The follow-up to Sexual Behaviour in the Human Male, this book was de facto revolutionary at the time, though much of it is kind of obvious to the modern reader. The two books are in many ways the same, going through the data obtained with the same methods and presenting it thoroughly. The insane attention to detail means that realistically you have to skip through a lot of the discussion and scrape the findings out of the sludge.

When reading the first book, the gimmick of reading a discussion of human sexuality like one might read a discussion of gall wasp behaviour drew me more - by the time I read this book, I grew a little tired of it. It's still a good read, his methodology and findings are still one-of-a-kind, but it's pretty hard to slog through 1700 pages of data and still be engaged. 

3.5*s because despite this being an objectively cool study it's also objectively extremely boring.