A Neural Analysis of Intergroup Perception and Evaluation

In an era of increasing globalization, social and economic harmony depends on the ability of people to cooperate with others from a variety of ethnic, geographic, and religious backgrounds. A trend toward explicitly egalitarian attitudes among North Americans has been accompanied (and motivated) by legislation that makes discrimination a crime and public scrutiny that makes a single racist statement a major political liability. Yet, although a majority of Americans now report nonprejudiced attitudes and strong motivations to respond without prejudice, investigations over the past few decades have shown that the majority still have lingering automatic and perhaps unconsciously activated negative responses toward many minorities and socially disadvantaged groups (Nosek, Banaji, & Greenwald, 2002). These subtle prejudices have been shown to activate even among individuals with egalitarian motivations, and appear to take considerable cognitive effort to control once released. These prejudices have also been shown to directly predict discrimination, including negative nonverbal behavior and biased hiring decisions toward racial and other social groups (Dovidio, Kawakami, & Gaertner, 2002; Dovidio, Kawakami, Johnson, Johnson, & Howard, 1997). In a recent meta analysis, these automatic forms of prejudice were stronger predictors of discrimination than self report when there was a strong desire to hide or conceal one ’ s attitude (Greenwald, Poehlman, Uhlmann, & Banaji, in press). To deal with these challenges, basic research is needed to understand the structures and mechanisms that promote social prejudice: from large societal structures and historical events, to the genetic and neural mechanisms that provide the basic machinery humans use to understand and navigate their complex social worlds. Although research examining the neural bases of prejudice using neuroscience methods has a relatively short history, this research has already made dramatic progress. Looking across several key studies, one conclusion can be easily drawn — the processing of social group membership (typically investigated in a racial context) appears to influence nearly all aspects of brain function from early visual processing to higher order aspects of executive function and deliberate thought. The widely distributed patterns of brain activity found to covary with the processing of social groups suggest that the simple categorization of people into groups influences not a single group perception system, but rather a constellation of processes that collectively give rise to a multitude of social biases. Although the processes underlying social perception require further specification, initial neuroscience research on social prejudice provides important hints for our understanding of the mechanisms of prejudice and intergroup discrimination.