Clustering in globally coupled oscillators

In this paper we describe approaches to clustering in systems of globally coupled identical oscillators. The first of these approaches is based entirely on the symmetry of such systems, and gives information about the behaviour of the systems near degenerate bifurcation points. We summarize existing results from such analysis, and indicate why further techniques are required to augment the symmetry-based methods. This leads to a second approach based on constructing certain reduced models. This modelling approach relies indirectly on symmetry, using the fact that the systems in question have many invariant subspaces as a result of their symmetry. It is shown how knowledge of behaviour on certain subspaces can be used to predict behaviour on others subspaces, even when their dimensions are different. In applications, this approach can be used to predict the stable clustering behaviour that cannot be predicted by other approaches and may be hard to find numerically. All results are illustrated with examples.     

Neural components of social evaluation.

Evaluative responses appear to involve 2 seemingly distinct sets of processes: those that are automatically activated and others that are more consciously controlled. Using functional magnetic resonance imaging, the authors investigated the brain systems associated with automatic and controlled evaluative processing. Participants made either evaluative (good-bad) or nonevaluative (past-present) judgments about famous names. Greater amygdala activity was observed for names rated as "bad" relative to those rated as "good," regardless of whether the task directly involved an evaluative judgment (good-bad) or not (past-present). Good-bad judgments resulted in greater medial and ventrolateral prefrontal cortex (PFC) activity than past-present judgments. Furthermore, there was greater ventrolateral PFC activity in good-bad judgments marked by greater ambivalence. Together, these findings indicate a neural distinction between processes engaged for automatic and controlled evaluation. Whereas automatic processes are sensitive to simple valence, controlled processes are sensitive to attitudinal complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit social cognition: Attitudes, self-esteem, and stereotypes.

Social behavior is ordinarily treated as being under conscious (if not always thoughtful) control. However, considerable evidence now supports the view that social behavior often operates in an implicit or unconscious fashion. The identifying feature of implicit cognition is that past experience influences judgment in a fashion not introspectively known by the actor. The present conclusion--that attitudes, self-esteem, and stereotypes have important implicit modes of operation--extends both the construct validity and predictive usefulness of these major theoretical constructs of social psychology. Methodologically, this review calls for increased use of indirect measures--which are imperative in studies of implicit cognition. The theorized ordinariness of implicit stereotyping is consistent with recent findings of discrimination by people who explicitly disavow prejudice. The finding that implicit cognitive effects are often reduced by focusing judges' attention on their judgment task provides a basis for evaluating applications (such as affirmative action) aimed at reducing such unintended discrimination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Harvesting implicit group attitudes and beliefs from a demonstration web site.

Respondents at an Internet site completed over 600,000 tasks between October 1998 and April 2000 measuring attitudes toward and stereotypes of social groups. Their responses demonstrated, on average, implicit preference for White over Black and young over old and stereotypic: associations linking male terms with science and career and female terms with liberal arts and family. The main purpose was to provide a demonstration site at which respondents could experience their implicit attitudes and stereotypes toward social groups. Nevertheless, the data collected are rich in information regarding the operation of attitudes and stereotypes, most notably the strength of implicit attitudes, the association and dissociation between implicit and explicit attitudes, and the effects of group membership on attitudes and stereotypes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Math = male, me = female, therefore math ≠ me.

College students, especially women, demonstrated negativity toward math and science relative to arts and language on implicit measures. Group membership (being female), group identity (self = female), and gender stereotypes (math = male) were related to attitudes and identification with mathematics. Stronger implicit math = male stereotypes corresponded with more negative implicit and explicit math attitudes for women but more positive attitudes for men. Associating the self with female and math with male made it difficult for women, even women who had selected math-intensive majors, to associate math with the self. These results point to the opportunities and constraints on personal preferences that derive from membership in social groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Judgments of the lucky across development and culture.

For millennia, human beings have believed that it is morally wrong to judge others by the fortuitous or unfortunate events that befall them or by the actions of another person. Rather, an individual's own intended, deliberate actions should be the basis of his or her evaluation, reward, and punishment. In a series of studies, the authors investigated whether such rules guide the judgments of children. The first 3 studies demonstrated that children view lucky others as more likely than unlucky others to perform intentional good actions. Children similarly assess the siblings of lucky others as more likely to perform intentional good actions than the siblings of unlucky others. The next 3 studies demonstrated that children as young as 3 years believe that lucky people are nicer than unlucky people. The final 2 studies found that Japanese children also demonstrate a robust preference for the lucky and their associates. These findings are discussed in relation to M. J. Lerner's (1980) just-world theory and J. Piaget's (1932/1965) immanent-justice research and in relation to the development of intergroup attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A unified theory of implicit attitudes, stereotypes, self-esteem, and self-concept.

This theoretical integration of social psychology's main cognitive and affective constructs was shaped by 3 influences: (a) recent widespread interest in automatic and implicit cognition, (b) development of the Implicit Association Test (IAT; A. G. Greenwald, D. E. McGhee, & J. L. K. Schwartz, 1998), and (c) social psychology's consistency theories of the 1950s, especially F. Heider's (1958) balance theory. The balanced identity design is introduced as a method to test correlational predictions of the theory. Data obtained with this method revealed that predicted consistency patterns were strongly apparent in the data for implicit (IAT) measures but not in those for parallel explicit (self-report) measures, Two additional not-yet-tested predictions of the theory are described. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Implicit gender stereotyping in judgments of fame.

Implicit (unconscious) gender stereotyping in fame judgments was tested with an adaptation of a procedure developed by L. L. Jacoby, C. M. Kelley, J. Brown, and J. Jasechko (1989). In Experiments 1–4, participants pronounced 72 names of famous and nonfamous men and women, and 24 or 48 hr later made fame judgments in response to the 72 familiar and 72 unfamiliar famous and nonfamous names. These first experiments, in which signal detection analysis was used to assess implicit stereotypes, demonstrate that the gender bias (greater assignment of fame to male than female names) was located in the use of a lower criterion (B) for judging fame of familiar male than female names. Experiments 3 and 4 also showed that explicit expressions of sexism or stereotypes were uncorrelated with the observed implicit gender bias in fame judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic and controlled processes in stereotype priming.

The experiments in this article were conducted to observe the automatic activation of gender stereotypes and to assess theoretically specified conditions under which such stereotype priming may be moderated. Across 4 experiments, 3 patterns of data were observed: (1) evidence of stereotype priming under baseline conditions of intention and high cognitive constraints; (2) significant reduction of stereotype priming when a counterstereotype intention was formed even though cognitive constraints were high; and (3) complete reversal of stereotype priming when a counterstereotype intention was formed and cognitive constraints were low. These data support proposals that stereotypes may be automatically activated, as well as proposals that perceivers can control and even eliminate such effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)