Principal Investigator: Erik Parens

Funder: National Human Genome Research Institute

Purpose

Describe for non-experts in behavioral geneticists (1) what behavioral geneticists have—and have not—discovered about the role of genes in the emergence of complex human traits and (2) what light such findings can—and cannot—be expected to shed on fundamental human values like freedom and equality.

Products

E. Parens, “Genetic Differences and Human Identities: On Why Talking about Behavioral Genetics Is Important and Difficult.” A special report in the Hastings Center Report, January-February 2004.

E. Parens, A. Chapman, and N. Press, Wrestling with Behavioral Genetics: Science, Ethics, and Public Conversation (Johns Hopkins University Press, 2006).

C Baker, Behavioral Genetics: An Introduction to How Genes and Environments Interact through Development to Shape Differences in Mood, Personality (AAAS, 2004). (AAAS)

Premises

• Behavioral genetics research aims both at basic understanding of the nature of complex traits like intelligence and mood and ultimately at improving the treatment of diseases like schizophrenia and bipolar disorder.
• Research into the genetic basis of complex traits in the past has been put to hurtful purposes, including efforts to justify social inequalities.
• If our society is to promote the salutary uses and resist the pernicious uses of behavioral genetics, there must be open and informed public conversation about what the scientific findings do—and do not—tell us about behavior and about who we are.

Lessons and Findings

• While the fantasy that single genes determine complex human traits continues to linger in the popular imagination, contemporary behavioral genetics research paints a far more complex picture: complex traits emerge over time out of staggeringly complex interactions among genetic and environmental factors. Indeed, one of the most fascinating discoveries of behavioral genetics in the twenty-first century is that, to understand the role of genes in the emergence of complex traits, one must also understand how environments influence gene expression. In other words, the meager results of studying nature alone led researchers to begin to study in earnest how nature and nurture interact.
• Insofar as behavioral genetics investigates human behavior, some worry that behavioral genetics will reveal that our choices are determined and that freedom is an illusion. Again, however, the research does not paint such a simple picture. Even if one holds a deterministic view of human behavior, behavioral genetics allows that among the “determinants” are words, human relationships, customs, and social institutions.
• Insofar as behavioral genetics investigates how genetic differences influence the emergence of observed differences among human beings, some worry that behavioral genetics will be used to undermine our concept of moral equality. While genetic differences have in principle nothing to do with the moral equality of all persons, our society has a history of misusing information about putative genetic differences to justify inequalities in the distribution of social power. The danger of such misuse appears to be permanent, and so too the need for vigilance. On the other hand, insofar as the behavioral geneticists’ “individual differences” perspective teaches us to expect variation with respect to any complex trait in a population, findings from behavioral genetics could lend themselves to efforts to affirm human variation.
• Giving genes their due—but not more than their due—is now, and for the foreseeable future will be, an ongoing challenge for public conversation.