John R. Alford

This article reports results from the first twin study of adults in the United States that focuses exclusively and comprehensively on political traits. These data allow us to test whether a common set of genetic and environmental influences act upon a broad variety of values, personality traits, and political attitudes. In short, it allows us to empirically investigate whether there are a core set of predispositions that form the basis of our political orientations and, if so, whether these predispositions are shaped by the same environmental and innate forces. The key finding from our analysis is that there are core political predispositions that are rooted in common genetic and environmental influences and that these predispositions are empirically distinct from broader personality traits.

Evidence that political attitudes and behavior are in part biologically and even genetically instantiated is much discussed in political science of late. Yet the classic twin design, a primary source of evidence on this matter, has been criticized for being biased toward finding genetic influence. In this article, we employ a new data source to test empirically the alternative, exclusively environmental, explanations for ideological similarities between twins. We find little support for these explanations and argue that even if we treat them as wholly correct, they provide reasons for political science to pay more rather than less attention to the biological basis of attitudes and behaviors. Our analysis suggests that the mainstream socialization paradigm for explaining attitudes and behaviors is not necessarily incorrect but is substantively incomplete.

Disgust has been described as the most primitive and central of emotions. Thus, it is not surprising that it shapes behaviors in a variety of organisms and in a variety of contexts—including homo sapien politics. People who believe they would be bothered by a range of hypothetical disgusting situations display an increased likelihood of displaying right-of-center rather than left-of-center political orientations. Given its primal nature and essential value in avoiding pathogens disgust likely has an effect even without registering in conscious beliefs. In this article, we demonstrate that individuals with marked involuntary physiological responses to disgusting images, such as of a man eating a large mouthful of writhing worms, are more likely to self-identify as conservative and, especially, to oppose gay marriage than are individuals with more muted physiological responses to the same images. This relationship holds even when controlling for the degree to which respondents believe themselves to be disgust sensitive and suggests that people's physiological predispositions help to shape their political orientations.

Recent research has found a surprising degree of homogeneity in the personal political communication network of individuals but this work has focused largely on the tendency to sort into likeminded...

In this paper, we trace the route by which genetics could ultimately connect to issue attitudes and suggest that central to this connection are chronic dispositional preferences for mass‐scale social rules, order, and conduct—what we label political ideology. The need to resolve bedrock social dilemmas concerning such matters as leadership style, protection from outgroups, and the degree to which norms of conduct are malleable, is present in any large‐scale social unit at any time. This universality is important in that it leaves open the possibility that genetics could influence stances on issues of the day. Here, we measure orientation to these bedrock principles in two ways—a survey of conscious, self‐reported positions and an implicit association test (IAT) of latent orientations toward fixed or flexible rules of social conduct. In an initial test, both measures were predictive of stances on issues of the day as well as of ideological self‐labeling, thereby suggesting that the heritability of specific issue attitudes could be the result of the heritability of general orientations toward bedrock principles of mass‐scale group life.

Variance components estimates of political and social attitudes suggest a substantial level of genetic influence, but the results have been challenged because they rely on data from twins only. In this analysis, we include responses from parents and nontwin full siblings of twins, account for measurement error by using a panel design, and estimate genetic and environmental variance by maximum‐likelihood structural equation modeling. By doing so, we address the central concerns of critics, including that the twin‐only design offers no verification of either the equal environments or random mating assumptions. Moving beyond the twin‐only design leads to the conclusion that for most political and social attitudes, genetic influences account for an even greater proportion of individual differences than reported by studies using more limited data and more elementary estimation techniques. These findings make it increasingly difficult to deny that—however indirectly—genetics plays a role in the formation of political and social attitudes.

Political science traditionally has either ignored biology in favor of purely environmental explanations for political phenomena or merely ruminated about the likely role of biology, leaving data-based research on biopolitics in dangerously short supply. Currently, attention to the apparent genetic basis for political and social orientations holds the greatest promise of advancing empirical biopolitics. Thus, in this essay, we orient behavior genetics research in the larger framework of biology and politics, confront its normative implications, describe the techniques involved, assess the strengths and weaknesses of commonly employed data and procedures, and describe the next steps in this research stream. Because these next steps involve molecular genetic work, we provide some background genetic information, but we mainly urge political scientists to join interdisciplinary teams so that nature and nurture can both be employed in ongoing efforts to understand the sources of mass-scale human politics.

We test the possibility that political attitudes and behaviors are the result of both environmental and genetic factors. Employing standard methodological approaches in behavioral genetics—specifically, comparisons of the differential correlations of the attitudes of monozygotic twins and dizygotic twins—we analyze data drawn from a large sample of twins in the United States, supplemented with findings from twins in Australia. The results indicate that genetics plays an important role in shaping political attitudes and ideologies but a more modest role in forming party identification; as such, they call for finer distinctions in theorizing about the sources of political attitudes. We conclude by urging political scientists to incorporate genetic influences, specifically interactions between genetic heritability and social environment, into models of political attitude formation.

Why are people more willing to accept some governmental decisions than others? In this article, we present results from a series of original experiments showing that people's reactions to a given outcome are heavily influenced by the procedure employed to produce the outcome. We find that subjects react much less favorably when a decision maker intentionally keeps a large payoff, thereby leaving the subject with a small payoff, than when that same payoff results from a procedure based on chance or on desert. Moreover, subjects react less favorably to outcomes rendered by decision makers who want to be decision makers than they do to identical outcomes selected by reluctant decision makers. Our results are consistent with increasingly prominent theories of behavior emphasizing people's aversion to being played for a “sucker,” an attitude that makes perfect sense if people's main goal is not to acquire as many tangible goods as possible but to make sure they are a valued part of a viable group composed of cooperative individuals.