Soci326-002 – Evolutionary Sociology

Module 7 – Biology of Behavior – Human Diversity II – Discussion Topics – 4 Oct 2005

Today's readings cover

• Rowe.  Limits of Family Influence.
  • Chapter 4 - Limited Rearing Effects on Intelligence (IQ) - Pp. 97-131
  • Chapter 5 - Uniting Nature and Nurture: The Genetics of Environmental Measures - Pp. 132-167
  • Chapter 6 - Gender Differences - Pp. 168-192
  • Chapter 7 - Why Families Have Little Influence - Pp. 193-227

This is the second module concerned with the biological basis of human differences, as distinct from general features of human nature (i.e., our "common genetic heritage" in Lenski's terminology).

Here are some topics for discussion.

1.  Psychologist Steven Ceci may be the leading proponent of the theory that schooling is the main cause of IQ differences in the population (rather than IQ differences causing differences in school success).  Let's discuss the following points:

• Irrespective of whether Ceci's theory is correct or not, in what ways might it attractive (or not) from a philosophical / political / policy-oriented point of view?  (Note: the authors of Inequality by Design (Fischer et al. 1996), a critique of The Bell Curve, rely on Ceci's discussion in attacking Herrnstein and Murray's thesis that cognitive ability has a substantial impact on educational attainment.)
• What is the evidence in favor of a major role of schooling in determining IQ scores?
• Are there empirical difficulties with Ceci's theory that schooling causes intelligence (as measured by IQ tests)?

2.  Today mainstream psychology seems to have accepted the Turkheimer's Three Laws concerning the genesis of intellectual differences among people (as measured by IQ tests), i.e. about half of the IQ variance is genetic, about half is due to the unshared (unique) rearing environment, and a small proportion (declining to zero in late adolescence and adulthood) is due to the shared rearing environment.  How will this emerging consensus affect public policy?  Will the discovery that cognitive ability is substantially genetic undermine efforts to improve public education?  In an influential article econometrician Arthur Goldberger (1979), a critic of behavior genetics, expresses his concern that a finding of high heritability of IQ would make inequality of school outcomes appear "natural, just, and immutable" (p. 327) and could be used to justify opposition to efforts at improving school performance.  Thus he denies the scientific utility of research into the genetic aspects of educational and occupational achievement.  He writes "...[H]eritability estimates serve no worthwhile purpose. ...[O]ne might recognize that estimates are being put to just one use (however unintended and however unjustified), namely to discourage active socioeconomic policy by 'demonstrating scientifically' that current inequalities are the inevitable dictates of nature.  If so ... it may be a good idea to abandon the entire enterprise of estimating genetic variance components of socioeconomic achievement." (p. 346).  Is Goldberger right?  How likely is it today that researchers will abide by Goldberger's suggestion and abandon behavior genetic research on cognitive ability?

3.  Rowe's (1994) last chapter is entitled Why Families Have Little Influence?  What general evolutionary argument might explain why families have little influence?  What are the roles of different learning modes such as horizontal, oblique, or reverse-vertical learning in cultural transmission.  What role does the Hawk and Dove contest model play in explaining the evolution of human heterogeneity in aggressive behavior?  Why is the evolutionary mechanism behind the Hawk and Dove contest called "density-dependent selection"?  Why does Rowe calls for theories of coevolution of genes and culture?

Last modified 11 Oct 2005