Carol Hart, Ph.D., is a freelance health and science writer based in Narberth, Pa., just outside of Philadelphia. She is the author of Good Food Tastes Good: An Argument for Trusting Your Senses and Ignoring the Nutritionists (forthcoming, SpringStreet Books) and Secrets of Serotonin (St. Martin’s Press, 1996, with a revised and expanded second edition forthcoming in early 2008).