Knowledge that Transforms

Infants engage in an extraordinary amount of learning during their waking hours even though much of their day is consumed by sleep. What role does sleep play in infant learning? Fifteen-month-olds were familiarized with an artificial language 4 hr prior to a lab visit. Learning the language involved relating initial and final words in auditory strings by remembering the exact word dependencies or by remembering an abstract relation between initial and final words. One group napped during the interval between familiarization and test. Another group did not nap. Infants who napped appeared to remember a more abstract relation, one they could apply to stimuli that were similar but not identical to those from familiarization. Infants who did not nap showed a memory effect. Naps appear to promote a qualitative change in memory, one involving greater flexibility in learning.

How is information about people conveyed through their preferences for certain kinds of music? Here we show that individuals use their music preferences to communicate information about their personalities to observers, and that observers can use such information to form impressions of others. Study 1 revealed that music was the most common topic in conversations among strangers given the task of getting acquainted. Why was talk about music so prevalent? Study 2 showed that (a) observers were able to form consensual and accurate impressions on the basis of targets' music preferences, (b) music preferences were related to targets' personalities, (c) the specific cues that observers used tended to be the ones that were valid, and (d) music preferences reveal information that is different from that obtained in other zero-acquaintance contexts. Discussion focuses on the mechanisms that may underlie the links between personality and music preferences.

This research examined whether stigma diminishes people's ability to control their behaviors. Because coping with stigma requires self-regulation, and self-regulation is a limited-capacity resource, we predicted that individuals belonging to stigmatized groups are less able to regulate their own behavior when they become conscious of their stigmatizing status or enter threatening environments. Study 1 uncovered a correlation between stigma sensitivity and self-regulation; the more Black college students were sensitive to prejudice, the less self-control they reported having. By experimentally activating stigma, Studies 2 and 3 provided causal evidence for stigma's ego-depleting qualities: When their stigma was activated, stigmatized participants (Black students and females) showed impaired self-control in two very different domains (attentional and physical self-regulation). These results suggest that (a) stigma is ego depleting and (b) coping with it can weaken the ability to control and regulate one's behaviors in domains unrelated to the stigma.

Students' perceptions of their safety and vulnerability were investigated in 11 public middle schools (more than 70 sixth-grade classrooms) that varied in ethnic diversity. Results of hierarchical linear modeling analyses indicate that higher classroom diversity is associated with feelings of safety and social satisfaction. African American (n= 511) and Latino (n= 910) students felt safer in school, were less harassed by peers, felt less lonely, and had higher self-worth the more ethnically diverse their classrooms were, even when controlling for classroom differences in academic engagement. Results at the school level were similar to those at the classroom level; higher ethnic diversity was associated with lower levels of self-reported vulnerability (but no difference in self-worth) in both fall and spring of sixth grade. In the spirit of Brown v. Board of Education, the current findings offer new empirical evidence for the psychological benefits of multiethnic schools.

The amount of money a person was willing to forgo in order to give 75 dollars to another person decreased as a hyperbolic function of the perceived social distance between them. Similar hyperbolic functions have previously been shown to describe both time and probability discounting.

The relation between social anxiety and hedonic activity remains poorly understood. From a self-regulatory perspective, we hypothesized that socially anxious individuals experience diminished positive experiences and events on days when they are unable to manage socially anxious feelings adequately. In this 21-day experience-sampling study, we constructed daily measures of social anxiety and emotion regulation. Greater dispositional social anxiety was associated with less positive affect and fewer positive events in everyday life. Among individuals defined as socially anxious from their scores on a global self-report measure of social anxiety, the number of positive events was lowest on days when they both were more socially anxious and tended to suppress emotions and highest on days when they were less socially anxious and more accepting of emotional experiences. Irrespective of dispositional social anxiety, participants reported the most intense positive emotions on the days when they were both least socially anxious and most accepting of emotional experiences. Possible clinical implications are discussed.

Word frequency is an important predictor of word-naming and lexical decision times. It is, however, confounded with contextual diversity, the number of contexts in which a word has been seen. In a study using a normative, corpus-based measure of contextual diversity, word-frequency effects were eliminated when effects of contextual diversity were taken into account (but not vice versa) across three naming and three lexical decision data sets; the same pattern of results was obtained regardless of which of three corpora was used to derive the frequency and contextual-diversity values. The results are incompatible with existing models of visual word recognition, which attribute frequency effects directly to frequency, and are particularly problematic for accounts in which frequency effects reflect learning. We argue that the results reflect the importance of likely need in memory processes, and that the continuity between reading and memory suggests using principles from memory research to inform theories of reading.

Should people be considered organ donors after their death unless they request not to be, or should they not be considered donors unless they request to be? Because people tend to stay with the default in a variety of domains, policymakers' choice of default has large and often important effects. In the United States, where the organ-donation policy default is "not a donor," about 5,000 people die every year because there are too few donors. Four experiments examined two domains-being an organ donor and saving for retirement-where default effects occur and have important implications. The results indicate that default effects occur in part because policymakers' attitudes can be revealed through their choice of default, and people perceive the default as indicating the recommended course of action. Policymakers need to be aware of the implicit messages conveyed by their choice of default.

Human reasoning has been characterized as an interplay between an automatic belief-based system and a demanding logic-based reasoning system. The present study tested a fundamental claim about the nature of individual differences in reasoning and the processing demands of both systems. Participants varying in working memory capacity performed a reasoning task while their executive resources were burdened with a secondary task. Results were consistent with the dual-process claim: The executive burden hampered correct reasoning when the believability of a conclusion conflicted with its logical validity, but not when beliefs cued the correct response. However, although participants with high working memory spans performed better than those with lower spans in cases of a conflict, all reasoners showed similar effects of load. The findings support the idea that there are two reasoning systems with differential processing demands, but constitute evidence against qualitative individual differences in the human reasoning machinery.