In 1861 Paul Broca discovered that, in most individuals, the left hemisphere of the brain is dominant for language. Taking language as an example, the first part of this book explains the normal development of bodily asymmetry and lateralization, its association with hand preference, genetic aspects, geographical differences and the influence of gender. The coverage then moves on to review the association between language lateralization and psychosis, describing findings in patients with schizophrenia to suggest the dominant hemisphere may fail to completely inhibit the language areas in the non-dominant half. The language allowed to 'release' from the right hemisphere can lead to psychotic symptoms including auditory verbal hallucinations and formal thought disorder. This book should be read by psychiatrists, neurologists and neuroscientists working in the field of psychosis and other brain scientists interested in laterality.