Knowledge that Transforms

How fast does the human visual system discriminate individual faces? To address this question, we used a continuous-stimulation paradigm in which event-related potentials (ERPs) to a face stimulus are recorded with respect to another face stimulus, rather than to a preceding blank-screen baseline epoch. Following the shift between two face stimuli, posterior sites showed an early negative ERP deflection that started at 130 ms and peaked at 160 ms, the latency of the N170, an ERP component associated with discriminating faces from objects. The ERP we recorded was larger in amplitude when the preceding stimulus was perceived as a different individual face rather than the same individual face, although face pairs were of equal physical distance in the two conditions. These findings provide direct evidence that individual face discrimination in humans can take place as early as 130 ms following stimulus onset, during the same time window as face detection.

Two studies examined whether chronic and situational expectations about being stigmatized predict attention toward cues that are threatening to social identity. In Study 1, women's chronic expectations about experiencing sexism were positively associated with their attention toward subliminal cues threatening to their social identity. In Study 2, women were vigilant toward subliminal cues threatening to their social identity when the experimental situation conveyed that their gender was devalued, but not when the experimental situation promoted value and respect for their gender. Women were vigilant toward consciously presented cues threatening to their social identity regardless of the attitudes the experimental context conveyed toward their group. These studies have important theoretical and practical implications for understanding the psychological experience of possessing a devalued social identity.

One hypothesis to explain variation in vocal communication in animal species is that the complexity of the social group influences the group's vocal complexity. This social-complexity hypothesis for communication is also central to recent arguments regarding the origins of human language, but experimental tests of the hypothesis are lacking. This study investigated whether group size, a fundamental component of social complexity, influences the complexity of a call functioning in the social organization of Carolina chickadees, Poecile carolinensis. In unmanipulated field settings, calls of individuals in larger groups had greater complexity (more information) than calls of individuals in smaller groups. In aviary settings manipulating group size, individuals in larger groups used calls with greater complexity than individuals in smaller groups. These results indicate that social complexity can influence communicative complexity in this species.

Gaze direction is an important social signal in humans and other primates. In this study, we used an adaptation paradigm to investigate the functional organization of gaze perception in humans. Adaptation to consistent leftward or rightward gaze produced a powerful illusion that virtually eliminated observers' perception of gaze in the adapted direction; gaze to that side was seen as pointing straight ahead, though perception of gaze to the opposite side was unimpaired. This striking dissociation held even when retinotopic mapping between adaptation and test stimuli was disrupted by changes in size or head orientation, suggesting that our findings do not reflect adaptation to low-level visual properties. Moreover, adaptation to averted gaze did not affect judgments of line bisection, illustrating that our findings do not reflect a general spatial bias. Our findings provide evidence that humans have distinct populations of neurons that are selectively responsive to particular directions of seen gaze.

Research has found that narcissists behave aggressively when they receive a blow to their ego. The current studies examined whether narcissistic aggression could be reduced by inducing a unit relation between the target of aggression and the aggressor. Experimental participants were told that they shared either a birthday (Study 1) or a fingerprint type (Study 2) with a partner. Control participants were not given any information indicating similarity to their partner. Before aggression was measured, the partners criticized essays written by the participants. Aggression was measured by allowing participants to give their partner loud blasts of noise through a pair of headphones. In the control groups, narcissists were especially aggressive toward their partner. However, narcissistic aggression was completely attenuated, even under ego threat, when participants believed they shared a key similarity with their partner.

Preferences for mates that possess genes dissimilar to one's own at the major histocompatibility complex (MHC), a polymorphic group of loci associated with the immune system, have been found in mice, birds, fish, and humans. These preferences may help individuals choose genetically compatible mates and may adaptively function to prevent inbreeding or to increase heterozygosity and thereby immunocompetence of offspring. MHC-dissimilar mate preferences may influence the psychology of sexual attraction. We investigated whether MHC similarity among romantically involved couples (N= 48) predicted aspects of their sexual relationship. All women in our sample normally ovulated, and alleles at three MHC loci were typed for each person. As the proportion of MHC alleles couples shared increased, women's sexual responsivity to their partners decreased, their number of extrapair sexual partners increased, and their attraction to men other than their primary partners increased, particularly during the fertile phase of their cycles.

Past research using a variety of methods has suggested that the frontal cortex is asymmetrically involved in the experience and expression of positive (or approach motivational) and negative (or withdrawal motivational) affects, with the left frontal region being involved in positive affects (or approach) and the right frontal region being involved in negative affects (or withdrawal). However, some studies have failed to replicate these effects, leaving many scientists questioning the meaning of the past supportive findings. To examine these inconsistencies in results, we tested the hypothesis that increasing the personal relevance of the stimuli and approach motivational intensity would increase relative left frontal activation. Results supported the predictions. Moreover, by showing the predicted effects with anger-inducing stimuli, the results demonstrated that motivational direction, rather than affective valence, accounts for asymmetrical frontal cortical activity.

Talent-search participants (286 males, 94 females) scoring in the top 0.01% on cognitive-ability measures were identified before age 13 and tracked over 20 years. Their creative, occupational, and life accomplishments are compared with those of graduate students (299 males, 287 females) enrolled in top-ranked U.S. mathematics, engineering, and physical science programs in 1992 and tracked over 10 years. By their mid-30s, the two groups achieved comparable and exceptional success (e.g., securing top tenure-track positions) and reported high and commensurate career and life satisfaction. College entrance exams administered to intellectually precocious youth uncover extraordinary potential for careers requiring creativity and scientific and technological innovation in the information age.

Two studies examined how Olympic performance is explained in American and Japanese contexts. Study 1, an analysis of media coverage of the 2000 and 2002 Olympics, shows that in both Japanese and American contexts, performance is construed mainly in terms of the actions of persons. However, Japanese and American accounts differ in their explanations of the nature and source of intentional agency, that is, in their models of agency. In Japanese contexts, agency is construed as conjoint and simultaneously implicates athletes' personal attributes (both positive and negative), background, and social and emotional experience. In American contexts, agency is construed as disjoint, separate from athletes' background or social and emotional experience; performance is explained primarily through positive personal characteristics and features of the competition. Study 2, in which participants chose information to be included in an athlete's description, confirms these findings. Differences in the construction of agency are reflected in and fostered by common cultural products (e.g., television accounts).

People can generate the same thoughts or process the same information with different degrees of ease, and this subjective experience has implications for attitudes and social judgment. In prior research, it has generally been assumed that the experience of ease or fluency is interpreted by people as something good. In the two experiments reported here, the meaning or value of ease was directly manipulated, and the implications for evaluative judgments were explored. Across experiments, we replicated the traditional ease-of-retrieval effect (more thought-congruent attitudes when thoughts were easy rather than difficult to generate) when ease was described as positive, but we reversed this effect when ease was described as negative. These findings suggest that it is important to consider both the content of metacognition (e.g., "those thoughts were easy to generate") and the value associated with that content (e.g., "ease is good" or "ease is bad").