I've read most of Diamond's books. He is accessible, widely read, and coherent. All his books are written as arguments: he presents the problem, a point of view or hypothesis, analyses the evidence for alternative hypotheses, dismisses the alt hypotheses, and reevaluates the evidence to prove his point. A scientific approach to popular science writing. Many science writers just throw things at you: words, data, quotes from other scientists and pop culture -- as if you're sitting in a jury. Diamond SHOWS you his PoV.
In WISF Dimaond explores human sexuality, a curiosity among animals for several reasons. He explores the reasons, or phenomena, that set us apart from most other animals inc. other primates: incl. concealed ovulation, recreational sex, and the divergence b/w the sexes of investment in parenting. He investigates the evolutionary origins of these phenomena, and the effects they have today: the ultimate causes and the proximate causes and effects. An engrossing read.