Friday, October 20, 2017

Statistically inaccurate and morally unfair judgements via base rate intrusion

Statistically inaccurate and morally unfair judgements via base rate intrusion. Jack Cao, Max Kleiman-Weiner & Mahzarin R. Banaji. Nature Human Behaviour 1, 738–742 (2017). doi:10.1038/s41562-017-0218-y

Abstract: From a statistical standpoint, judgements about an individual are more accurate if base rates about the individual’s social group are taken into account1,2,3,4. But from a moral standpoint, using these base rates is considered unfair and can even be illegal5,6,7,8,9. Thus, the imperative to be statistically accurate is directly at odds with the imperative to be morally fair. This conflict was resolved by creating tasks in which Bayesian rationality and moral fairness were aligned, thereby allowing social judgements to be both accurate and fair. Despite this alignment, we show that social judgements were inaccurate and unfair. Instead of appropriately setting aside social group differences, participants erroneously relied on them when making judgements about specific individuals. This bias—which we call base rate intrusion—was robust, generalized across various social groups (gender, race, nationality and age), and differed from analogous non-social judgements. Results also demonstrate how social judgements can be corrected to achieve both statistical accuracy and moral fairness. Overall, these data (total N = 5,138) highlight the pernicious effects of social base rates: under conditions that closely approximate those of everyday life10,11,12, these base rates can undermine the rationality and fairness of human judgements.

Foreign-Looking Native-Accented People: More Competent When First Seen Rather Than Heard

Foreign-Looking Native-Accented People: More Competent When First Seen Rather Than Heard. Karolina Hansen, Tamara Rakić and Melanie Steffens. Social Psychological and Personality Science,

Abstract: Psychological research has neglected people whose accent does not match their appearance. Most research on person perception has focused on appearance, overlooking accents that are equally important social cues. If accents were studied, it was often done in isolation (i.e., detached from appearance). We examine how varying accent and appearance information about people affects evaluations. We show that evaluations of expectancy-violating people shift in the direction of the added information. When a job candidate looked foreign, but later spoke with a native accent, his evaluations rose and he was evaluated best of all candidates (Experiment 1a). However, the sequence in which information was presented mattered: When heard first and then seen, his evaluations dropped (Experiment 1b). Findings demonstrate the importance of studying the combination and sequence of different types of information in impression formation. They also allow predicting reactions to ethnically mixed people, who are increasingly present in modern societies.

Sexual objectification decreases women’s experiential consumption (but not material consumption)

Sexual objectification decreases women’s experiential consumption (but not material consumption). Fei Teng, Xue Wang & Ye Yang. Social Influence,

Abstract: The current investigation examined our prediction that sexual objectification decreases women’s experiential consumption but not material consumption. Three experiments provided converging support for this prediction. In particular, female participants reported lower tendency to engage in experiential consumption after recalling a past experience of objectification (Studies 1 and 3) and chose a material product over an experiential one after receiving objectifying comments (Study 2). Furthermore, Study 3 found that sexual objectification reduced purchase inclination of experiential products, and this effect did not emerge for material products. These findings contribute to the literature on sexual objectification by showing the impact of sexual objectification on women’s economic decisions and behaviors.

Keywords: Sexual objectification, experiential consumption, consumer behavior

Origin of the RNA world: The fate of nucleobases in warm little ponds

Origin of the RNA world: The fate of nucleobases in warm little ponds. Ben Pearce et al. Proceedings of the National Academy of Sciences. Published online before print October 2, 2017, doi: 10.1073/pnas.1710339114

Significance: There are currently two competing hypotheses for the site at which an RNA world emerged: hydrothermal vents in the deep ocean and warm little ponds. Because the former lacks wet and dry cycles, which are well known to promote polymerization (in this case, of nucleotides into RNA), we construct a comprehensive model for the origin of RNA in the latter sites. Our model advances the story and timeline of the RNA world by constraining the source of biomolecules, the environmental conditions, the timescales of reaction, and the emergence of first RNA polymers.

Abstract: Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet-dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth's early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of "targets" for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet-dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago.

Motor cortex and volitional control: Ability to suppress undesired movement

Motor cortex — to act or not to act? Christian Laut Ebbesen & Michael Brecht. Nature Reviews Neuroscience 18, 694–705 (2017), doi:10.1038/nrn.2017.119

Abstract: The motor cortex is a large frontal structure in the cerebral cortex of eutherian mammals. A vast array of evidence implicates the motor cortex in the volitional control of motor output, but how does the motor cortex exert this 'control'? Historically, ideas regarding motor cortex function have been shaped by the discovery of cortical 'motor maps' — that is, ordered representations of stimulation-evoked movements in anaesthetized animals. Volitional control, however, entails the initiation of movements and the ability to suppress undesired movements. In this article, we highlight classic and recent findings that emphasize that motor cortex neurons have a role in both processes.

My commentary: Most of the interest in the motor cortex is about movement initiation, forgetting the important issue of control (when to stop, at which distance, etc.). This paper reviews both functions (start and stop).

The highest-earning women's wages are penalized by obesity as much as five times that of the lowest earners

On the Distributional and Evolutionary Nature of the Obesity Wage Penalty. Christian Brown, P. Wesley Routon. Economics & Human Biology,

•    We examine the obesity wage penalty across the wage distribution and career.
•    Quantile and fixed-effect quantile regression control for unobserved heterogeneity.
•    We find an increasingly severe penalty across the wages distribution for women.
•    The obesity wage penalty has grown over time and may slow wage growth.

Abstract: The economics literature supports a link between labor market measures, such as earnings, and health conditions, such as obesity. There is reason to believe the effects of obesity on wages may vary for high- and low-earning individuals and that obesity wage effects may evolve over a lifecycle or from generation to generation. Drawing on data from two longitudinal surveys, we estimate quantile and fixed effect quantile regressions, among others, to further examine the obesity wage effect. Results suggest an increasingly severe penalty across the wage distribution for females. Specifically, the highest-earning women may be penalized as much as five times that of the lowest earners. Results for males suggest that penalties may be present at select wage levels, while prior research has generally found no male obesity penalty. We also provide evidence that the obesity penalty has increased across generations and limited evidence that it may slow earnings growth over one’s lifetime.

JEL: I10; I14; J31
Keywords: Obesity; earnings; wage penalty; longitudinal quantile regression; NLSY79; NLSY97

My commentary: What we imagine is the life of the obese persons? We intuitively believe that getting up in the morning is more slow, that with age the knees will suffer more due to the excessive weight of the body above them, and in some way productivity diminishes.

For those earning less, which are not penalized, the more physical nature of work needs a greater BMI than those of higher earnings.

"Alternatively, individuals with higher BMI may be self-selecting into lower wages by reducing their involvement in the labor market. This is possible if individuals with higher BMIs expect to work less, work for fewer years, or experience attendant health conditions that will limit their ability to work and their employee lifecycle. Further, if higher BMI individuals expect to face discrimination, this may reduce job search time and desire to seek out training, education, and promotion opportunities.

Conversely, obesity penalties are found for the higher key quantiles of the distribution generally associated with more sedentary and competitive forms of work. If BMI is not an important determinant of low wages, and is a major determinant of higher wages, this may suggest that discrimination occurs in the labor market. In an asymmetrical information context, employers discriminate against obese individuals by paying them less or denying opportunities [...] because obesity is seen as an observable proxy for unobservable negative characteristics. It could be that employers are expecting an increased likelihood of healthcare costs and are preemptively selecting obese employees out of employment opportunities which would result in an increasing lifetime earnings profile."