A highly entertaining, thought provoking, and pleasant read. It's sort of a blend of science and popular philosophy, the musings of a creative and bright guy. Mr. Johnson addresses a subject that is of great interest to me, namely neurotransmitter systems such as serotonin, norepinephrine, and dopamine. He also touches upon Peter Kramer's "Listening to Prozac" and the neurotransmitter personality model of C. Robert Cloninger. Mr. Johnson points out that low serotonin may be the cause of the psychological condition of rejection sensitivity, although this may actually be caused by a high level of norepinephrine as well. My only significant criticism is that Mr. Johnson may be speculating a bit much, and making somewhat of sweeping generalizations to suit his own ideas. Nonetheless, this book is well worth reading. Author of Adjust Your Brain: A Practical Theory for Maximizing Mental Health.