Three sources of observation relevant to the measurement of individual differences in emotional and esthetic expressiveness were employed to study their heritability by application to a sample of some 60 pairs of young adult like-sexed twins, approximately evenly divided between male and female and MZ and DZ pairs. The sources of observation were objective test performances, trait ascription using a standard list of adjectives, and videotaped enactments of mood and esthetic performances. Perceptual and esthetic abilities do appear to have substantial heritability, although esthetic preferences do not. Heritability is also indicated for such adjectives as artistic, inventive, original, and independent. Ratings of the videotape performances yielded somewhat ambiguous results, due to the presence of a marked halo effect; the most likely interpretation congruent with earlier results is that greater MZ twin resemblances in social extroversion generated greater resemblances in the videotape situation on such other trait-rating variables as creativity, naturalness, and dominance.
