Biological Differences in Intellectual Functioning

Publisher Website
Google Scholar
Abstract
To gauge the extent of the influence of genic elements in intellectual functioning during later life, data were obtained from a psychometric study of aging twins organized in 1946 as part of a long-term investigation of the hereditary aspects of aging and longevity. Greater similarity was observed between the scores of one-egg than of two-egg twins even after the age of 60, indicating the persistence during adult life of gene-specific differences in mental functioning. Average test scores were as high for the twins as those reported for single-born aged persons in the general population. During a 12-year follow-up period statistically significant decline occurred only on speeded motor tasks and this decline may represent general concomitants of aging. By contrast, the formula for critical loss, may reflect specific cerebrovascular changes associated with high five-year mortality.

This publication has 0 references indexed in Scilit: