John R. Alford

A broad, multidisciplinary empirical literature reports that individual-level differences in psychology and biology map onto variation in political orientation. In our target article we argued that negativity bias can explain a surprisingly large share of these findings. The commentators generally support the negativity bias hypothesis but suggest theoretical and empirical revisions and refinements. In this response, we organize these proposals, suggestions, and criticisms into four thematic categories and assess their potential for furthering theories and empirical investigations of the bases for individual-variation in political ideology.

Beckwith and Morris raise concerns about the value of twin studies for understanding the role of genetics in complex human behavior, but virtually all of their concerns have been raised and rebutted before. When it comes to the equal environments assumption (EEA), the best approach is to test for and control possible violations of the EEA on heritability estimates rather than merely rejecting all empirical evidence because of the possibility of EEA violations. In many respects, since the study of the genetic basis of complex human behaviors now includes many methods in addition to twin studies, Beckwith and Morris's critique applies more to the behavioral genetics of a quarter century ago than to today's multifaceted behavioral genetics. Twin studies establish that there is a sizeable genetic component to political orientations, thereby giving cause to look further at the nature of that role by using other methodologies, including molecular genetics. We conclude by pointing out that the normative implications of the relevance of genes to human behavior are not nearly as worrisome as Beckwith and Morris seem to believe.

In the past, most political scientists have been oblivious to the growing empirical evidence challenging environmental determinism. Professor Charney, apparently as a result of the fact that genes and the environment interact in a complex fashion, advocates that this passive unawareness be replaced by active denial. Science, however, does not advance by avoiding important relationships merely because they are complicated and, fortunately, science is not heeding Charney's ideologically-based fears. Molecular geneticists, often working in tandem with political scientists, are quickly moving beyond twin studies to identify the specific suites of genes and biological systems that predict variation in core political preferences, whatever labels those preferences might be given in a particular culture at a particular time. We sympathize with the fact that our empirical findings, like those of so many behavioral geneticists, make Charney uncomfortable; still, his critique serves up nothing new—empirically or otherwise. Just as analyses of the roots of sexual preferences cannot presumptively ignore genetics, neither can analyses of the roots of political preferences.

In this article we propose that evolutionary biology can supply political science with a theory of the ultimate causes of human preferences and behaviors that it otherwise lacks. For the most part, political scientists are either unfamiliar with the social side of evolutionary theory or misidentify its key features. Far from being genetically deterministic or leading exclusively to predictions that all human behavior will be selfish, modern evolutionary theories stress that adaptive behavior is frequently characterized by a guarded sort of cooperation. We describe modern biological theory, offer our own version of it, discuss new and potentially useful interpretations of political attitudes and public policies, and present scientific evidence, drawn from research on autistic individuals and monozygotic and dizygotic twins, of the startlingly important role genetics plays in shaping politically relevant attitudes and behaviors.The authors are grateful to Chris Larimer, Levente Littvay, David Rapkin, Kevin Smith, Jeff Spinner-Halev, Elizabeth Theiss-Morse, and anonymous reviewers for their helpful comments and suggestions.