Right hand, left hand

Chris McManus takes familiar, almost childish, questions and for a popular audience answers them: why do European languages go from left to right, while Arabic ones read the other way? Why do clocks go clockwise? Why are human bodies symmetrical on the outside, but not on the inside? Why don´t identical twins always have the same dominant hand? What is the relatiship between handedness and speech disorders, such as stuttering? Why are male testicles unbalanced? "Right Hand, Left Hand" uses sources as diverse as the paintings of Rembrandt and the sculpture of Michelangelo.