Conjoined twins born before the advent of surgical separation techniques have long been of special interest to scientists. Sharing an identical genetic make-up and an identical environment, these twins have provided a unique opportunity for the study of innate and cultural determinants on the individual. Psychological Profiles of Conjoined Twins probes the striking differences in personality, ability, and interests between such twins--and consequently reexamines the prevailing assumptions in current psychological research. Smith's thoroughly documented book questions the pervasive view that human characteristics may be reduced to a simple ratio of heredity and environment. He investigataes the lives of the first recorded conjoined twins, Chang and Eng, and the lives of other, lesser known conjoined twins. The author also presents an intriguing study of the representation of conjoined twins in literature. The final chapters discuss vital philosophical and scientific questions raised by the lives of such twins, with particular emphasis on the over-simplification of traditional heredity/environment approaches.