ABSTRACT
The prenatal environment of twins is undoubtedly more hazardous than that of singletons and J. A. Churchill suggested that adverse factors during this period were primarily responsible for the subsequent delayed development observed in twins. H. Lytton and D. Conway provided evidence that the linguistic environment of twins was impoverished compared with that of singletons and suggested that this rather than prenatal or perinatal factors was responsible for their language delay. The majority of the studies reviewed failed to control for either prenatal or perinatal environmental factors. This study attempts to overcome this by: investigating the differential effects of prenatal and postnatal twin environments on development, and by examining the pattern of development of twins and singletons from the age of one month to 4 years of age. In conclusion, the results of the study suggest that the prenatal twin environment does not have an adverse effect on subsequent intellectual development.
