O estudo revisitado das influências genéticas e ambientais na personalidade

Abstract

About a century and a half of research on the genetic and environmental influences on personality was examined. For that, the main studies and reviews of the different decades that had worked with pairs of twins as their primary sample were chosen. More of fifty of them gathered information about the changes on sampling and methodology of data collection and analyses, as well as the difficulties and improvements on the acquisition of scientific knowledge. The significant genetic contribution on personality variation was the first thing to be verified when the studies of the end of the first half of the century demonstrated successively that identical twins were more alike than fraternal twins. From that, the goal of the second half turned towards the quantitative measure of the different variables contributions; that is, to comprehend numerically how much of the differences in personality, found within a certain population, are conditioned to genetic variation (genetic differences) and how much is conditioned to environmental variation (differences on shared and nonshared environment).