Building on a growing body of research suggesting that political attitudes are part of broader individual and biological orientations, we test whether the detection of the hormone androstenone is predictive of political attitudes. The particular social chemical analyzed in this study is androstenone, a nonandrogenic steroid found in the sweat and saliva of many mammals, including humans. A primary reason for scholarly interest in odor detection is that it varies so dramatically from person to person. Using participants’ self-reported perceptions of androstenone intensity, together with a battery of survey items testing social and political preferences and orientations, this research supports the idea that perceptions of androstenone intensity relate to political orientations—most notably, preferences for social order—lending further support to theories positing the influence of underlying biological traits on sociopolitical attitudes and behaviors.

A recent paper, “Parkinson's disease mild cognitive impairment classifications and neurobehavioral symptoms” (McDermott et al., 2017), provides an interesting comparison of the influence of different criteria for Parkinson's disease with mild cognitive impairment (PD-MCI) on progression to dementia (PDD). Unfortunately, McDermott et al. (2017) incorrectly stated that “only 21% of PD-MCI participants (identified with a 1.5 SD cut-off) converted to PDD within four years” (p.6) in our study (Wood et al., 2016). However, the important point made by Wood et al. (2016) was that the proportion of conversions to PDD was 51% when the PD-MCI diagnosis required a minimum of two 1.5 SD impairments within any single cognitive domain, whereas additional PD-MCI patients classified with one impairment at 1.5 SD in each of the two domains (but never two impairments in the same domain) had a non-significant risk of dementia relative to non-MCI patients (11% vs. 6% converted, respectively). Our PDD conversion rate was 38% when combining both 1.5 SD criteria (21/56 PD-MCI patients vs. 4/65 non-MCI patients converted); McDermott et al. (2017) found a 42% conversion rate over three years for similarly described PD-MCI patients (10/24 PD-MCI patients vs. 0/27 non-MCI patients converted). Our study was also part of a multinational study (n = 467) showing that PD-MCI has predictive validity beyond known demographic and PD-specific factors of influence (Hoogland et al., 2017). All three studies found that multiple cognitive domain impairments are common in PD-MCI. Nonetheless, the research community needs to clarify the association between PD-MCI subtypes and, especially, the optimal cognitive markers for dementia risk in PD patients.

The age and number of important fossil-producing late Pleistocene terraces in the Tunica Hills have recently become quite controversial. One hypothesis holds that only a single loess-mantled Farmdalian terrace flanks the streams in this area. The other maintains that there are two terraces. The youngest is considered essentially Holocene in age while the older is Sangamon in age. Radiometric and stratigraphic evidence collected for this study indicates that there are two terraces. The youngest is late Woodfordian to Holocene in age while the other is Farmdalian.

Duarte et al. are correct that the social science enterprise would improve on several fronts if the number of politically conservative researchers were to increase; however, because they misunderstand the degree to which liberals and conservatives are dispositionally different, they fail to appreciate the full range of reasons that conservatives are reluctant to enter the modern social sciences.

Here we introduce the Genetic and Environmental Foundations of Political and Economic Behaviors: A Panel Study of Twins and Families (PIs Alford, Hatemi, Hibbing, Martin, and Smith). This study was designed to explore the genetic and environmental influences on social, economic, and political behaviors and attitudes. It involves identifying the psychological mechanisms that operate on these traits, the heritability of complex economic and political traits under varying conditions, and specific genetic correlates of attitudes and behaviors. In addition to describing the study, we conduct novel analyses on the data, estimating the heritability of two traits so far unexplored in the extant literature: Machiavellianism and Baron-Cohen's Empathizing Quotient.

Disputes between those holding differing political views are ubiquitous and deep-seated, and they often follow common, recognizable lines. The supporters of tradition and stability, sometimes referred to as conservatives, do battle with the supporters of innovation and reform, sometimes referred to as liberals. Understanding the correlates of those distinct political orientations is probably a prerequisite for managing political disputes, which are a source of social conflict that can lead to frustration and even bloodshed. A rapidly growing body of empirical evidence documents a multitude of ways in which liberals and conservatives differ from each other in purviews of life with little direct connection to politics, from tastes in art to desire for closure and from disgust sensitivity to the tendency to pursue new information, but the central theme of the differences is a matter of debate. In this article, we argue that one organizing element of the many differences between liberals and conservatives is the nature of their physiological and psychological responses to features of the environment that are negative. Compared with liberals, conservatives tend to register greater physiological responses to such stimuli and also to devote more psychological resources to them. Operating from this point of departure, we suggest approaches for refining understanding of the broad relationship between political views and response to the negative. We conclude with a discussion of normative implications, stressing that identifying differences across ideological groups is not tantamount to declaring one ideology superior to another.

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.

The 1980 American national elections produced two highly salient and widely-discussed departures from past tradition. For the first time in forty-eight years, a previously elected incumbent president seeking re-election was defeated. At the same time the Republicans, the traditional minority party, seized control of the upper house. Both events figured heavily in discussions of the American electorate's supposed turn to the right. Much of this emphasis on ideological change may be misplaced. A third, although much less noted, departure from tradition also occurred in 1980: for the first time since 1932, real disposable per capita income declined in the year preceding a presidential election. The importance of such a decline for the electoral fate of an incumbent president has been well documented. Numerous previous studies have indicated a powerful and consistent impact of changes in economic conditions on voting behaviour in presidential elections. The influence of economic conditions on the fate of the president's party in House elections is also well-documented. In the case of Senate elections, however, the literature is curiously silent.

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.

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.

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.

Given all the hype in 1990 about an “anti-incumbent” mood that was supposed to have swept the electorate, it is not too surprising that immediately after the congressional elections of that year most pundits claimed to see clear evidence of this mood in the results. But it is surprising that now, as we approach the next election day, more relaxed and objective analysis has not corrected this erroneous view of what actually transpired in 1990. Thus, before this misconception becomes an indelible part of conventional wisdom, and before the events of 1992, which may include something closer to an authentic anti-incumbent mood, are compared to a mistaken view of the events of 1990, we would like to offer an alternative and, we would argue, more accurate interpretation of the 1990 congressional elections.

November 6, 1990 was to have been the day the fortifications of entrenched incumbents—relentless constituency service, massive warchests, and intimidation of prospective quality challengers—were overwhelmed by the poorly-armed but righteously indignant masses. These masses were incited by brave challengers who concocted clever taunts about the insular and haughty denizens of Washington castle life. These hated insiders, it was said, were surrounded by doting courtiers, undeserved privileges, and unbelievable treasures, and the outsiders were finally going to have their revenge.

With the 1970 passage of the Occupational Safety and Health Act (OSHA), federal regulation reached the American workplace. Given the newness of the legislation, any firm conclusion on its effectiveness seems premature. However, there is ample evidence on federal safety regulation of a specific workplace: the coal mine. The federal government has been directly involved in coal mining safety for over 35 years, operating under three major pieces of legislation, enacted in 1941, 1952, and 1969. Opposing opinions regarding the effect of this legislation can be grouped into three categories: radical, reactionary, and reformer. A multiple interrupted time-series analysis indicates that, in fact, the 1941 and 1969 regulations significantly reduced the fatality rate in coal mining. Certain conditions seem related to the effectiveness of this safety legislation: birth order, provisions, enforcement, target population, and goals. The first two conditions would appear to work for the success of the OSHA, the latter three conditions to work against it.