| Abstract: | Used a full adoption design to investigate the separate effects of heredity and environment on differences in the rate of communicative development of 50 adopted 1-yr-olds. Measures of infant communicative performance were obtained, along with behavioral measures, from the infants' birth mothers and adoptive parents. The adoptive home environment also was assessed. Results indicate that 19% of the correlational relationships between cognitive abilities of the birth mother and communicative performance of the infant were significant, suggesting some genetic influence on rate of communicative development in the 1st yr. In contrast, an average of 5% of the correlational relationships between the infant and cognitive abilities of both adoptive parents were significant. However, 2 measures of maternal behavior (as assessed from videotape records taken in the adoptive home) were significantly related to overall communicative performance of the infant. These were contingent vocal responsivity to infant vocalizations and vocal imitation. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
