In the early twentieth century, Robert Hertz, a French anthropologist, and Cesare Lombroso, the Italian criminologist, debated the causes and consequences of left-handedness. According to Lombroso, left-handed individuals were more likely to be criminals. Hertz disagreed. For him, to restrict left-handedness was to suppress individual expression. In his book, On the Other Hand: Left Hand, Right Brain, Mental Disorder, and History (Johns Hopkins University Press, 2017), Howard I. Kushner explores the fascinating and circuitous history of left-handedness. By looking at a wide variety of scientific research, as well as the cultural meanings attached to left-handedness, Kushner breaks down the binary between nature and nurture that has characterized most explanations of what some researchers have called non-right-handedness. Ultimately Kushner argues that discrimination against left-handers can be read as a barometer for a given society’s toleration of diversity.