Political attitudes vary with detection of androstenone.

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.

The genetic and environmental foundations of political, psychological, social, and economic behaviors: a panel study of twins and families.

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.

Liberals and conservatives: Non-convertible currencies.

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.

Nonpolitical images evoke neural predictors of political ideology.

Political ideologies summarize dimensions of life that define how a person organizes their public and private behavior, including their attitudes associated with sex, family, education, and personal autonomy. Despite the abstract nature of such sensibilities, fundamental features of political ideology have been found to be deeply connected to basic biological mechanisms that may serve to defend against environmental challenges like contamination and physical threat. These results invite the provocative claim that neural responses to nonpolitical stimuli (like contaminated food or physical threats) should be highly predictive of abstract political opinions (like attitudes toward gun control and abortion). We applied a machine-learning method to fMRI data to test the hypotheses that brain responses to emotionally evocative images predict individual scores on a standard political ideology assay. Disgusting images, especially those related to animal-reminder disgust (e.g., mutilated body), generate neural responses that are highly predictive of political orientation even though these neural predictors do not agree with participants' conscious rating of the stimuli. Images from other affective categories do not support such predictions. Remarkably, brain responses to a single disgusting stimulus were sufficient to make accurate predictions about an individual subject's political ideology. These results provide strong support for the idea that fundamental neural processing differences that emerge under the challenge of emotionally evocative stimuli may serve to structure political beliefs in ways formerly unappreciated.

Negativity bias and political preferences: a response to commentators.

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.

Differences in negativity bias underlie variations in political ideology.

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.

Cortisol and politics: variance in voting behavior is predicted by baseline cortisol levels.

Participation in electoral politics is affected by a host of social and demographics variables, but there is growing evidence that biological predispositions may also play a role in behavior related to political involvement. We examined the role of individual variation in hypothalamic-pituitary-adrenal (HPA) stress axis parameters in explaining differences in self-reported and actual participation in political activities. Self-reported political activity, religious participation, and verified voting activity in U.S. national elections were collected from 105 participants, who were subsequently exposed to a standardized (nonpolitical) psychosocial stressor. We demonstrated that lower baseline salivary cortisol in the late afternoon was significantly associated with increased actual voting frequency in six national elections, but not with self-reported non-voting political activity. Baseline cortisol predicted significant variation in voting behavior above and beyond variation accounted for by traditional demographic variables (particularly age of participant in our sample). Participation in religious activity was weakly (and negatively) associated with baseline cortisol. Our results suggest that HPA-mediated characteristics of social, cognitive, and emotional processes may exert an influence on a trait as complex as voting behavior, and that cortisol is a better predictor of actual voting behavior, as opposed to self-reported political activity.

Biology, ideology, and epistemology: how do we know political attitudes are inherited and why should we care?

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 sensitivity and the neurophysiology of left-right political orientations.

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.

Effect of benzyl alcohol on recombinant human interleukin-1 receptor antagonist structure and hydrogen-deuterium exchange.

Benzyl alcohol, a preservative commonly added to multidose therapeutic protein formulations, can accelerate aggregation of recombinant human interleukin-1 receptor antagonist (rhIL-1ra). To investigate the interactions between benzyl alcohol and rhIL-1ra, we used nuclear magnetic resonance to observe the effect of benzyl alcohol on the chemical shifts of amide resonances of rhIL-1ra and to measure hydrogen-deuterium exchange rates of individual rhIL-1ra residues. Addition of 0.9% benzyl alcohol caused significant chemical shifts of amide resonances for residues 90-97, suggesting that these solvent-exposed residues participate in the binding of benzyl alcohol. In contrast, little perturbation of exchange rates was observed in the presence of either sucrose or benzyl alcohol.

Political attitudes vary with physiological traits.

Although political views have been thought to arise largely from individuals' experiences, recent research suggests that they may have a biological basis. We present evidence that variations in political attitudes correlate with physiological traits. In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, whereas individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War. Thus, the degree to which individuals are physiologically responsive to threat appears to indicate the degree to which they advocate policies that protect the existing social structure from both external (outgroup) and internal (norm-violator) threats.

Measurement of the second osmotic virial coefficient for protein solutions exhibiting monomer-dimer equilibrium.

The second osmotic virial coefficient (B) is a measure of solution nonideality that is useful for predicting conditions favorable for protein crystallization and for inhibition of aggregation. Static light scattering is the technique most commonly used to determine B values, typically using protein concentrations less than 5 mg/mL. During static light scattering experiments at low protein concentrations, frequently the protein is assumed to exist either as a single nonassociating species or as a combination of assembly states independent of protein concentration. In the work described here, we examined the limit for ignoring weak reversible dimerization (Kd > or =1 mM) by comparing B values calculated with and without accounting for self-association. Light scattering effects for equilibrium dimer systems with Kd <20 mM and Kd <1 mM will significantly affect apparent B values measured for 20 and 150-kDa proteins, respectively. To interpret correctly light scattering data for monomer-dimer equilibrium systems, we use an expanded coefficient model to account for separate monomer-monomer (B(22)), monomer-dimer (B(23)), and dimer-dimer (B(33)) interactions.

High concentration formulations of recombinant human interleukin-1 receptor antagonist: I. Physical characterization.

At relatively high protein concentrations (i.e., up to 100 mg/mL), recombinant human interleukin-1 receptor antagonist (rhIL-1ra) was found to exist in a monomer-dimer equilibrium controlled by solution ionic strength. Sedimentation equilibrium at 25 degrees C was used to measure the increase in the dimer dissociation constant (K(d)) as a function of ionic strength. K(d) increased from 2.0 to 12.6 mM as the solution ionic strength was increased from 0.011 to 0.184 molal. These K(d) values were used with both static light scattering and membrane osmometry data collected over a protein concentration range of 1-100 mg/mL to determine second osmotic virial coefficients. Expanding the second osmotic virial coefficient model to account for separate monomer-monomer (B(22)), monomer-dimer (B(23)), and dimer-dimer (B(33)) interactions reveals net monomer-dimer interactions are attractive, whereas the others are repulsive. Lastly, isothermal titration calorimetry dilution experiments showed that rhIL-1ra dimerization is enthalpically driven (DeltaH(dimerization) << 0), which is consistent with intermolecular cation-pi interactions previously proposed as the monomer-monomer contact sites in dimers.

High concentration formulations of recombinant human interleukin-1 receptor antagonist: II. Aggregation kinetics.

At high protein concentrations (i.e., 50-100 mg/mL) and 37 degrees C, low solution ionic strength accelerates aggregation of recombinant human interleukin-1 receptor antagonist (rhIL-1ra). We have used a variety of physical and spectroscopic techniques to explain this observation. A population balance model was applied to a continuous mixed suspension, mixed product removal (MSMPR) reactor at steady-state to determine aggregate nucleation and growth rates. Nucleation rates increase at low ionic strength, while growth rates are unaffected. At low rhIL-1ra concentrations (i.e., <1 mg/mL), no conformational changes or differences in free energies of unfolding (DeltaG(unf)) were observed at 37 degrees C over the solution ionic strength range of 0.025-0.184 molal used for aggregation studies. However, increasing the protein concentration to 100 mg/mL shifts the rhIL-1ra monomer-dimer equilibrium significantly at low ionic strength to favor dimerization, which is reflected in subtle conformational changes in the circular dichroism and second-derivative FTIR spectra. In addition to a reversible dimer, an irreversible dimer forms by second-order kinetics during incubation at 37 degrees C. This noncovalent dimer does not significantly participate in further aggregation. The loss of native protein due to aggregation at 37 degrees C was third order in protein thermodynamic activity due to the rate-limiting formation of an aggregation-prone trimer. This trimer forms from irreversible attractive monomer-reversible dimer interactions, which were quantified using second osmotic cross virial coefficients. Lastly, the activity coefficient of rhIL-1ra estimated from aggregation rates is 50% higher at 100 mg/mL protein concentration than at 50 mg/mL, in close agreement with predictions from a hard-sphere model for activity coefficients.