The mediation of development in maternally and paternally related half-siblings by passive, evocative, and active genotype -environment effects
This study was designed to evaluate the developmental progression proposed by Scarr and McCartney (1983) of three categories of genotype-environment correlation. Forty-seven families, consisting of 140 children and 94 adults, participated in the study. Passive genotype-environment correlation was hypothesized to decrease across three age groups; 4 to 7, 8 to 12, and 13 to 18, while evocative and active genotype-environment correlation were hypothesized to correspondingly increase. Passive genotype-environment correlation was measured by the differential correlation for IQ between natural parent/child and step-parent/child pairs; evocative genotype-environment correlation was measured by the correlation between temperament and family environment; and active genotype-environment correlation was measured by the correlation between IQ and self-perception of cognitive competence. This study also sought to assess the "maternal effect" on intellectual development by comparing the IQ correlation between (a) maternally-related half-siblings and paternally-related half-siblings; and (b) the mother and the midmaternal half-siblings versus the father and the midpaternal half-siblings.^ The results showed that passive genotype-environment correlation was significant for all age groups combined, and that evocative and active genotype-environment correlation were significant within each age group. Few of the evocative active genotype-environment correlations demonstrated the expected pattern across the age groups. Only within the 13 to 18 age group was the hypothesized ordering partially confirmed with the active and evocative correlations significantly different from the passive, but not from each other. A maternal effect on intelligence was supported by a significant difference between mother/maternal half-sibling correlations, but did not receive support from the test of the difference between maternal and paternal half-sibling correlations. These findings suggest the importance of genotype-environment correlation as an arbiter of an individual's transactions with the environment and further operationalizations of the genotype-environment correlations must be made to insure their verisimilitude beyond the instruments selected for this study. ^
Hershberger, Scott Laurence, "The mediation of development in maternally and paternally related half-siblings by passive, evocative, and active genotype -environment effects" (1990). ETD Collection for Fordham University. AAI9020011.