The application of sexual selection theory to human behavior has been the greatest success story in evolutionary psychology, and one of the most fruitful and fascinating developments in the human sciences over the last two decades. Ironically, this development would have seemed absurd only...

Machiavellian intelligence evolves because it lets primates predict and manipulate each others' behavior. But game theory suggests that evolution will not stop there: predictive capacities tend to select for unpredictability in counter-strategies, just as many competitive games favor "mixed"...