If I could I'd give this a 3.5.
This is my second David Wolman book, this time about the origins of handedness in the human brain, and the cultural constructions around/related to left handedness. (FYI, Wolman is a self-proclaimed proud Southpaw.)
The central pieces of the book -- both in their longer lengths and in actuality being at the middle of the book -- focus on the investigation into the neurological and biological background of body asymmetry, which leads to handedness preferences, which leads to left-handed people. Wolman speaks with many scientists, and his encounters with multiple scientific theories are well explained, and just utterly fascinating. As someone very interested in neurology and the mysterious workings of the human body, I really enjoyed this element of the book.
The other parts of the book are more focused on Wolman’s travels and encounters, with more humour. These include attending left handed golf tournaments, learning handwriting analysis and palmistry (his account of his stay as a palmistry student is particular indicative of Wolman’s humorous writing style), and visiting the Scottish castle of the supposedly dominantly left-handed Kerr clan. These accounts are at times very interesting at times, and at times not so great.
So I’d say the scientific aspects are the meat of the book, a rigorous look at what we know about left-handedness, and the cultural elements are a complementary but still important side of it. All in all an interesting and quick read, good for the curious-minded.