Evolutionists take the long view on sex and violence

Materialist, cultural and biological theories on why Yanomami make war

For decades, there have been three primary anthropological perspectives on why people make war: materialist, cultural, and biological. Each has a long history of application to the Yanomami. This paper considers these three alternatives. First, it summarizes the author's materialist models and what they are purported to explain. Second, it discusses more cultural explanations offered by several field researchers, concluding that some might be synthesized with a materialist perspective, while others seem irreconcilable. Finally, a range of hypotheses invoking evolved predispositions are considered and found to be directly contradicted by Yanomami ethnography, even if limited to the works of Napoleon Chagnon.

Frequency-dependent maintenance of left handedness in humans

The percentage (10-13%) of left handedness in human has apparently not changed since the Neolithic. Left handedness is heritable and appears to be repeatedly associated with some reduced fitness components; the persistence of left handedness implies that left handers have a fitness advantage in some situations. We propose that left handers have a frequency-dependent advantage in fights and for that reason a fitness advantage. To test this hypothesis, left handedness frequencies in the general population and in sporting individuals (both students and the sporting elite) have been compared, as sporting performance is likely to be a good indicator of fighting abilities. The higher proportion of left-handed individuals in interactive sports (reflecting some fighting elements), reaching 50% in some sports categories, but not in noninteractive sports, is consistent with the fighting hypothesis. The greater frequency of left handedness in males than in females is also consistent with this hypothesis, as male-male fights are universally more frequent than other combinations. The frequency-dependent advantage in fights of left handers might explain the stability of left handedness.