Psychophysiological correlation of 17-ketosteroids and 17-hydroxycorticosteroids in 21 pairs of monozygotic twins

Abstract

Twenty-one pairs of healthy monozygotic male twins of college age have been observed in an attempt to correlate individual personality structure with characteristic and relatively enduring patterns of pituitary adrenocortical function. Ten pairs of comparable dizygotic male twins have been studied by the same methods. High levels of 17-OHCS excretion were found in individuals with forceful yearnings for close personal involvement or with active defenses against the threat of intimacy. Individuals with low 17-OHCS levels were more effectively isolated by well-organized neurotic defenses. High 17-KS levels were found in energetic, ambitious individuals with strong aggressive drives and equally strong defenses against them. Those with low 17-KS were over-controlled with apparently limited innate drive endowment. A one way analysis of variance was computed for both monozygotic and dizygotic. twins. The F ratio indicated that height, 17-KS mean values, and day-to-day variation in 17-KS might be influenced by genetic factors. The intra-class correlation in 17-OHCS means was just as great in dizygotic as in monozygotic pairs but the correlation in 17-KS means in monozygotic pairs was much higher than in dizygotic pairs. A contingency table was constructed by grouping the variation in 17-OHCS and 17-KS into quartiles. In 14 out of the 21 pairs of monozygotic twins both members of the pair were in the same quartile for 17-OHCS and 17-KS and both members of all the other pairs were in adjoining quartiles. The pyschological characteristics shared by all of the subjects in each contrasting quartile suggest meaningful correlations of steroid patterns with different but interrelated quantifiable ranges of psychological response corresponding respectively to the mean levels of the 17-OHCS and of the 17-KS.