Socioeconomic Status and Brain

What is socioeconomic status (SES), and why would a cognitive neuroscientist be interested in it?

Volumes have been written about the first question, but for present purposes I will simply say that virtually all societies have better off and less well off citizens, and that differences in material wealth tend to be accompanied by noneconomic characteristics that play an important role in physical and mental development: These include social prestige, educational opportunity and attainment, and control over various aspects of one’s life.  SES refers to this compound of economic and social factors.

The relevance of SES to cognitive neuroscience lies in its surprisingly strong relationship to cognitive ability as measured by IQ and school achievement, beginning in early childhood. Which neurocognitive systems are implicated in these SES gradients in psychological functioning, and what causes the gradients? These are questions for cognitive neuroscience.

Early work from my lab addressed the first question.  By describing the cognitive correlates of childhood SES in terms of a general cognitive neuroscience model of the mind, rather than in terms of standardized test scores, we would then be in a position to bring the explanatory framework of cognitive neuroscience to bear on questions of causality and intervention.  Three studies, undertaken with Kim Noble, Hallam Hurt and others, showed a fairly consistent profile of neurocognitive ability associated with SES in children of different ages (Noble, Norman & Farah, 2005; Farah, et al., 2006; Noble et al., 2007).

Subsequent work has been aimed at understanding the dimensions of childhood experience that cause these differences and the mechanisms by which the differences emerge.  We have found that distinct aspects of early childhood experience (cognitive stimulation and parental nurturance) are predictive of distinct aspects of neurocognitive ability in later childhood (language and memory ability; Farah et al., 2008).  Consistent with these results, and with animal research implicating stress and parenting behavior in hippocampal development, we found that early parental nurturance predicts hippocampal morphology in adolescence (Rao et al., 2010).

Current work, with Daniel Hackman, Gwen Lawson, and others, is aimed at testing the neuroendocrine and structural brain correlates of early experience, including childhood SES and associated differences in cognitive stimulation and parenting (Lawson et al in press). Other labs have begun to apply cognitive neuroscience to the study of SES, there is an emerging literature that offers new clues and constraints for theories of human development in socioeconomic context.  We synthesized this literature in a TiCS review (Hackman  & Farah, 2009).

People of low SES face enormous economic and social barriers to improving their lives.  It is a tragic irony that they so often face this challenge with diminished capabilities as a result of the hardships experienced early in life.  The ultimate goal of this research program is to understand and help break the cycle of poverty using insights from neuroscience.