Fine sets out to examine an assumption, both explicit and explicit, in our culture that men are genetically predisposed to take risks because they produce more testosterone than women. She examines this assumption thoroughly and systematically. I enjoy books that challenge me and send me to other books and research, and Testosterone Rex certainly did both.

I have read a number of reviews that accuse this book of being a straw man argument and cherry-picking evidence. I found neither to be true. In fact, this is one of the strengths of this book.

Although the organizing principle of this book (men are more likely to take risks because testosterone) could be said to be a straw man argument, Fine is careful to present this point of view not by plucking it from the thin air, but by presenting a documented instance of this idea. Often, she presents and cites a number of instances.

The idea of cherry-picking seems shocking to me. Fine repeatedly presents data that doesn't entirely agree with her overall hypothesis. In some cases, she does find fault with the methodology of these studies, but in others, she modified her hypothesis based on the available data.

This is a superb example of what popular science writing should be. It presents the cutting edge of science and explains how this challenges the world we think we know.