Frank Sulloway (1996) has stirred up great debate with his thesis that birth order explains and predicts people's proclivity to rebel. Scientists, scholars, business writers, and the broad reading and talk-television public alike all have weighed in to discuss the value and veridicality of Sulloway's thesis. Though many think he may be on to something, certain voices—Frederic Townsend's included—argue that his opus is simply bunk.

The response by Somit and Peterson to my earlier commentary in this journal (Corning, 2000), which sharply criticized their little-noticed 1997 book (by their own admission), must seem like old news that should be relegated to the obituary pages. On the contrary, it concerns one of the central political issues of our time—what sustains modern democracy, and what are its future prospects. Somit and Peterson in their modest book offered both a diagnosis and a prescription. I concluded in my essay that the result was disappointing—more for what was omitted than for any commissions. My critique involved a rather subtle argument, and, judging by the authors' response (Somit and Peterson, 2001), it seems to have been lost on them as well.

We model mates' interdependent parental investment decisions as a game of Chicken. An individual is better off (in terms of reproductive success) deserting one's offspring to start a new union if one's mate stays to raise the offspring, but better off not deserting if one's mate would in turn desert the offspring. Modelling the parental investment decisions as a game of Chicken leads to four hypotheses: An individual is more likely to desert if (1) the mate is more committed to the offspring, (2) the mate has more resources to invest in children, (3) the former mate is currently unmarried, and (4) the children are older (in sharp contrast to the prediction by both Trivers [1972] and Dawkins and Carlisle [1976]). Data from the 1992 U.S. Current Population Survey provide at least partial support for all hypotheses except Hypothesis 2. In particular, the data analysis strongly supports our prediction that individuals are more likely to desert older children than younger children even when time since separation is controlled for, and rejects the earlier prediction by Trivers (1972) and Dawkins and Carlisle (1976).

Human nutrition provides a subject area in which biology and politics interact in two respects. First, nutrition is a factor in human political behavior that may affect both individual decision-making performance and mass participation. Specific conditions, such as hypoglycemia, may affect individual performance, while inadequate energy intakes and qualitative deficiencies may influence mass behavior. Second, public policy affects the nutritional status of individuals and populations. Agricultural policy, food trade policy, nutritional intervention programs, foreign and domestic food aid, and social welfare policies are among the categories of governmental outputs that help determine nutritional conditions in populations and their component groups. Nutritional status, in turn, has feedback effects through mass behavior on political inputs. Thus, human nutrition presents a problem of biopolitical interactions that involves a mutually interdependent relationship with cybernetic properties.

Partisan identification is a fundamental force in individual and mass political behavior around the world. Informed by scholarship on human sociality, coalitional psychology, and group behavior, this research argues that partisan identification, like many other group-based behaviors, is influenced by forces of evolution. If correct, then party identifiers should exhibit adaptive behaviors when making group-related political decisions. The authors test this assertion with citizen assessments of the relative physical formidability of competing leaders, an important adaptive factor in leader evaluations. Using original and novel data collected during the contextually different 2008 and 2012 U.S. presidential elections, as well as two distinct measures obtained during both elections, this article presents evidence that partisans overestimate the physical stature of the presidential candidate of their own party compared with the stature of the candidate of the opposition party. These findings suggest that the power of party identification on political behavior may be attributable to the fact that modern political parties address problems similar to the problems groups faced in human ancestral times.