Monday, September 21, 2020

Starks & colleagues speculated that HIV infection could alter host behavior in a manner that facilitated the spread of the virus; retrospective and self-report data from five studies now support this hypothesis

Does HIV infection increase male sexual behavior? Philip T Starks, Maxfield M G Kelsey, David Rosania, Wayne M Getz. Evolution, Medicine, and Public Health, eoaa030, September 16 2020.

Abstract: After 40 years of intense study on HIV/AIDS, scientists have identified, amongst other things, at risk populations, stages of disease progression, and treatment strategies. What has received less attention is the possibility that infection might elicit an increase in sexual behavior in humans. In 2000, Starks and colleagues speculated that HIV infection could alter host behavior in a manner that facilitated the spread of the virus. Retrospective and self-report data from five studies now support this hypothesis. Individuals with acute – versus nonacute – stage infections report more sexual partners and more frequent risky sex. Additionally, male sexual behavior increases non-linearly with HIV viral load, and data suggest a potential threshold viral level above which individuals are more likely to engage in risky sexual behavior. Taken together, these data suggest that HIV infection influences male sexual behavior in a manner beneficial to the virus. Here, we present these findings, highlight their limitations, and discuss alternative perspectives. We argue for increased testing of this hypothesis and advocate for increased public health measures to mitigate the putative impact on male sexual behavior.

Lay Summary: In 2000, Starks and colleagues speculated that HIV infection could alter host behavior in a manner that facilitated the spread of the virus. Retrospective and self-report data from five studies now support this hypothesis. We argue for increased testing of this hypothesis and advocate for increased public health measures to mitigate the putative impact on male sexual behavior.

Topic: hivdisease progressionsex behaviorsexual partnersviral load resultinfectionspublic health medicineviruseshiv infectionsself-report

Compensatory conspicuous communication: Low status increases jargon use; experiments provided a causal link from low status to jargon use

Compensatory conspicuous communication: Low status increases jargon use. Zachariah C. Brown, Eric M. Anicich, Adam D. Galinsky. Organizational Behavior and Human Decision Processes, Volume 161, November 2020, Pages 274-290.


• Experiencing low status increases the use of jargon.

• Low status increases jargon use because it activates evaluative concerns.

• Archival analyses found a low status → jargon effect across 64 k dissertation titles.

• Experiments provided a causal link and mediation path from low status to jargon use.

• The use of acronyms also serves a status compensation function.

Abstract: Jargon is commonly used to efficiently communicate and signal group membership. We propose that jargon use also serves a status compensation function. We first define jargon and distinguish it from slang and technical language. Nine studies, including experiments and archival data analyses, test whether low status increases jargon use. Analyses of 64,000 dissertations found that titles produced by authors from lower-status schools included more jargon than titles from higher-status school authors. Experimental manipulations established that low status causally increases jargon use, even in live conversations. Statistical mediation and experimental-causal-chain analyses demonstrated that the low status → jargon effect is driven by increased concern with audience evaluations over conversational clarity. Additional archival and experimental evidence found that acronyms and legalese serve a similar status-compensation function as other forms of jargon (e.g., complex language). These findings establish a new driver of jargon use and demonstrate that communication, like consumption, can be both compensatory and conspicuous.

Rolf Degen summarizes: People willingly accept inconveniences in order to satisfy their curiosity, even if the sought for information is unpleasant or will put them in a bad mood

The seductive lure of curiosity: information as a motivationally salient reward. Lily Fitz Gibbon, Johnny King LLau, Kou Murayama. Current Opinion in Behavioral Sciences, Volume 35, October 2020, Pages 21-27.

Rolf Degen's take:


• Curiosity is a powerful motivator of information-seeking behavior.

• People risk negative experiences to satisfy curiosity.

• Empirical evidence reveals parallels between information and extrinsic rewards.

• Incentive salience may provide motivation for information beyond its expected value.

Abstract: Humans are known to seek non-instrumental information, sometimes expending considerable effort or taking risks to receive it, for example, ‘curiosity killed the cat’. This suggests that information is highly motivationally salient. In the current article, we first review recent empirical studies that demonstrated the strong motivational lure of curiosity – people will pay and risk electric shocks for non-instrumental information; and request information that has negative emotional consequences. Then we suggest that this seductive lure of curiosity may reflect a motivational mechanism that has been discussed in the literature of reward learning: incentive salience. We present behavioral and neuroscientific evidence in support of this idea and propose two areas requiring further investigation – how incentive salience for information is instigated; and individual differences in motivational vigor.

Rolf Degen summarizes... Large parts of our life are governed by "phantom rules", flexible clauses whose violation we only find offensive when we see fit

Wylie, Jordan, and Ana P. Gantman. 2020. “Doesn’t Everybody Jaywalk? On the Motivated Enforcement of Frequently Violated Rules.” PsyArXiv. September 21. doi:10.31234/

Rolf Degen's take:

Abstract: We propose the existence of a subclass of explicitly codified rules— phantom rules—whose violations are frequent, and whose enforcement is motivated (e.g., jaywalking). These rules differ from other rules (e.g., no traveling in basketball) and laws (e.g., theft) because they do not appear legitimate. Across three experiments, we recruited U.S. participants from Amazon MechanicalTurk and Prolific (N = 464) and validated each feature of our definition. In Experiment 1, participants classified phantom rules as illegal and frequent. In Experiment 2, we found that phantom rules (vs. social norms) are more morally acceptable, but more justifiably punished, allowing for the motivated enforcement found in Experiment 3. We hypothesized and found people judge phantom rule violations to be more justifiably enforced when they were already motivated to punish. Phantom rule violations are judged to be morally worse and more justifiably punished when the person who violated the phantom rule also violated a social norm (vs. phantom rule violation alone). Phantom rules are codified rules, frequently violated, and enforced in a motivated manner.

Criminalization of sex work increases sexually transmitted infections among female sex workers by 58 pct, driven by decreased condom access & use; earnings among women decreased, making easier that children begin working to supplement income

 Crimes Against Morality: Unintended Consequences of Criminalizing Sex Work. Lisa Cameron, Jennifer Seager, Manisha Shah. NBER Working Paper No. 27846, September 2020.

Abstract: We examine the impact of criminalizing sex work, exploiting an event in which local officials unexpectedly criminalized sex work in one district in East Java, Indonesia, but not in neighboring districts. We collect data from female sex workers and their clients before and after the change. We find that criminalization increases sexually transmitted infections among female sex workers by 58 percent, measured by biological tests. This is driven by decreased condom access and use. We also find evidence that criminalization decreases earnings among women who left sex work due to criminalization, and decreases their ability to meet their children's school expenses while increasing the likelihood that children begin working to supplement household income. While criminalization has the potential to improve population STI outcomes if the market shrinks permanently, we show that five years post-criminalization the market has rebounded and the probability of STI transmission within the general population is likely to have increased.

63-year-old man, after gunshot to the head, became “content,” light-hearted, and prone to joking and punning; prior to his brain injury, he suffered from frequent depression and suicidal ideation

Positive Emotions from Brain Injury: The Emergence of Mirth and Happiness. Mario F. Mendez and Leila Parand. Case Reports in Psychiatry, Volume 2020, Article ID 5702578, Jan 29 2020.

Rolf Degen's take:

Abstract: Brain injury can result in an increase in positive emotions. We describe a 63-year-old man who presented with a prominent personality change after a gunshot wound to the head. He became “content,” light-hearted, and prone to joking and punning. Prior to his brain injury, he suffered from frequent depression and suicidal ideation, which subsequently resolved. Examination showed a large right calvarial defect and right facial weakness, along with memory impairment and variable executive functions. Further testing was notable for excellent performance on joke comprehension, good facial emotional recognition, adequate Theory of Mind, and elevated happiness. Neuroimaging revealed loss of much of the right frontal and right anterior lobes and left orbitofrontal injury. This patient, and the literature, suggests that frontal predominant injury can facilitate the emergence of mirth along with a sense of increased happiness possibly from disinhibited activation of the subcortical reward/pleasure centers of the ventral striatal limbic area.

3. Discussion

This patient had a heightened sense of mirth and happiness after his brain injury. The loss of much of his right frontal and right anterior temporal lobes, and damage to left orbitofrontal cortex, altered his personality towards not just silly joking consistent with Witzelsucht but an actual increase in his appreciation of humor. He also maintained a very positive outlook and increased apparent happiness or contentment, per his report. On examination, he was able to detect jokes and identify them as funny, and he consistently described himself as very happy despite his brain injury and situation.

Beyond his joking or “Witzelsucht” from the German words for joke (Witz) and addiction (Sucht) [45], this patient had increased mirth. Mundane experiences and others’ jokes caused him amusement. Investigators have characterized the neurobiology of humor as involving several modular aspect [113]. The first is the cognitive aspect, or getting the joke, namely, the perception of incongruity or of incompatibility between an anticipated perspective and the punchline. Second, with resolution of the incongruity, there is the actual humor appreciation or mirth involving the dopaminergic pleasure/reward centers of the ventral striatum and nucleus accumbens (VS/NA) [1416]. The frontal lobes participate in incongruity detection and resolution, with the left frontal more responsive to simple humor [1618], and the right more engaged with complex humor [141921]. In addition, other regions may contribute to incongruity detection and resolution, such as the temporoparietal junction, the precuneus, the posterior cingulate cortex, and the parahippocampal gyrus [22]. Once incongruity is resolved, the new explanation triggers emotionally pleasurable responses experienced as mirth [914152324]. Since this patient could “get a joke,” his changes appeared at the level of the ease of elicitation of mirth.

The regions associated with the experience of mirth include the VS/NA as well as connections from the anterior cingulate gyrus (ACG), posterior insula, and frontal (left>right) lobe [2528]. Deep brain stimulation of the VS/NA induces mirth and enhances effective connectivity from the ACG to the VS [2526]. As well as promoting surprise, electrical stimulation of the rostral pregenual ACG can also elicit laughter with mirth [272930]. The experience of mirth can occur with the rerepresentation and integration of interoceptive information in the insula [28]. Finally, the frontal lobes trigger humor appreciation through connections with these structures [141620293132].

The formation and regulation of happiness seem to be associated with significant reductions in activity in the right prefrontal cortex, as well as increased activity in the VS/NA [33]. The left frontal lobe may produce a default state biased towards happy or positive interpretations [34]. For example, cortical sites that produce mirth when stimulated tend to be located in the dominant hemisphere close to language areas [3536]. Furthermore, disruption of left frontostriatal emotion regulation systems can impair the ability to suppress positive emotions such as happiness [37]. Together, these findings, as well as the patient’s increased appreciation of humor, suggest that his brain lesion facilitated or released his VS/NA area from any negative input or inhibition. This view must be interpreted cautiously from the analysis of a single patient. There may be other explanations for the patient’s positive emotions, such as the simple relief from depression after his head injury, or as a result of alleviation of stress from no longer functioning as a minister. Nevertheless, his personality change was quite dramatic shortly after recovering from his gunshot wound to the head.

We conclude that positive emotions such as mirth and happiness can emerge from brain lesions and persist. The loss of much of the right frontal and right anterior temporal lobes and damage to the left orbitofrontal cortex facilitated a positive sense of amusement and a positive outlook described as “contentment” by this patient. The literature suggests that this can occur in patients with predominant damage to the right frontal lobe, but also affecting left frontostriatal circuits. These observations warrant further investigation as they speak to the source of positive emotions in humans.

When unethically-earned money is first "laundered" -the cash is physically exchanged for the same amount but from a different arbitrary source- people spent it as if it was earned ethically

 Mental Money Laundering: A Motivated Violation of Fungibility. Alex Imas, George Loewenstein & Carey Morewedge. Carnegie Mellon University Working Paper, September 8 2020.

Abstract: People exploit flexibility in mental accounting to relax psychological constraints on spending. Four studies demonstrate this in the context of moral behavior. The first study replicates prior findings that people donate more money to charity when they earned it through unethical versus ethical means. However, when the unethically-earned money is first "laundered" - the cash is physically exchanged for the same amount but from a different arbitrary source - people spent it as if it was earned ethically. This mental money laundering represents an extreme fungibility violation: exchanging "dirty" money for the same sum coming from a "clean" source significantly changed people's propensity to spend it prosocially. The second study demonstrates that mental money laundering generalizes to cases in which ethically and unethically earned money is mixed. When gains from ethical and unethical sources were pooled, people spent the entire pooled sum as if it was ethically earned. The last two studies provide mixed support for the prediction that people actively seek out laundering opportunities for unethically earned money, suggesting partial sophistication about these effects. These findings provide new evidence for the ease with which people can rationalize misbehavior, and have implications for consumer choice, corporate behavior and public policy.

Why do we have big gluteal muscles?

Why do we have big gluteal muscles? Daniel Kolitz. Gizmodo, September 21, 2020.

Some experts gave their opinion in 2018. Among them, Jason Bourke, Paleontologist and Assistant Professor of Anatomy, New York Institute of Technology College of Osteopathic Medicine at Arkansas State:

The structures we refer to as butt cheeks in humans are comprised of the gluteal muscles: gluteus minimus, gluteus medius, and gluteus maximus. Of the three gluteal muscles, gluteus maximus is responsible for the signature shape of the human derriere. It originates from a line that runs from our upper ilium (the pelvic bone that people often call their hips) down towards our coccyx (tailbone). The muscle attaches close to the top of our femur (thigh bone). The gluteus maximus functions as our major leg extensor and is the main driver of our legs when running, climbing stairs, getting up from a seated position etc. It’s the powerhouse muscle we call upon whenever we need to perform major postural changes, or when we need to move our legs fast. That’s why sprinters, and weightlifters that do heavy-weighted squats tend to have very round and firm buttocks (i.e., “squat butt”).

Because the muscle originates and inserts across a fairly small distance, it needs to produce a lot of force to get our legs to move. This makes the muscle very large, but since there is not a lot of space for the muscle to sit, the muscle fibres expand outwards and – thanks to gravity – downwards resulting in our hallmark hind ends.

The shape of our rear end is practically unique to our species. As we transitioned from quadrupedal apes to bipedal ones, our pelvis underwent radical changes to handle the weight of our entire torso resting on top of it. This required substantial reorientation of many of our hip muscles and it put our major leg extensor (gluteus maximus) in this weird position where it seems to almost hang off of our pelvis. There are a few other species of mammals that have what we might term “butt cheeks”. Namely horses, which show substantial developments of their rear ends as well. As with humans, well-developed gluteal muscles are responsible for the roundness of horse butts. However, unlike humans, horses achieved this shape via expansion of a different gluteal muscle, their gluteus medius. In fact, a large gluteus medius is pretty standard for most mammals. Humans are unique in expanding our gluteus maximus instead, which is no doubt a response to the unique physical demands of our strange way of walking.

Moral Choice When Harming Is Unavoidable

Moral Choice When Harming Is Unavoidable. Jonathan Z. Berman, Daniella Kupor. Psychological Science,  September 8, 2020.

Abstract: Past research suggests that actors often seek to minimize harm at the cost of maximizing social welfare. However, this prior research has confounded a desire to minimize the negative impact caused by one’s actions (harm aversion) with a desire to avoid causing any harm whatsoever (harm avoidance). Across six studies (N = 2,152), we demonstrate that these two motives are distinct. When decision-makers can completely avoid committing a harmful act, they strongly prefer to do so. However, harming cannot always be avoided. Often, decision-makers must choose between committing less harm for less benefit and committing more harm for more benefit. In these cases, harm aversion diminishes substantially, and decision-makers become increasingly willing to commit greater harm to obtain greater benefits. Thus, value trade-offs that decision-makers refuse to accept when it is possible to completely avoid committing harm can suddenly become desirable when some harm must be committed.

Keywords: moral choice, value trade-offs, harm aversion, harm avoidance, protected values, open data, open materials, preregistered

Across six studies, we demonstrated that the preference to avoid inflicting any harm not only is distinct from but also outweighs the preference to minimize its impact. Our results suggest that the manner in which individuals bracket instances of harm affects their willingness to commit harm (cf. Read, Loewenstein, Rabin, Keren, & Laibson, 1999). For instance, individuals may be more reluctant to commit a second violation a month after a first violation than they would be if the second violation occurred just moments after the first. This is because the two harmful actions may be more likely to be bracketed together in the latter case and may thus be perceived as an unavoidable-harm context.

Although we focused our examination on decisions impacting social welfare, similar outcomes may occur for decisions that are exclusively self-relevant. For instance, research suggests that individuals are particularly averse to holding debt if they do not need to be in debt but prefer to take on more debt to maintain their assets if holding debt is unavoidable (Sussman & Shafir, 2012).

Finally, in Study 4, we found that even when greater harm produced diminishing marginal benefits, individuals were still more willing to commit greater harm than when it was possible to commit no harm. However, there is likely a threshold for which committing more harm is no longer perceived as worthwhile. Future research can investigate factors that affect this threshold.

In sum, we found that decision-makers who can completely avoid committing a harmful act frequently choose to do so. However, when committing some harm is unavoidable, decision-makers become increasingly willing to trade off greater harm for greater benefits.