropriateness of the invoked probabilistic norms for human rationality (Gigerenzer, 1996) have been hotly debated among psychologists as well.

There has thus been a history of opposing views on whether classical logic should serve as a universal benchmark for human rationality. Similar arguments have been raised with regard to probability, coherence, and other benchmarks of rationality (see Arkes, Gigerenzer, & Hertwig, 2016; Hertwig & Volz, 2013). We believe that now is a good moment for psychologists and philosophers to join forces and work toward a new foundation for the definition of rational cognition. This article represents a first step in this direction, with one author being a philosopher and one a psychologist. We begin by briefly outlining two recent developments in psychology—ecological rationality and descriptivism—that contribute to the ongoing debate about appropriate frameworks of rational cognition.


2 Ecological rationality and descriptivism

One development is the concept of “ecological rationality” (Arkes et al., 2016; Gigerenzer, Todd, & the ABC Research Group, 1999; Hertwig, Hoffrage, & the ABC Research Group, 2013; Hertwig, Pleskac, Pachur, & the Center for Adaptive Rationality, in press; A. Kozyreva & R. Hertwig, unpublished data; Todd, Gigerenzer, & the ABC Research Group, 2012). This view endorses the premise that rationality is evaluated against some benchmark but argues that contrary to a frequent assumption in psychology, there are no universal benchmarks. What are treated as universal benchmarks—for instance, consistency, coherence‐based rules, modus ponens, or Bayes's rule in probability theory—do not suffice to evaluate behavior as rational. Instead, rationality should be measured in terms of the organism's success—accurate predictions or competitive decisions—in the world. Ecological rationality thus aims to shift the researcher's methodological strategy from the a priori imposition of content‐free norms to studying the organism's goals and achievements within the context of specific environmental structures as well as the mind's undeniable cognitive constraints. Researchers would thus ask: Under what environmental structure is a given cognitive strategy (e.g., heuristic, rule, routine) for the task at hand more accurate than competing strategies that need more information and computation, and under what structure is it not? A strategy is ecologically rational to the degree that it is adapted, in the context of the task, to the informational and statistical structure of an environment. This also means that any strategy is no longer good or bad, rational or irrational per se, but rather it is or is not adapted to the specific task and environment. In addition, it means that a strategy is commonly being tested against some other strategies that may or may not be even better adapted to the specific task and environment (e.g., Gigerenzer & Brighton, 2009; Spiliopoulos & Hertwig, in press).

Although Elqayam and Evans (2011) classified the concept of ecological rationality among nonnormativist positions, they criticized it for being in danger of committing the dubious inference from “is” to “ought” (see also Elqayam & Over, 2016, p. 46). The position they advocate, descriptivisim (Elqayam & Evans, 2011; Elqayam & Over, 2016), is meant to escape the “is–ought” inference trap. The escape is realized by completely eschewing normative concerns. Elqayam and Over proposed that

    the psychology of reasoning and decision making would be better off letting go of normative concerns altogether. Instead of measuring rationality by normative standards, the descriptivist position is that rationality should be measured by the achievement of personal goals. (Elqayam & Over, 2016, p. 7, emphasis added)

To this end, Evans and Over (1996) proposed a distinction between rationality1, measured in terms of achieving one's goals, and rationality2, measured against a priori normative standards, such as classical logic or probability theory. Rationality1 is postulated to be personal and contextual, resulting in instrumental rationality, meaning that an individual behaves in such a way as to achieve his or her personal goals (see also Elqayam, 2012).

In our view, the opposition between descriptivism (rationality1) and normativism (rationality2) that Elqayam and Evans (2011) invoked is misleading because the character of “instrumental rationality” is ambiguous (for other critical objections see Hertwig, Ortmann, & Gigerenzer, 1997). Ordinarily, the assertion that an action is instrumentally rational means that it is rational because it is the appropriate means for some end that, in turn, is assumed to be of value. Thus understood, instrumental rationality does involve a normative dimension insofar as it shifts the normative weight from the end to the means (i.e., to the action; Schurz, 1997, sect. 6.1). There is a second, purely descriptive understanding of instrumental rationality according to which the proposition that an action is instrumentally rational for a given end simply means that the action is appropriate for reaching this end, even if this end is bizarre from a commonsense or intuitive viewpoint. For example, it would sound odd to describe “heavy smoking” as instrumentally rational in regard to the goal of increasing the chances of developing lung cancer or frequent casual sex as instrumentally rational in regard to the goal of contracting a sexually transmitted disease. Yet such descriptive statements would be perfectly fine in this second understanding.

Notwithstanding this criticism, the notions of ecological and instrumental rationality and descriptivism have one thing in common: They object to the reduction of rationality to allegedly universal normative systems, which are, in turn, founded on a priori intuitions that are inaccessible to further justification in terms of their cognitive functionality or success in the world. Next, we turn to the difficulties such intuitions face. To this end, let us dip our toes in some philosophical waters.

3 The problems of justifying rational cognition from a priori norms or intuitions

To appreciate the full force of the foundational issues in question, it helps to briefly consider normative ethics and more specifically the classical distinction between deontological and consequentialist justifications of ethical norms (see Broad, 1967; Frankena, 1963). In deontological frameworks, the justification of norms is rooted in general a priori intuitions about values and duty principles that are assumed to be “good in themselves” (e.g., Kant, 1785/2012). These principles are obligatory, irrespective of the consequences that might follow from our actions. In consequentialist frameworks, in contrast, how correct our moral conduct is will be determined solely by a cost–benefit analysis of the action’s consequences. One example of such a framework is (act) utilitarianism, according to which an action is morally justified if the action’s total good consequences outweigh its total bad consequences (e.g., Mill, 1863/1998). Let us employ the distinction between deontological and consequentialist justification in the context of rational cognition (see Goldman, 1986, p. 97). As in deontological theories of ethics, in apriorist accounts of rational cognition (note that the term deontological is reserved for the domain of ethics), norms are justified by reference to a priori intuitions. Such foundational intuitions could be, for instance, necessity, consistency, or coherence. Generally speaking, a norm or an intuition concerning the rationality of a given cognitive strategy can be described as a priori if either it is considered evident without further justification, or its justification is based on other intuitions that are independent of the consequences of this strategy in a given environment. In contrast, consequentialist accounts of rational cognition justify their benchmarks in terms of what one could call “cognitive success.” This means that these benchmarks acquire “normative legitimacy” through the success of their consequences and not through agreement with some norm such as coherence that is imposed a priori (e.g., transitivity, property alpha, procedural invariance; see table 1 in Arkes et al., 2016).
3.1 Equilibrium justifications and the problem of circularity

In our view, it is highly problematic to enlist a priori intuitions as the foundation for justification of rational norms. Let us explain our concern. After five centuries of failed attempts in the history of rationalist philosophy, including Kant's (1781/1998), to justify principles a priori, there is wide consensus in contemporary epistemology: It is impossible to justify cognitive principles from nothing, which was Kant's understanding of “a priori.” Thus, contemporary philosophers in the rationalist tradition have put the coherence of intuitions at the basis of rationalist justifications that are considered a priori in the sense explained.1
The method of justifying a priori intuitions by the coherence with other intuitions has been called, perhaps somewhat euphemistically and sidestepping the term intuition, the “method of reflective equilibrium” (Cohen, 1981; Goodman, 1955/1983; Rawls, 1971):

    The key idea underlying this view of justification is that we “test” various parts of our system of beliefs against the other beliefs we hold, looking for ways in which some of these beliefs support others, seeking coherence among the widest set of beliefs, and revising and refining them at all levels when challenges to some arise from others. For example, a moral principle or moral judgment about a particular case (or, alternatively, a rule of inductive or deductive inference or a particular inference) would be justified if it cohered with the rest of our beliefs about right action (or correct inferences) on due reflection and after appropriate revisions throughout our system of beliefs. By extension of this account, a person who holds a principle or judgment in reflective equilibrium with other relevant beliefs can be said to be justified in believing that principle or judgment. (Daniels, 2018, sect. 1)

From a consequentialist viewpoint, however, there is a vigorous objection to such “equilibrium justifications.” They are circular. In reply to this objection, several philosophers have argued that even circular justifications may have epistemic value (e.g., Goldman, 1999, p. 85; Psillos, 1999, p. 82). However, there are strong counterarguments showing that such hopes are in vain. Before turning to one, let us clarify that we do not deny that certain justification structures that have been called circular in the literature can have epistemic value (see Hahn, 2011); yet these are of a different sort from the circles involved in equilibrium justifications.2

3.2 Circular justifications and the problem of contradictory intuitions

One key counterargument to the view that circular justifications have epistemic value demonstrates that contradictory rules can be pseudojustified by the same circular argument structure. For example, the circular inductive justification of induction goes as follows: Inductions were successful in the past, whence, by induction, they will be successful in the future. If one accepts this justification, then—to avoid inconsistency—one must equally accept a counterinductive justification of counterinduction3 that runs as follows: Counterinductions were not successful in the past, whence by counterinduction they will be successful in the future (see Douven, 2011, sect. 3; Salmon, 1957; Schurz, 2018). Eventually, circular justification may also be given for fundamentalist doctrines, such as the “rule of blind trust in God's voice,” which a person may hold in reflective equilibrium with the intuition that “God's voice in me tells me that I should blindly trust his voice.”

The fact that equilibrium justifications can easily support contradictory intuitions demonstrates that circular justifications are highly problematic. Because of their circularity, these contradictory intuitions cannot be meaningfully correlated with the world but are rather inescapably subjective in nature. A striking example of an intuition‐based account of rationality in psychology and cognitive science is Cohen's (1981) article “Can Human Irrationality Be Experimentally Demonstrated?” According to Google Scholar, this article has been cited a total of 1,414 times (June 23, 2018). The philosopher Cohen vehemently argued against the bleak implications for human rationality implied especially by the research in psychology on probabilistic reasoning (Kahneman & Tversky's heuristics‐and‐biases program; Kahneman, 2011) and deductive reasoning. For Cohen, rules of logical and probabilistic reasoning such as modus ponens, modus tollens, and Bayes's theorem are based on intuitions about correct reasoning. He put it as follows: “The presence of fallacies in reasoning is evaluated by referring to normative criteria which ultimately derive their own credentials from a systematization of the intuitions that agree with them” (1981, p. 317). From this follows, Cohen argued, that if people's reasoning deviates from such rules, then this merely means that they have different intuitions about correct reasoning than logicians or probability theorists do, and therefore experimenters “risk imputing fallacies where none exist” (1981, p. 330).

The subjective nature of intuition‐based justifications raises the problem of how to arbitrate between competing normative systems. Some have diagnosed this arbitration problem as essentially unsolvable because cognitive norms, goes the argument, will necessarily be based on intuitions, without external standards of cognitive success (Elqayam & Evans, 2011). Consequently, an intuition‐based justification of rationality is doomed to result in a strong form of cognitive relativism (“anything goes”)—a position whose consequences the philosopher Stich (1990) worked out.

3.3 Why a consequentialist account of rational cognition is indispensable

What follows from this discussion? First, we do not deny that intuitions are needed in some areas, for example, in ethics where one inevitably must define what counts as intrinsically valuable. However, the appropriateness of cognitive systems should be evaluated not by intuitions but, so we argue, by demonstrations that these systems have successful consequences in the real world. Cognitive success is thus a concept that brings a consequentialist perspective to the justification of norms for rational cognition. Remember consequentialism (as used in ethics) means that the moral rightness of an act depends only on the consequences of that act. By analogy, an act of a cognitive system is rational insofar as its consequences bear success. For instance, the validity of the rule of modus ponens is established not “by intuition” but by the semantic proof of its strictly truth‐preserving nature: If “p” and “p implies q” are true, then “q” will be true as well, no matter the environment you are in. This justification of modus ponens is consequentialist in nature. Cohen (1981, p. 319) objected that the “if–then” of classical logic deviates from the if–then in natural language. Therefore, according to Cohen (1981, p. 319), intuitions need to be invoked to determine the “right” meaning of the conditional. To this argument, the consequentialist reply is that to assume that there is an “objectively right” meaning is a “rationalistic illusion”—there are only more or less cognitively successful meanings and these can change across contexts (see also Hertwig, Benz, & Krauss, 2008; Hertwig & Gigerenzer, 1999). It is well known that the if–then of natural language has a number of different semantic interpretations (cf. Bennett, 2003). The question of which is cognitively most appropriate should be answered not by reference to intuition but by replacing the ambiguous if–then of natural language with semantically well‐defined conditionals (e.g., strict, uncertain, indicative, counterfactual) and investigating their cognitive properties. In later sections we investigate the cognitive success of different systems of strict and uncertain conditional reasoning, with surprising results. Investigations of this sort are impossible as long as these systems are merely evaluated and justified on the basis of intuition, in particular since a growing dissent of intuitions has emerged in the area of conditional reasoning (see Pelletier & Elio, 1997).

In sum, taking intuitions as sacrosanct would hinder empirical research and rational criticism. We suggest that the better justification of norms of rational cognition is consequentialist in nature. Within a consequentialist account, the severe problems of arbitration, cognitive relativism, and the indeterminate correspondence of intuitions and the world are either removed or less grave—at least so we claim. The reason lies in the promise that all normative systems of reasoning can be measured on a commensurable metric that we call cognitive success. What is it and how can it be measured?

4 What is cognitive success?

Next, we propose a consequentialist account of rational cognition. Our account is in line with Quine's naturalized epistemology (1960) but goes beyond it in its explication and applications of the notion of cognitive success, as well as in its new understanding of the interplay between its descriptive and normative components. What distinguishes the present proposal from all naive sorts of pragmatism is that cognitive systems are evaluated in terms of cognitive rather than practical success indices (such as moneymaking). What is measured by cognitive success is the “cognitive part” of rationality. Cognitive rationality is a precondition for practical rationality, but unlike practical rationality, it abstracts from the question of what ends are normatively right or intrinsically good. In contrast, practical rationality, in the philosophical understanding of this concept, attempts to answer this question. For example, knowing the optimal temperature for roasting meat is “cognitively rational,” but the assessment of the practical rationality of roasting meat depends on one's ethical attitude toward a vegetarian versus nonvegetarian diet.

A consequentialist approach to the definition of rational cognition faces two main challenges. First, how can the value of cognitive success be justified without again presupposing normative intuitions, thus inheriting all the problems outlined above? According to philosophical arguments harking back to Hume (1739/40) and Moore (1903), it is impossible to derive norms solely from the “is,” that is, from empirical facts (Schurz, 1997). Consequently, every instrumental justification of particular norms must assume, besides factual information, more general norms. For example, inferring that calisthenics is good from the fact that it improves fitness assumes that fitness is a general norm. Does this argument then not thwart any attempt to ground the notion of cognitive success in anything but, again, normative intuitions?

Although this objection—every instrumental justification of particular norms must assume more general norms—is logically correct and has useful applications in ethics (Schurz, 2014), we argue that it does not apply to psychology and cognitive science for the following reason: Cognitive success is instrumental for all—or at least most4—purposes. Every real‐world decision problem involves, as a part of it, a ubiquitous cognitive task, namely, predicting which of the available actions will have the maximum expected payoff, in light of a given reward function.5 Greater success in this cognitive task will, by and large, lead to greater success in one's actions, independently of the goals pursued (Schurz, 2014). Is the premise that cognitive success is instrumental for almost all purposes really sufficient for the normative justification of cognitive success? Logically speaking, no, because this premise is descriptive and (as explained above) no “ought” can follow from an “is” by rules of logic alone. However, the missing normative premise that fills the logical gap is relatively harmless: We assume that it is by‐and‐large good to help people attain their personal goals. This is indeed a fundamental and widely shared intuition, though not a cognitive but a moral one.

Moreover, the insight that cognitive success is instrumental for almost all practical purposes helps solve the problem of the apparent relativity of instrumental rationality to one's assumed purposes, which for many authors constitutes a fundamental obstacle to the objectivity of this notion (e.g., Stich, 1990, p. 131). We suggest that the purpose‐invariant core of all forms of instrumental rationality is precisely their cognitive rationality (Kornblith, 2002, p. 158). Thus, there are no separate forms of instrumental rationality for cooks, clerks, and pilots, or for right‐wing and left‐wing politicians. What is common to all these applications of instrumental rationality is their cognitive success. This means that cognitive success is not to be mistaken for moral rightness.

This brings us to the second challenge to a consequentialist approach to defining rational cognition: the meaning of cognitive success. The details will depend on the cognitive task at hand. Yet there must be a core meaning of “cognitive success” that is common to all competing systems of rational reasoning; otherwise, it would be impossible to compare them using the same currency. Above, we argued that every real‐world decision problem involves—or can be reformulated in terms of—some kind of prediction problem. On the basis of this premise, we suggest the following definition:

    The core meaning of the cognitive success of a system (including algorithms, heuristics, rules) is defined in terms of successful predictions, assuming a comprehensive meaning of prediction that includes, besides the predictions of events or effects, predictions of possible causes (explanatory abductions) and in particular predictions of the utilities of actions (decision problems).

Characterizing a decision problem in terms of a prediction task might seem narrow. Yet much of what people do is predicated on implicit or explicit forecasts about how the future will unfold. Choosing a job, getting married, having children and investing in their education, purchasing an apartment, voting for a party, saving for old age, choosing a medical treatment—all these decisions and many others are reached on the basis of predictions about what the future holds. Moreover, focusing on predictions by no means implies that important cognitive processes are ignored. Since reliable predictions are based on an inductive inference from sufficiently informed premises, they engage various nonpredictive subprocesses such as search, memory retrieval, and language processing. Importantly, the major purpose of the predictive reformulation of decision tasks is to measure their cognitive success on a commensurable scale. For example, consider the decision problem of buying the “best” car (relative to the buyer's preferences) where the buyer encounters two websites offering two competing decision methods, M1 and M2, to potential car buyers. Then the claim that method M1 is more appropriate for a certain group of car buyers (e.g., males between the ages of 20 and 30) amounts to the testable prediction that the degree of future satisfaction of car buyers in this group, having used method M1, is significantly higher than those who used method M2.

Upon closer inspection, the predictive success of a cognitive system or (more generally) a cognitive method depends on two components that are commonly in competition and whose optimization thus involves a trade‐off. In the psychological literature, this trade‐off is reflected in the distinction between the ecological validity of a prediction method (Brunswik, 1952; Gigerenzer et al., 1999) and its applicability.6
More precisely, a method's cognitive success can be factorized into the product of these two components as follows:

cognitive succ = ecological validity x applicability,

where applicability is the percentage of targets for which the method renders a prediction, among all intended targets of prediction, and ecological validity is the sum of scores divided by the number of all predictions rendered, and

score (per prediction) = max - loss,

where max is the maximal score that a perfectly accurate prediction can obtain and loss is a monotonically increasing function of the distance between the predicted and the actually observed value of the event variable. From this it follows that

cognitive succ = sum of scores divided by number of all intended targets of prediction.


Ecological validity and applicability of a cognitive method are in competition. One can increase the ecological validity of a method by having it apply only to those few target domains for which the method's predictions are known to be accurate because, for instance, the method has been fitted to this domain. Likewise, one can increase the applicability of a method by applying it also to target domains for which its error rate remains unknown or even known to be high, or by permitting the method to make a random guess in cases where the algorithm does not reach a decision (i.e., in this sense is not applicable). Also note that the definition of the concept of applicability is related to all intended target domains but not to all possible target domains. Thus, a method's cognitive success cannot be deemed to be low because it does not apply to domains that were never intended to be part of the class of target domains. Consider, for illustration, the analogy of a hammer—its “success” is not diminished by the fact that the hammer is not suitable to drill holes. We also emphasize that a method's class of intended targets domains is not an invitation to propose arbitrary reference classes but rather is empirically inferred in terms of the method's purposes across all users. Thus, a method's cognitive success cannot be arbitrarily boosted by winnowing down its intended targets to “easy ones.”

The score that a method earns for each prediction is its maximally achievable score (max) minus its distance to the observed value (loss). The type of loss function7
and max are specified by type and context of the given task.8 Often max is identified with the greatest possible loss; this entails that min, that is, the minimal score, is zero. If loss is identified with the absolute distance function, max is given as the width of the observable value range. For example, if the task consisted in forecasting the next day's mean temperature with values lying in the range between −20°C and +40°C and the loss function is given as the absolute difference between predicted and actual mean temperature, then max is 60°C. If the task is the prediction of probabilities such as that it will rain tomorrow, then, according to a famous result of Brier (1950), the appropriate loss function is not the absolute but the squared distance between the predicted probability and the truth value of the predicted event; thus, max = 1 (true) and min = 0 (false). In the example of people intending to buy a car, a natural loss function might be the absolute difference between mean degree of satisfaction (in an unbiased sample) with the car type recommended by method M1 and that recommended by method M2, with degree of satisfaction measured on a scale ranging, say, from min = 0 to max = 10.

4.1 Some possible objections to cognitive success

Let us freely admit that intuitions can play a role in determining the details of the scoring function. However, robust results should be largely invariant to changes of the scoring functions (see the section on uncertain conditionals below). Another objection to the concept of cognitive success is that it downplays the role of explanations relative to predictions. This challenge can serve as a further test case for our account. Salmon (1984) argued that what distinguishes explanations from predictions is that, whereas predictions can be based on noncausal correlations, explanations must spell out the causes of the event to be explained. Although we agree, we emphasize that causality can easily be embedded into the concept of cognitive success. What distinguishes a causal from a noncausal correlation between a variable X and another one Y is that the effect of an intervention on X will be transmitted to Y only if X is a cause of Y (this is a consequence of the causal Markov condition; see Pearl, 2009). Thus, the cognitive success of causal information resides in its capacity to predict the consequences of (human) actions.

Another account identifies good explanations with argument patterns that unify many empirical phenomena (Kitcher, 1981). However, it can be shown that empirical unification correlates with empirical confirmation and this, in turn, correlates with predictive success (Schurz & Lambert, 1994). The only notions of explanation that are not and should not be covered by our account are those that make the quality of an explanation dependent on its coherence with “intuitions of understanding” and that are inexplicable in terms of causal or unificatory concerns.

The two core components of our notion of cognitive success, ecological validity and applicability, are related to a number of further important evaluative dimensions:

    A method with high ecological validity has a high truth rate9 in those situations where it is applicable; thus, high ecological validity is connected with low risk of error.
    A method with high ecological validity may nevertheless have low cognitive success if it can rarely be recruited due to low applicability.
    A method with high applicability renders predictions possible across many predictive contexts. High applicability therefore suggests that the method has a high information output.
    On the other hand, a method's applicability is inversely related to its cognitive costs, measured in terms of the information input needed and the effort required to process it. The higher the cognitive cost of a method, the more often it will be inapplicable because it exceeds the upper bound of agents’ cognitive resources (see also Payne, Bettman, & Johnson, 1993).

The threefold tensions between risk of error, information output, and cognitive costs create a fitness landscape10
that can explain many facets of the pros and cons of competing systems of rational reasoning. How these cognitive fitness factors interact in concrete cognitive tasks will be discussed next. In particular, the tension between these factors explains why cognitive science needs not a monism but a pluralism of cognitive methods, and why the evaluation of those methods’ advantages and weaknesses should rely not on intuition but on careful comparison of their respective success. Next, we illustrate this point by applying the notion of cognitive success in the domains of classical material conditionals, uncertain conditionals, Bayesian probabilities, and prediction and choice.

4.2 Cognitive success and deductive reasoning

Let us return to classical logic, our introductory example of what many psychologists considered a universal norm of rational cognition in the 20th century. Deductive inferences are, by definition, completely valid—that is, they have maximum ecological validity (1.0): In all situations in which all premises are true, the derived conclusion will invariably be true. Yet this ideal validity of deductive inferences stands in stark contrast to their very low applicability, as emphasized by Wundt (1912/1973; see above). That is, the prevalence of deductive inferences with nontrivial conclusions is low. As an example, consider inferences of propositional logic involving the classical (material) conditional “If P, then Q” (semantically equivalent to “not‐P or Q”). It can be shown that this inference can have a nontrivial conclusion insofar as it is possible to confirm each premise by observations that do not already contain the conclusion. This will be the case if the following condition is satisfied: The verification of the conditional premise “If P, then Q” is based not on the observation of “not‐P” or of “Q,” but rather on an inductively supported belief that expresses (at least implicitly11
) a strict (exceptionless) generality of the form “For all x in a given domain: If P(x), then Q(x)” (see Schurz, 2014, sect. 5.1). Exceptionless regularities (i.e., conditional probabilities of 1.0) are known to be rare in empirical (nonmathematical) domains. What does this mean? It simply means that inferences of propositional logic with nontrivial conclusions are rare. Therefore, their overall cognitive success will be low in these domains, notwithstanding their maximum validity. Only if one could demonstrate that in a specific environment the applicability of deductive reasoning is high could one argue in favor of this system's high cognitive success in this environment. One such environment may be cheater detection, where people can be, under specific circumstances, remarkably successful when measured in terms of modus tollens reasoning (Cosmides & Tooby, 1992). Another domain may be consistency checks in legal reasoning (Arkes et al., 2016).

4.3 Cognitive success and reasoning with uncertain conditionals

Uncertain conditionals are conditionals of the form “If A, then normally B.” They are epistemically acceptable if the associated conditional probability pr(B|A) is “sufficiently” high, that is, higher than a contextually determined threshold α > .5. Systems of probability logic infer further conditionals from sets of uncertain conditionals. There are four well‐known systems of reasoning with uncertain conditionals: O, P, Z, and QC. System O (Hawthorne & Makinson, 2007) is the only system that preserves epistemic acceptability from premises to conclusion for any chosen acceptability threshold. System P is the famous system of probability logic developed by Adams (1975). It guarantees to preserve epistemic acceptability only if the sum of the premises’ conditional uncertainties is smaller than 1.0 minus the acceptability threshold (where uncertainty is defined as 1.0 minus probability; Oaksford & Chater, 2007, p. 111). System Z goes back to Pearl (1990) and makes additional default assumptions that, roughly speaking, maximize the entropy of the distribution under the high‐probability constraints dictated by the premise conditionals (Hill & Paris, 2003). System QC (for “quasi‐classical reasoning”) reasons with uncertain conditionals as if they were exceptionless conditionals of classical logic.

For illustration, assume a small world with only four predicates: “being a bird” (B), “being able to fly” (F), “having wings” (W), and “being male” (M). The known premises are the two uncertain conditionals (a) B ⇒ F (birds can fly) and (b) B ⇒ W (birds have wings), with associated probabilities pr(F|B) = pr(W|B) = .95. System O draws only trivial inferences such as B&(M∨¬M) ⇒ F from Premise a, meaning birds that are either male or not male can fly, with an associated probability of .95. In addition to the previous inference, system P draws the inference B&W ⇒ F from Premises a + b, meaning, birds having wings can fly, with an associated probability of .9. System P does so by applying the law of “cautious monotonicity” and the uncertainty sum rule. In addition to the previous inferences, System Z draws the inferences B&M ⇒ F and B&¬M ⇒ F from Premise a, meaning male birds as well as nonmale birds can fly, with an associated probability of .95. It does so by making the default assumption that the predicates “male” and “being able to fly” are statistically independent (likewise in application to Premise b). Finally, in addition to all previous inferences, System QC draws the “risky” inference of contraposition ¬F ⇒ ¬B, meaning nonflying objects are not birds. This follows from Premise a with an associated probability of .95 (similarly in application to Premise b).

These four systems differ significantly in their predictive power. They become increasingly powerful and, at the same time, more risky and error prone. That is, the applicability (number of derived conclusions) and error probability (number of mistakes made) increase from O to P to Z to QC. From a consequentialist viewpoint, the question is not which of these systems is the right or true one, but which is superior with regard to cognitive success. Schurz and Thorn (2012) performed a cognitive‐success analysis of the Systems O, P, Z, and QC. In their computer simulation an environment with four binary variables a, b, c, d and a randomly generated probability distribution was repeatedly simulated. The possible cases (predictive targets) consisted of all 464 conditionals with conjunctions of one, two, or three unnegated or negated variables in their antecedent or consequent. The task on which the four systems were compared was the derivation of conditionals from four randomly selected base conditionals with conditional probabilities ≥ .7, together with a prediction of their associated conditional probabilities.12
Thus, there were at most 460 conditional probabilities to be predicted. Four different scoring rules for cognitive success were compared. Table 1 presents the results for the ACG (advantage compared to guessing) score, defined as the absolute difference between the predicted and the actual conditional probability for each of the derived conditionals. Although the ordering of the four systems according to their ecological validity is Q > P > Z > QC, their applicability ordering is precisely the inverse, QC > Z > P > Q. The resulting cognitive success ordering is Z > QC > P > O.

Table 1. Cognitive success analysis of four systems of reasoning with uncertain conditionals
System     Applicability (% of 460 intended predictions)     Sum of Scores (ACG score)a     Ecological Validity (range [0, 1])     Cognitive Success (range [0, 1])
O     1.0     4.6     0.92     0.009
P     1.4     5.2     0.82     0.011
Z     10.5     22.5     0.47     0.049
QC     22.9     8.5     0.08     0.018
Note

    a For normalization purposes, the ACG scores in table 2 of Schurz and Thorn (2012) were multiplied by 3.

In light of these results, Schurz and Thorn (2012) concluded that System Z achieves the optimal balance in the trade‐off between deriving true and informative conclusions and avoiding false or uninformative ones.13
Schurz and Thorn (2012) and Thorn and Schurz (2014) investigated three additional scoring rules: PIR (price is right), sPIR (subtle price is right), and EU (expected utility). The qualitative orderings of the ecological validity, applicability, and cognitive success of the four systems were the same across all four success measures, demonstrating the robustness of the results.14

4.4 Success and Bayesian probabilities

Bayesian probabilities are internally coherent degrees of subjective beliefs. Following arguments by Ramsey (1926/1990) and De Finetti (1937/1964), coherence is usually justified as follows: If one interprets degrees of beliefs as fair betting quotients, one is guaranteed to never accept a system of bets that exacts a logically guaranteed loss, that is, a “Dutch book.”15
The Dutch book argument is thus indeed a consequentialist justification as it ties the consequences of a person's subjective probabilities back to monetary outcomes. However, what is thus justified is merely the coherence of probabilities, and this means only that they need to satisfy the basic (Kolmogorovian) probability axioms.16 This is indeed a necessary constraint on rational degrees of beliefs, but by itself it is not sufficient for rational degrees of belief to yield cognitive success. The condition of a coherent fair betting quotient depends solely on the gambler's subjective beliefs and preferences. It does not involve any adaptation to the environment, that is, to the true frequency or statistical probability (frequency limit) of the events betted on. Consider, for example, a subjectivist who repeatedly offers betting odds of 1:1 that she will roll a 6 with an unbiased die. She considers this bet to be fair and is equally willing to accept the opposite bet that she will not roll a 6. She is coherent and will remain coherent even after she has lost her entire fortune. She will be puzzled that while everybody readily accepted her first bet, nobody accepted the opposite bet, even though both are equally fair in her view. Thus, if she ignores the frequentistic chances of the events betted on, she will be unable to explain why she lost everything and others won.

As this, admittedly engineered, example illustrates, the problem of subjective degrees of belief is not their low applicability (an individual's beliefs could discriminate between many states of the world) but their potentially low ecological validity. The Bayesian coherence requirement is too weak to exclude cognitively unsuccessful behavior if one's degrees of belief are not connected with objective truth‐chances (i.e., statistical probabilities; Knight, 1921). There are pertinent methods in Bayesian statistics of establishing this connection (less well‐known than the Dutch book arguments), such as Lewis's “principal” principle (1980/1986) or De Finetti's (1937/1964) equivalent “exchangeability” principle. These principles demand that a person's rational degree of belief (Pr) in an event (E) should have the value r, given that all that the person knows is that the statistical probability (pr) of the corresponding event type E is r, more formally, Pr(E | pr(E) = r) = r (for arbitrary r ∈ [0, 1]). One can prove that the satisfaction of this principal principle is equivalent to the assumption of Bayesian statistics that degrees of belief can be represented as weighted averages of statistical probabilities. Subjective probabilities that satisfy this condition are known to converge toward the true statistical frequencies when the evidence increases infinitely, independently of the assumed prior distributions (Gillies, 2000, p. 71ff; Howson & Urbach, 1993, chapter 14; Schurz, 2013, pp. 165, 236f). It is only if this connection between subjective and objective probabilities is established that Bayesian reasoning can be cognitively successful and decisions based on maximization of subjectively expected utility can maximize one's average utility.

4.5 Cognitive success in prediction and choice

Perhaps more than in any other research area in psychology the tension between apriorist and consequentialist accounts of rational cognition unfolded in the debate about the meaning of bounded rationality in general and the role of heuristics in particular. The heuristics‐and‐biases research program (Kahneman, 2011), possibly the most influential research program in psychology of the last five decades, has consistently invoked the rules of probability theory and statistics as a priori norms for human rationality. Deviations from these norms in people's reasoning were taken as manifestation of irrationality. In Kahneman's (2003) portrayal of the program's research, it “attempted to obtain a map of bounded rationality, by exploring the systematic biases that separate the beliefs that people have and the choices they make from the optimal beliefs and choices assumed in rational‐agent models” (p. 1449). Many of the systematic biases were attributed to the operation of heuristics (e.g., availability, representativeness, and anchoring‐and‐adjustment) that although “quite useful,” sometimes “lead to severe and systematic errors” (Tversky & Kahneman, 1974, p. 1124). On this view, a heuristic's rationality is evaluated exclusively on the basis of its conformity to the norms and not in terms of its potential cognitive success.

This changed with the arrival of the ecological rationality research program, which has redefined the normative study of heuristics; by extension, it interprets bounded rationality in terms of the match between a heuristic and an environment, the two blades in Simon's (1990, p. 7) scissors metaphor. On this view, this match determines the performance and thus the cognitive success of a heuristic. In order to measure cognitive success, researchers of heuristics’ ecological rationality have conducted a wide range of tournaments between simple heuristics and complex strategies commonly considered to be normative. These computer simulations encompass, for instance, the analysis of heuristic inferences about real‐world quantities (e.g., which of two cities has a larger population size; Gigerenzer & Brighton, 2009; Gigerenzer & Goldstein, 1996; Katsikopoulos, Schooler, & Hertwig, 2010) and more recently the analysis of choices between uncertain lottery options (Hertwig, Woike, Pachur, & Brandstätter, in press) and of choices in strategic games (Spiliopoulos & Hertwig, in press). For illustration, consider the tournament involving choice strategies choosing between uncertainty lottery options (Hertwig et al., in press). The simulations implemented 20 choice environments (defined by different payoff and probability distributions) and randomly generated 6,000 choice problems per environment. The innovation in this simulation was that all strategies (with the exception of the omniscient expected value model) learned about the properties of each problem by sequentially taking one draw at a time from each of the options per problem. The strategies then chose what they inferred to be the best option after each sample (learning stopped after 50 rounds).

Table 2 presents the cognitive success of each of the six choice strategies. The normative benchmark for human beings is either the omniscient expected value theory, or, more realistically, the sampling‐based expected value theory. In light of the cognitive success measure, Hertwig et al. (in press) concluded that under uncertainty (when all strategies have incomplete knowledge and need to sample the environment), some simple choice heuristics nearly approximate the performance of the sampling‐based expected value theory—even though they may not take entire swaths of information into account. The well‐performing equiprobable heuristic, for instance, ignores all probabilities and merely calculates the mean of all outcomes within each option, then chooses the option with the highest mean. Indeed, the research on ecological rationality has repeatedly demonstrated that simple heuristics, which curtail search for information and reach decisions without complex calculations, can lead to surprisingly good inferences and predictions relative to complex algorithms based on the principles of logic, probability theory, and maximization.

Table 2. Cognitive success analysis of choice strategies in choice environment requiring learning of the properties of the choice options
Strategya     Applicability (in %)b     Cognitive Success (range [0%, 100%])c
N = 5     N = 20      N = 50
Equiprobable     100     93.1     94.6     93.7
Probable     100     86.4     92.3     93.5
Lexicographic     100     86.4     87.9     88.0
Least‐likely     100     54.2     61.5     64.3
Sampling‐based expected value theoryd     100     94.0     98.3     99.3
Omniscient expected value theory     100     100     100     100

Notes
    a All strategies are described in detail in Hertwig et al. (in press).
    b In this analysis all strategies were always applicable because they could either select the options or choose randomly.
    c Average performance across all 20 choice environments and for N = 5, 20, and 50 samples taken per option (two options with two, four, and eight outcomes) from the environment; the cognitive success metric is normalized such that 100% means that a strategy always selected the option with the higher expected value (as did the omniscient expected value model) and 0% means that a strategy always selected the option with the lowest expected value.
    d The sampling‐based expected value theory can also be implemented in terms of a simple heuristic (i.e., natural‐mean heuristic; see Hertwig et al., in press).

The strategies in Table 2 selected an option randomly in cases where their policy and the information available did not render a choice, that is, were not applicable. For this reason their applicability is always 100% and their ecological validity and cognitive success are identical. In other tournaments measuring cognitive success some competing methods have low applicability, whereas others are always applicable. This is particularly the case in tournaments including meta‐inductive selection strategies. The account of meta‐induction (Schurz, in press; Schurz & Thorn, 2016) is in an important sense complementary to the research program of ecological rationality: Meta‐induction is a general meta‐cognitive strategy designed to choose, in each situation in which it is applicable, a locally optimal method from a given toolbox of candidate methods. Two important meta‐inductive strategies are take‐the‐best17and success‐weighting. Take‐the‐best applies in each round of the tournament. It selects the prediction method that is applicable (i.e., renders a prediction) and that has the best success record in the past. Success‐weighting predicts a weighted average of the predictions of those methods that rendered a prediction in the given round of the tournament, with weights reflecting the methods’ past successes. Table 3 presents the results of applying take‐the‐best and success‐weighting to the results of the Monash University footy tipping competition (MUFTC18). The predictive target was forecasting the 3‐valued results (1, 0, or tie) of matches of the Australian Football League. The tournament included the predictions of 1,071 human participants (Table 3 reports the five human forecasters with the highest success rates, Forecasters 1–5) as well as the predictions of the different meta‐induction strategies including take‐the‐best and success‐weighting.

Table 3. Cognitive success analysis of the Monash University footy tipping competition (after 1,514 rounds)a
Predictor     Applicability in %     Sum of Scores     Ecological Validity (range [0, 1])     Cognitive Success (range [0, 1])
Success‐weighting     100     877     0.579     0.579
Take‐the‐best     100     873     0.577     0.577
Forecaster 1     39     839     0.640     0.554
Forecaster 2     27     811     0.637     0.536
Forecaster 3     13     789     0.666     0.521
Forecaster 4     12     789     0.676     0.521
Forecaster 5     13     787     0.658     0.520

Notes
    a Target was forecasting the results of 1,514 matches of the Australian Football League over eight seasons from 2005 to 2012. The tournament included the predictions of 1,071 human participants and the predictions of various meta‐induction strategies including take‐the‐best and success‐weighting.

The five best human forecasters displayed high performance only in certain rounds and refrained from making predictions in other rounds. The meta‐inductive strategies utilized the predictions of the best human forecaster in each round, with the result that their applicability was 100% and their cognitive success surpassed that of the best human forecasters (with a slight advantage of success‐weighting over the simpler take‐the‐best strategy).

4.6 What does cognitive success mean for the is–ought relationship?

Cognitive success’ intent to focus on the consequences of rational cognition suggests a new view of the relationship between the normative (“ought”) and the descriptive (“is”) dimensions of theories of reasoning. According to the traditional division of labor, it is the task of armchair philosophy to address normative issues, and that of empirical psychology to answer descriptive questions. From the consequentialist perspective of cognitive success, however, empirical results can become normatively relevant, and normative innovations can suggest new empirical questions (see Corner & Hahn, 2013).19
The relationship between the normative and the descriptive, as conceptualized in different accounts of rationality in reasoning—such as apriorism, descriptivism, or ecological rationality—emerges most clearly from the answers they give to the following question: What should one infer from a conflict between descriptively observed and normatively recommended behavior in the context of a cognitive task?

In general, the answers depend on the theoretical positions adopted. Thus, how scholars respond to the gap between “is” and “ought” is diagnostic with regard to the justification of the rationality norms they endorse. Let us assume that an experiment reveals a divergence between how people reason and how they ought to reason according to some standard rational benchmark such as norms of probability theory, logic, or axioms of rational choice. If a scholar adopts an intuition‐based justification of rational cognition, the normatively recommended behavior is not defined in terms of its cognitive success but by reference to a priori intuitions. Thus, the cognitive behavior observed will be judged to be irrational. Alternatively, a scholar may endorse a strong relativism of different systems of intuition. In this case, however, no strong rationality inferences can be drawn (Cohen, 1981; Shier, 2000, p. 78).

In consequentialist accounts, in contrast, both the empirically observed reasoning and the “reasoning” of the normative systems will be evaluated with regard to cognitive success. For example, if logistic regression were regarded as the normative standard for predicting the value of a criterion based on a set of cues, then the cognitive success of this normative standard, assuming some statistical knowledge base, could be measured against the cognitive success of people's predictive inferences from the same input (see also Gigerenzer & Brighton, 2009). This opens up a new option for responding to conflicts between empirical observations and normative recommendations. The cognitive success of observed reasoning is not necessarily worse than that of the normative system. Indeed, observed reasoning may, in fact, even outperform normative recommendations. As mentioned before, evidence for the latter has been compiled in research on bounded and ecological rationality (Gigerenzer & Brighton, 2009; Gigerenzer, Hertwig, & Pachur, 2011; Hertwig et al., 2013, in press; Todd et al., 2012). If the observed cognitive behavior outperforms the normative system, the consequentialist would need to conclude that the assumed “normative system” is second best and, thus, can no longer be invoked to derive normative recommendations.20
If, however, observed behavior scored lower on cognitive success than the normative system, the consequentialist's conclusion would depend on a second theoretical choice that is open to consequentialists but not to intuition‐based accounts, namely, attitudes toward cognitive adaptationism. This position assumes that human cognition is near‐optimally adapted to its relevant environments. Therefore, a consequentialist proponent of cognitive adaptationism may be inclined to argue that the assumed measure of cognitive success is inappropriate and in need of revision. In contrast, a nonadaptationist consequentialist would conclude, faced with evidence that observed behavior's cognitive success is surpassed by that of the normative system, that human cognition is below par.

Let us explain the relationship between cognitive consequentialism and cognitive adaptationism in more detail. One might think that cognitive consequentialism entails cognitive adaptationism because the former evaluates cognitive systems by their cognitive success and cognitive success entails being well adapted. This reasoning, however, mistakes “is” and “ought.” Cognitive consequentialism makes the normative claim that cognitive systems should be evaluated in terms of their cognitive success. This implies the normative claim that, ceteris paribus, cognitive systems should be well adapted to their environment. However, cognitive adaptationism is not a normative requirement but an empirical thesis, stating that because humans are the product of evolutionary selection processes, they will be cognitively well adapted. This may or may not be the case—an issue to which we return below. For the present discussion, however, it is important to note that cognitive adaptationism is not entailed by the normative requirement of cognitive consequentialism. Consequently, a cognitive consequentialist can be more or less inclined toward the choice to assume cognitive adaptationism. This choice, in turn, will determine the response to an instance in which actual cognition scores lower on cognitive success than the normative system.

4.7 Cognitive consequentialism and the issue of adaptationism

Let us finally discuss cognitive adaptationism as found in Anderson's (1990, 1991a,b) work in more detail because, prima facie, his rational analysis shares significant resemblances with our account of cognitive consequentialism. Anderson's method consists of five iterative steps (Anderson, 1991a, p. 473):

    Specify the goals of the cognitive system.
    Develop a model of the environment to which the system is adapted.
    Make minimal assumptions about computational limitations, such as memory storage and computation time.
    Derive the optimal behavior given in (1)–(3) above.
    Finally, test empirically whether the predictions of the optimal behavior derived in (4) are confirmed by human cognitive performance; if not, then the task–environment model developed in (1) + (2) has to be revised.

Anderson has applied rational analysis to domains such as memory analysis, categorization theory, causal inference, and problem solving.21Regarding Step 1, in these domains Anderson identifies the goal of the cognitive system as some kind of predictive inference. Thus, there is agreement between Anderson's analysis of cognitive goals and our definition of cognitive success. Also Steps 2 and 3 are consistent with a cognitive success analysis, except that in Step 3 we would argue that “minimal” assumptions should be replaced by realistic assumptions about computational limitations (see Simon, 1990). The first crucial difference to our account appears in Step 4. The consequentialist account does not intend to “derive” the optimal method from the description of the task and environment, because apart from very simple cases this is impossible. In the area of prediction methods, the nonexistence of a universally optimal method is the content of Wolpert's (1996) famous no free lunch theorem (cf. Schurz, 2017). Simon (1991) demonstrated that what does the real work in Anderson's derivations are specific auxiliary assumptions about the cognitive system and its environment. We mostly agree with Simon's critique of Anderson's optimal adaptation hypothesis: All that rational analysis can do is consider all available but not all possible competing methods for a given task and investigate their cognitive success. This is what the consequentialist account suggests.

Cognitive success, unlike optimal adaptation, thus behaves similarly to how Simon portrayed natural selection:

    The theory of natural selection is not an optimizing theory for two reasons. First, it can, at best, produce only local optima, because it works by hill‐climbing up the nearest slope. It has no mechanism for jumping from peak to peak… . Second, it selects only among the alternatives that are available to it. (1991, p. 29)

This brings us to Anderson's Step 5. This step presupposes the adaptationist thesis that human cognitive behavior is nearly optimally adapted (Anderson, 1991a, table 1, p. 473). As a general claim, such an “evolutionary optimism” is difficult for several reasons. First, evolutionary selection sometimes produces suboptimal and even dysfunctional adaptations (Ridley, 1993, p. 343f). Second, although genetic evolution optimizes the biological reproduction rate, it is less clear how this process relates to cognition. Anderson acknowledged the fact that evolutionary selection does not find a global optimum but merely a local one. However, there is a world of difference between a global and a local maximum: It can be as large as the difference between a sand hill and Mount Everest. All single constraints on cognitive processes dictated through the biological architecture of humans’ brains (see Jones & Love, 2011) are concealed in this difference.

In contrast to rational analysis, cognitive consequentialism does not imply cognitive adaptationism, though it is compatible with it. Obviously, the human brain is well adapted in many respects, but not in all. Therefore, we suggest that the view of rational cognition that appears most defensible and productive for contemporary cognitive science is that of a cognitive consequentialism that is not bound to strong adaptationist assumptions. In conclusion, the consequentialist account proposes to modify Anderson's Steps 4 and 5 as follows:

    4' Derive the consequences of the available competing cognitive methods [given the output of (1)–(3)] and test their cognitive success.
    5' Compare the locally optimal method [i.e., the output of (4)] with the actual human behavior.
        5'.1 If they agree, recommend the locally optimal method and infer that human cognition is well adapted.
        5'.2 If they disagree, two cases are possible:
            5'2.1 If human behavior outperforms the locally optimal method, search for better cognitive methods (to thus eventually explain human behavior): Backtrack to (4) and iterate.
            5'2.2 If human performance is worse than the locally optimal method, search for local constraints on the mind's cognitive mechanisms that can explain the disagreement. Backtrack to (3), add these constraints, and iterate. At the same time, recommend the locally optimal method as a rational improvement of intuitive human cognition that can be learned by cognitive training.

In other words, at this point cognitive consequentialism potentially has educational implications.

5 Conclusion: New questions about rational cognition

The study of human cognition and its rationality seems inseparable from the question of how successful it is. In psychology and economic research, rationality of human cognition has often been equated with coherence, that is, rules for internal consistency, often defined by propositional logic and probability theory (see Arkes et al., 2016). However, for decades, psychologists have disagreed over how well coherence‐based normative systems describe human cognition and which coherence‐based systems (logic, probability theory, or decision theory) should be granted the status of normative benchmarks for cognition (see our introduction). We have discussed the problems that arise when normative systems are justified by reference to a priori intuitions, as is typically the case. As an alternative and a potential response to some of these problems, we propose a consequentialist account of normative systems. The major tenets of this account are as follows:

    Traditional normativism fails because a priori intuitions are inadequate as justifications of norms of rational cognition.

    Traditional descriptivism fails because norms of rational cognition are inevitably needed as benchmarks for successful reasoning.

    Norms of rational cognition are better justified from a consequentialist perspective, that is, in terms of their cognitive success.

    The concept of cognitive success of a cognitive method assumes that all decision tasks can be reformulated as prediction tasks.

    Cognitive success is defined as the product of ecological validity and the method's applicability. Determining the available method's cognitive success permits one to compare them on the same scale.

    Cognitive consequentialism is related to ecological rationality to the extent that cognitive success depends on the given cognitive task and a specific environment.

We hope and believe that this approach (or a similar consequentialist concept) offers a way to overcome the trite division of labor between the empirical study of the mind and philosophy. This approach raises new and interesting questions. For instance, what does cognitive success imply for research that has drawn strong conclusions about the (ir)rationality of human cognition (e.g., the heuristics‐and‐biases research program; Kahneman, 2011)? Or, assuming that the success of different cognitive methods depends on specific environments and that no method succeeds in all environments, will there be metamethods that are able to select the best method for the environment in question (see “meta‐induction”; Schurz, in press)? Finally, to what extent is cognitive success adaptive in an evolutionary sense, and how does the answer to this question influence the understanding of the relation between is (observed cognitive behavior) and ought (normatively recommended behavior)? We do not have answers to these and other questions, but we hope that we have convinced the reader that it is timely to ask these questions, thus leaving some skirmishes of the “rationality wars” behind us (Samuels, Stich, & Bishop, 2012) and turning the question of what rational cognition is into a less dogmatic and a more empirical one.

Voters frequently evaluate objective conditions through a perceptual screen, seeing a stronger economy & more peaceful world when their party rules; this assessment is polarizing increasingly

Partisanship, Political Awareness, and Retrospective Evaluations, 1956–2016. Philip Edward Jones. Political Behavior, March 23 2019. https://link.springer.com/article/10.1007/s11109-019-09543-y

Abstract: A long line of research shows that voters frequently evaluate objective conditions through a perceptual screen, seeing a stronger economy and more peaceful world when their party is in power. We know less about how and why these partisan perceptual differences have changed over recent history, however. This paper combines ANES measures of retrospective evaluations from 1956 to 2016 and shows that partisan differences (1) have increased significantly over the past few decades across all types of assessments; (2) are greatest, and have changed the most, amongst the most politically aware; and (3) closely track changes in elite polarization over this time period. The extent of partisan disagreement in retrospective evaluations is thus not constant, but rather contingent on attributes of the voter and the political context. Greater political awareness and more polarized politicians result in larger partisan perceptual differences, as the most engaged citizens are the most likely to receive and internalize cues about the state of the world from their party’s elites.

Keywords: Retrospective evaluations Partisanship Political awareness

I find that sharing a gender identity not only fails to unite women who are partisan rivals but, in fact, further highlights their rivalry

When Common Identities Decrease Trust: An Experimental Study of Partisan Women. Samara Klar. American Journal of Political Science, June 6 2018. https://doi.org/10.1111/ajps.12366

Abstract: How does sharing a common gender identity affect the relationship between Democratic and Republican women? Social psychological work suggests that common ingroup identities unite competing factions. After closely examining the conditions upon which the common ingroup identity model depends, I argue that opposing partisans who share the superordinate identity of being a woman will not reduce their intergroup biases. Instead, I predict that raising the salience of their gender will increase cross‐party biases. I support my hypotheses with a nationally representative survey of 3,000 adult women and two survey experiments, each with over 1,000 adult women. These findings have direct implications for how women evaluate one another in contentious political settings and, more broadly, for our understanding of when we can and cannot rely upon common identities to bridge the partisan divide.

Once more: We are aggressive, but that is nothing compared to many other species. Interview with Anthropologist Richard Wrangham

Interview with Anthropologist Richard Wrangham. Johann Grolle. Der Spiegel, March 22, 2019. http://www.spiegel.de/international/interview-with-anthropologist-richard-wrangham-a-1259252.html

'Those Who Obeyed the Rules Were Favored by Evolution'

British anthropologist Richard Wrangham believes our humanity began with the murder of a tyrant. In an interview with DER SPIEGEL, he explains why homo sapiens are so murderous, while also being among the most peaceful species.

DER SPIEGEL: Professor Wrangham, you're interested in aggression. Why did you go to the Ugandan jungle to research it for it?

Wrangham: The jungle is full of aggression. One of my favorite things is to go for a walk in the forest, close my eyes and just listen. I hear the trills of birds, the chirping of insects, the calls of monkeys, sometimes even the sound of an elephant. And what is it that is so soothing and pleasant for us? Most of it is produced by males shouting out their maleness, their dominance. In other words, it is the language of aggression.

DER SPIEGEL: In your studies of chimpanzees, did you always focus on aggression?

Wrangham: No. First, I studied how these animals feed - -- which is a completely different subject. But when you follow a chimpanzee from dawn till dusk, the importance of aggression just hits you in your face. Compared to us humans, the rate of their aggression is enormously higher.
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DER SPIEGEL: Can you give an example?

Wrangham: Take the behavior of males on the threshold of adulthood: They almost ritually attack one female after the other until each one shows signs of submission. Only when a male has achieved physical dominance over every single female is he able to enter the male hierarchy and compete there for the highest possible rank.

DER SPIEGEL: And does this brutality enable them to succeed?

Wrangham: Absolutely. Once a male is fully adult, he continues to attack females even when they give submissive signals to him. The male who beats a particular female the most is the most likely to be the father of her next offspring.

DER SPIEGEL: How do you feel when you watch something like this?

Wrangham: It upsets me. I do love chimpanzees, and I am fascinated by them. I appreciate the wonderful moments I experience with them. But they also have nasty sides. Watching a male beating up a female is horrendous - -- just as it is horrendous watching these animals tearing the guts out of a monkey that is still alive. The essential violence of chimpanzees' carnivory is thoroughly off-putting. It is why I haven't eaten meat for 40 years.

DER SPIEGEL: Is it fair for a scientist to describe this behavior as "nasty"?? Is aggression evil?

Wrangham: It would seem inhuman not to recognize that some of the chimpanzees' behaviors are deeply unpleasant. And is aggression evil? Yes, I think so, at least when it involves physical violence that is inflicting pain. Violence is the opposite of virtue. I think that a major object of human endeavor and societal ambition should be to reduce violence.

DER SPIEGEL: In this sense, at least, we humans seem to have taken a step away from chimpanzees.

Wrangham: Yes. If you trapped 300 chimpanzees who did not know each other in a plane for eight hours, many of them probably wouldn't leave it alive. People, on the other hand, barely touch each other on a long-haul flight. The level of violence has been monitored in a group of hunters and gatherers in Australia. These Aborigines suffer from strong social upheavals, alcohol abuse is high. Still, even under these conditions, the frequency of violence among these people is 500 to 1,000 times lower than among chimpanzees.

DER SPIEGEL: Though people are also capable of torturing each other, and our history is replete with war and genocide. Given this, how can you speak of the placidity of human nature?

Wrangham: You're right, it seems paradoxical. But it is important to understand that there are two different types of aggressiveness. Violence in war is mostly planned, deliberate and cold-blooded. The everyday aggression of chimpanzees, on the other hand, is spontaneous, short-tempered and born directly from the moment. Here we have one of the great mysteries of human nature: Why do we treat each other so peacefully in everyday life when we are capable of such a degree of deliberate cruelty?

DER SPIEGEL: Is this deliberate, planneding form of aggression a peculiarity of humans?

Wrangham: Not at all. You find it among chimpanzees as well. Konrad Lorenz believed that animals do not kill each other. But he was proven wrong. I was part of Jane Goodall's team, who first observed how chimpanzees attacked members of neighboring groups to kill them deliberately. The discovery of warlike patterns of aggression among chimpanzees was one of the big surprises of our research.

DER SPIEGEL: In other words, we have inherited the brutal part of our nature from our ancestors, whereas the peaceful part distinguishes us from them?

Wrangham: Yes, that's one way of putting it.

DER SPIEGEL: You write that humans owe their placidity to their own domestication. What do you mean by that?

Wrangham: We humans exhibit a number of biological characteristics that are more typical of pets than of wild animals, including a very low rate of face-to-face aggression. The reason that I attribute our peaceableness to our having been domesticated is because we share with our pets and farm animals some of these other characteristics, which we now call a domestication syndrome. Charles Darwin was already fascinated by this phenomenon. He studied domestic animals, and he noticed that they share a multitude of peculiarities not found in wild animals.

DER SPIEGEL: Like what?

Wrangham: Many pets have white spots in their fur. They often have floppy ears, a short face or a curved tail. All these traits are rare among wild animals, but common among pets. And the interesting thing is that humans didn't select their pets specifically for these traits.

DER SPIEGEL: How do you know? Maybe Stone Age farmers were fond of pigs with floppy ears or cows with spots.

Wrangham: We know it thanks to the ingenious experiments of the Russian geneticist Dmitri Belyaev. He bred silver foxes with only one trait in mind: he He selected the most tame and peaceful individuals from each generation. And behold, many of the other typical characteristics of pets emerged on their own.

DER SPIEGEL: Cuddly foxes sound cute. Have you seen them yourself?

Wrangham: No, unfortunately I haven't. But my student Brian Hare went to Novosibirsk, where Belyaev's team continues to work. He wondered why dogs understand human signals better than wolves. He assumed that it might be a result of targeted selection by humans. But then he examined Belyaev's foxes and found that they also know how to interpret human signals. So the ability to understand human signals seems to be another trait, like white patches of fur, that emerges as a side effect of selection for less aggression.

DER SPIEGEL: You claim humans are also domesticated. What makes you think that? We don't have white spots, or floppy ears, or a curly tail.

Wrangham: You're right. We have no tail, so it can't bend. But if you look at our skeleton, you will find a lot of peculiarities that are characteristic of pets. Four of them stand out compared to our ancestors: a shorter face; smaller teeth; reduced sex differences, with males becoming more female-like; and, finally, a smaller brain. This latest development is particularly fascinating. In fact, the evolution of humans is naturally characterized by a continuous increase in brain size. But it turns out this trend has reversed in the last 30,000 years.

DER SPIEGEL: How could a package of traits like that develop when it was not under any selection pressure?

Wrangham: We are still not sure what biological mechanisms produce the domestication syndrome. But we have circumstantial evidence. It is noticeable, for example, that many of the domestication traits are typical for young animals ...

DER SPIEGEL: ... in other words, dogs resemble wolf pups, just as we resemble Neanderthals who never reached adulthood?

Wrangham: Yes. Young animals are usually characterized by a lower level of reactive aggression. One way nature might evolve reduced aggressiveness is by allowing creatures to reach adulthood while still being emotionally juvenile. All the other juvenile traits are then nothing but side effects of the reduction of aggression.

DER SPIEGEL: You said earlier that our brain began shrinking 30,000 years ago. Is this when humans started getting tamed?

Wrangham: No. We can follow the process of domestication pretty thoroughly in the fossil record. According to that, the development started about 300,000 years ago. Brain size only began to decrease at the very end.

DER SPIEGEL: Obviously, we domesticated dogs, horses and cats, but who domesticated us?

Wrangham: The word "domestication" is somewhat misleading. It implies a relationship with humans. But Belyaev's fox experiments show us that only the selection of non-aggressive behavior is important. Whether this selection happens in captivity or the wild doesn't matter. While some species have been domesticated by humans, others have been domesticated, in the sense of reducing their aggressiveness, on their own. We are one of the species that domesticated ourselves.

DER SPIEGEL: What kind of domesticated animals are there in the wild?

Wrangham: The best example can be found among our closest relatives: the bonobos. They look very similar to chimpanzees, but their skulls show the characteristics of domestication: a shorter face, smaller teeth, a smaller brain, and reduced differences between the sexes.

DER SPIEGEL: And their behavior is more peaceful?

Wrangham: Dramatically so. When a bonobo male attacks a female, she will call for help, and within minutes the male will face an alliance of females who put him in his place.

DER SPIEGEL: Females bonobos domesticated the males?

Wrangham: Yes, probably. The bonobos live in a habitat that allows females to travel together all the time, unlike chimpanzees. This has favored social alliances among the females.

DER SPIEGEL: Are bonobos the better chimpanzees?

Wrangham: They're much nicer to each other, that's true. But of course bonobos also have some dark sides. There was this guy in France who started a commune based on the principle of living the bonobo way. He ended up in prison for pedophilia.

DER SPIEGEL: What about humans? Did women civilize us men as well?

Wrangham: That seems unlikely. There are many mythological memories of an era in which power was in the hands of women, but today there is no such thing as matriarchy anywhere in the world, and we have no evidence that there ever was.

DER SPIEGEL: If it wasn't women, who tamed men?

Wrangham: Here we enter the terrain of speculation, because fossils don't tell us exactly what happened. What we have to do instead is to see how today's hunters and gatherers treat individuals that behave aggressively. There are, in fact, even in these generally peaceable peoples, some individuals who, like alpha chimpanzees, try to dominate the others by violence. How do the members of such a community react - -- without prisons, without military, without police? There is only one way for them to defend themselves against the determined perpetrator: He is executed. The killing is done by agreement among the other men in the society.

DER SPIEGEL: You argue that this is how aggressiveness was systematically eradicated from the gene pool of mankind?

Wrangham: Well yes, aggressiveness was reduced, even if it was not eradicated. Virtue seems to have evolved from something as violent as killing. But don't misunderstand. I am not advocating executions in today's world. Justice is fallible, so the death penalty inevitably leads to the killing of innocent people; furthermore, there is no evidence that it really effectively deters people from committing crimes.

DER SPIEGEL: It is quite a daring hypothesis to argue that the death penalty has made us what we are. How did you come up with it?

Wrangham: It was when I read a book by Christopher Boehm entitled "Hierarchy in the Forest". In this book, he describes how aggression in communities of hunters and gatherers is controlled by executions. My goodness, I thought when I read this, maybe this mechanism has even shaped our evolution?

DER SPIEGEL: If anyone who strives for power is killed, does that mean there are no chiefs in communities of hunters and gatherers?

Wrangham: Yes, hunter-gatherers are very egalitarian in their relationships among men.

DER SPIEGEL: So when the fathers of the American constitution famously proclaimed, "All men are made created equal,", they were really just reanimating a principle that has shaped our species over many millennia?

Wrangham: Yeah. Isn't that fascinating? And even the fact that the Declaration of Independence only mentions men, but not women, corresponds to the situation in communities of hunters and gatherers. Egalitarianism among them only applies to men. Women, on the other hand, are dominated by men.

DER SPIEGEL: And how do you think it all began? Why did the men of lower rank eventually join together to kill the tyrant?

Wrangham: Well, it's quite dangerous to rebel against the alpha male. The one who throws the first stone will risk his life. No lion or chimpanzee would dare to do that. Only humans were able to squat together and whisper: "Let's meet at the big stone, then attack and kill him."

DER SPIEGEL: In other words, language facilitated the rebellion of the underdogs?

Wrangham: Yes, because only by discussing and planning how to kill the tyrant could they be sure that they wouldn't be harmed themselves.

DER SPIEGEL: Unlike all animals, man is capable of moral action. In your book, you claim that this is another consequence of the beta male's uprising against the alpha?

Wrangham: Yes. At some point the community of beta men united against the powerful. Then they realized that from now on they themselves had the power to kill everyone in the group. They established rules for living together, and anyone who violated them had to fear death. In this way, those who obeyed the rules were favored by evolution.

DER SPIEGEL: Submission made us moral beings?

Wrangham: You put it in a handy phrase. It may be disillusioning. But I'm afraid it was like this: Morality was born in an effort not to be targeted by the justice of the community.

DER SPIEGEL: And little by little, cowardice wrote itself into our genes.

Wrangham: Yes. And the fossil record suggests that the domestication process even accelerated.

DER SPIEGEL: Is it now complete? Or is man still taming himself?

Wrangham: There is, at least, no indication that the process has come to a halt.

DER SPIEGEL: What will we humans look like after another 10,000 generations?

Wrangham: That's speculative, of course. But if the domestication process continues as it has, we will probably look even more childlike than we do nowadays. The juvenile features will be even more exaggerated: the high forehead, the big eyes, the narrow chin.

DER SPIEGEL: The ultimate in anti-aging.

Wrangham: That's one way of looking at it.

DER SPIEGEL: Professor Wrangham, thank you for this interview.

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Check also The phylogenetic roots of human lethal violence. José María Gómez et al. Nature volume 538, pages 233–237 (October 13 2016), https://www.bipartisanalliance.com/2018/02/the-phylogenetic-roots-of-human-lethal.html