War, the great simplifier, is the inevitable enemy of distinctions, especially when conflicts evoke survival fears, sounding echoes from humanity's environment of evolutionary adaptation. Throughout the twentieth century, attackers and targets grew more distant, weaponry grew more destructive, and distinctions — between combatants and civilians, between legitimate and protected targets, between defensive and offensive strategies, between the innocent and the guilty — faded. In the twenty-first century's first major conflict, “the war against terror,” distinctions have faded still further, making nearly indistinguishable the frontier between preemption and prevention and between interrogation and torture. Proclaimed a “new type of war” in which old rules and customary safeguards would often be inapplicable, this conflict quickly came to be characterized by political embarrassment and operational scandal.

Laboratory research studying behavior in the Prisoner's Dilemma (PD) game is consistent with the commonplace perception that social exchange is risky. Although they often do cooperate, people also often defect. Thus, the decision to enter a PD game with a stranger, about whom one has no good basis for predicting behavior, is a bet on cooperation. Many investigators have explored a range of cognitive processes and individual differences putatively bearing on the choice to enter such games, but few have asked how people perceive, assess, and respond to social risk in general. That is what we ask here. From the well known finding that people are risk-averse in the domain of gains and risk-tolerant in the domain of losses, we predict that, with game incentives constant, people will be more willing to enter social relationships when game payoffs are framed as losses than when they are framed as gains. We tested this prediction in a student population playing PD games. Results strongly supported the prediction, suggesting that human sociality may have evolved more as a defensive response to the possibility of loss than as an opportunistic attempt to capture gain.

Political philosophers have doubted the compatibility of various major values, such as equality and freedom. Ethnographic and historical evidence has indicated the presence of (1) economic equality and individual freedom in the absence of civil peace in segmentary societies based on self-help; (2) economic equality and civil peace in the absence of individual freedom in corporate societies; and (3) individual freedom and civil peace in the absence of economic equality in mercantile and capitalist societies. However, little if any evidence has documented all three — economic equality, individual freedom, civil peace — in stable coexistence. By way of delineating the relations between and among the values in question, I offer “The Iron Law of Politics,” which asserts that economic equality, individual freedom, and civil peace cannot all exist simultaneously in any society, although any two of the three can.

Human embryonic stem-cell (hESC) research offers substantial potential benefits but has generated politically influential controversies and, in the United States, funding restrictions. Some observers fear the United States has been falling behind nations more permissive in this field, but policy debate has remained largely anecdotal. This study reports citation data indicating that the share of hESC research publications credited to the United States in the six years following the introduction of key technologies was significantly less than in five less contentious biomedical-research areas. The United States share of hESC publications fell sharply in 2003 and remained near this reduced level in 2004. Putative explanations are reviewed and several implications discussed.

 Background. Citizens of the United States are less likely than are citizens of Europe and several non-European nations to believe that humans evolved from an earlier species. Several theories have been proposed to explain Americans' disbelief in human evolution, but empirical investigation has been sparse.

 Methods. Data on belief in evolution, on scientific knowledge unrelated to evolution, on socioeconomic status, on Christian religiosity, and on political polarity were identified in the General Social Surveys (GSSs) for 1993, 1994, and 2000. These data were then analyzed in bivariate and multivariate tests of theories about evolutionary and anti-evolutionary views.

 Findings. Christian religiosity was the strongest correlate of disbelief in evolution. Low educational attainment was another positive, but weaker, correlate, though disbelief in evolution was not related to general measures of scientific knowledge. Political liberalism and political conservatism predicted evolutionary belief even after controlling for religiosity, education, and other potential confounders. Subcultural differences in belief — those between blacks and whites, rural dwellers and urban dwellers, Southerners and non-Southerners, dogmatists and non-dogmatists — became insignificant under appropriate controls.

 Conclusion. Christian religiosity, especially in a fundamentalist variety, was the primary correlate of disbelief in evolution. Lack of education was an important but lesser factor. Independent of religiosity and education, political conservatism predicted disbelief.