In 1985 I reviewed deceit and self-deception in chapter 16 of my book and in 1991 I published a casual essay on the topic, notable mostly for suggesting a novel way of communicating with animals (Trivers 1991). The preceding paper is my best understanding of self-deception to date. It grew out of a conference organized at Hunter College in New York by Peter Marler and Dori LeCroy. As the paper suggests, there is an enormous amount of work waiting to be done on all aspects of self-deception, from its neural substrate, to an integration of the psychological findings on the subject, to the development of a deeper theory. People from a wide range of disciplines can contribute. For an interesting study of lie detection and deception, see Etcoff et al. (2000).