Knowledge that Transforms

The threat of being judged stereotypically (stereotype threat) may impair memory performance in older adults, thereby producing inflated age differences in memory tasks. However, the underlying mechanisms of stereotype threat in older adults or other stigmatized groups remain poorly understood. Here, we offer evidence that stereotype threat consumes working memory resources in older adults. More important, using a process-dissociation procedure, we found, for the first time, that stereotype threat undermines the controlled use of memory and simultaneously intensifies automatic response tendencies. These findings indicate that competing models of stereotype threat are actually compatible and offer further reasons for researchers and practitioners to pay special attention to age-related stereotypes during standardized neuropsychological testing.

It has been debated whether human visual working memory is limited by the number of items or the precision with which they are represented. In the research reported here, we show that the precision of working memory can be flexibly and willfully controlled, but only if the number of retained items is low. Electroencephalographic recordings revealed that a neural marker for visual working memory (contralateral delay activity, or CDA) that is known to increase in amplitude with the number of retained items was also affected by the precision with which items were retained. However, willfully enhanced precision increased CDA amplitude only when the number of retained items was low. These results show that both the number and the (willfully controlled) precision of retained items constrain visual working memory: People can enhance the precision of their visual working memory, but only for a few items.

A classic law of cognition is that forgetting curves are closely approximated by power functions. This law describes relations between different empirical dependent variables and the retention interval, and the precise form of the functional relation depends on the scale used to measure each variable. In the research reported here, we conducted a recognition task involving both short- and long-term probes. We discovered that formal memory-strength parameters from an exemplar-recognition model closely followed a power function of the lag between studied items and a test probe. The model accounted for rich sets of response time (RT) data at both individual-subject and individual-lag levels. Because memory strengths were derived from model fits to choices and RTs from individual trials, the psychological power law was independent of the scale used to summarize the forgetting functions. Alternative models that assumed different functional relations or posited a separate fixed-strength working memory store fared considerably worse than the power-law model did in predicting the data.

Research shows that reflecting on benefits received can make people happier, but it is unclear whether or not such reflection makes them more helpful. Receiving benefits can promote prosocial behavior through reciprocity and positive affect, but these effects are often relationship-specific, short-lived, and complicated by ambivalent reactions. We propose that prosocial behavior is more likely when people reflect on being a benefactor to others, rather than a beneficiary. The experience of giving benefits may encourage prosocial behavior by increasing the salience and strength of one's identity as a capable, caring contributor. In field and laboratory experiments, we found that participants who reflected about giving benefits voluntarily contributed more time to their university, and were more likely to donate money to natural-disaster victims, than were participants who reflected about receiving benefits. When it comes to reflection, giving may be more powerful than receiving as a driver of prosocial behavior.

Throughout vertebrate phylogeny, testosterone has motivated animals to obtain and maintain social dominance-a fact suggesting that unconscious primordial brain mechanisms are involved in social dominance. In humans, however, the prevailing view is that the neocortex is in control of primordial drives, and testosterone is thought to promote social dominance via conscious feelings of superiority, indefatigability, strength, and anger. Here we show that testosterone administration in humans prolongs dominant staring into the eyes of threatening faces that are viewed outside of awareness, without affecting consciously experienced feelings. These findings reveal that testosterone motivates social dominance in humans in much the same ways that it does in other vertebrates: involuntarily, automatically, and unconsciously.

The merging of psychological and genetic methodologies has led to an increasing appreciation of environmental moderators of the relationships between genotype and phenotype. Here we used a nonhuman-primate model to study the moderating effect of the mother's genotype on the association of a dopamine D4 receptor (DRD4) gene polymorphism with juvenile impulsivity, assessed in a standardized social-challenge test. The results showed that juvenile carriers of the rare 5-repeat variant of the exon III 48-base-pair repeat polymorphism scored significantly higher in social impulsivity than juveniles homozygous for the common 6-repeat allele. In addition, juvenile genotype interacted with maternal genotype to influence impulsivity, with the highest rates of impulsivity found in variant offspring with variant mothers. These results highlight the importance of considering the genotype of the parents in studies of early experience and vulnerability genes for impulsivity-related traits.

Atheists have long been distrusted, in part because they do not believe that a watchful, judging god monitors their behavior. However, in many parts of the world, secular institutions such as police, judges, and courts are also potent sources of social monitoring that encourage prosocial behavior. Reminders of such secular authority could therefore reduce believers' distrust of atheists. In our experiments, participants who watched a video about police effectiveness (Experiment 1) or were subtly primed with secular-authority concepts (Experiments 2-3) expressed less distrust of atheists than did participants who watched a control video or were not primed, respectively. We tested three distinct alternative explanations for these findings. Compared with control participants, participants primed with secular-authority concepts did not exhibit reduced general prejudice against out-groups (Experiment 1), prejudice reactions associated with functional threats that particular out-groups are perceived to pose (specifically, viewing gays with disgust; Experiment 2), or general distrust of out-groups (Experiment 3). These findings contribute to theory regarding both the psychological bases of prejudices and the psychological functions served by gods and governments.

That similar words can prime one another is not news. However, this phenomenon can be exploited to make inferences about the organization of conceptual representations. What types of similarity matter? Although there is evidence that similarity of function, shape, and even manner of manipulation is reflected in semantic memory, evidence for organization on the basis of color similarity is sparse. This lack of evidence is surprising: Intuition suggests that color is a prominent feature of many object concepts. The research reported here clarifies this puzzle and illustrates the dynamic nature of conceptual representations. Our research demonstrates color-based priming (e.g., "emerald" primes "cucumber") in participants who completed a Stroop color-naming task before a priming task. Notably, the size of the Stroop effect predicted the size of the priming effect. When the order of tasks was reversed, priming effects were eliminated. By demonstrating that both extrinsic and intrinsic factors can influence conceptual activation, our findings have implications for theories of semantic memory.

We predicted that performing movements during art perception that resemble the movements of the artist when creating the artwork would enhance aesthetic appreciation. We used painting style as a subtle manipulation of the artists’ original movements during art creation, while matching depicted content and art period across styles. Participants evaluated neoimpressionistic paintings featuring either a hatching-style or a pointillism-style while performing either tipping or hatching-like hand movements. Although participants did not see their own hand movements and were unaware of the link between painting style and hand movements, tipping participants preferred pointillism-style over hatching-style, while hatching participants preferred hatching-style over pointillism-style. Thus, painting style as a static materialization of the painter’s movements can link the original act of art creation with the moment of art perception.