Measuring twinship

psychologists on twins

pp. 50-62

in: Elizabeth A. Stewart, Exploring twins, Basingstoke, Palgrave Macmillan, 2003

Abstract

Psychologists have long been interested in understanding behaviourial similarities among and differences between individuals, and twins have provided them with a rich vein of subjects for such study. A range of this psychological research seeks to specify twin-ship in terms of individual characteristics. Many studies have concentrated on such areas as temperament, personality, behaviour and cognitive abilities. Keeping in mind the reservations discussed in the last chapter about zygosity determination, heredity and environment factors, let us now examine a representative sample of these studies.