GENETICS OF EDUCATIONAL-ATTAINMENT IN AUSTRALIAN TWINS - SEX-DIFFERENCES AND SECULAR CHANGES

The relative effects of genetic and environmental factors in producing individual differences in educational achievement are compared across women and men and over birth cohorts. In a large sample of Australian twin pairs, the heritability of self-reported educational attainment did not vary among women and men born before and after 1950. In a ''ps ychometric'' model of twin resemblance, based on separate self-reports in 1981 and 1989, genetic factors explained 57% of the stable varianc e in educational achievement, while environmental factors shared by tw ins accounted for 24% of the variance. Corrections for phenotypic asso rtative mating for educational level, however, suggested that estimate d common-environmental effects could be entirely explained by the corr elation between additive genetic values for mates. Taking this into ac count, heritability of ''true'' educational attainment in Australia ma y be as high as 82% with the remaining variation being due to individu al environments or experiences. Unlike previous studies in Scandinavia n countries, results in Australia suggest that factors influencing edu cational success are comparable between women and men and for individu als born at different points during this century.