that persist through the life cycle. For example, children from lower-status social groups tend to be tracked into less demanding academic classes and to be taught to follow directions unquestioningly rather than to exercise critical thinking faculties (e.g., Anyon, 1980; Giroux, 1981; Sieber, 1982; Oakes, 1985). If children actually learn these lessons, there may be specific long-term effects on their ways of thinking. Similarly, there is evidence to suggest that race differences in biological markers are mediated by life experiences that cause lasting physiological stress responses (Clark et al., 1999). Such differences need to be traced in time from the younger ages, where they have usually been studied, into older age.
It is important to avoid the temptation to interpret group differences in cognitive functioning, particularly between social groups of unequal status, as reflecting underlying biological capabilities rather than responses to unequal opportunity or different life conditions (see Cauce et al., 1998). Considerable analysis is usually necessary to arrive at an appropriate explanation. One problem is that some of the usual statistical assumptions underlying between-group comparisons are not met for certain intergroup comparisons (e.g., there is more variance in the cognitive scores of blacks than whites; House et al., 1990, 1994). Another is that particular cognitive measures may not be equally reliable or valid in different cultural/ethnic groups: if an item is not equally familiar across groups, responding may require different amounts of mental effort (e.g., Cauce et al., 1998). Intergroup differences in measures of crystallized abilities may not reflect underlying biological differences because these abilities may be strongly influenced by culture (Cattell, 1963). And, as already noted, intervening variables such as education may not be the same for all groups being compared. Thus, some investigators have argued that an accurate understanding of the meaning of intergroup differences cannot be attained without careful analysis of within-group variation, especially among minority groups (e.g, Markides et al., 1990; Whitfield and Baker-Thomas, 1999). Group labels (race, ethnicity, etc.) are no more than proxies for underlying psychological variables—a useful place to begin research, but not very meaningful until the mechanisms are traced that link observed cognitive differences to causative factors that connect them to group membership.
Understanding the cognitive effects of culturally shared values, beliefs, and practices. This research should describe the relevant values and beliefs (e.g., those concerning age, self, health, relationships, spirituality, technology) and the relevant cultural practices (e.g., communication, health, and everyday activities). It should identify the ways in which these values, beliefs, and practices affect cognitive functioning (including attention, reasoning, memory, and language) and the ways in which cognitive functioning shapes these contexts.