The sample eligible for the present study included the 350 families randomly assigned to receive the SAAF intervention and the 291 randomly assigned to the control condition who completed the posttest; families assigned to SAAF were oversampled. Because only the 4-repeat and 7-repeat alleles are well characterized in terms of biological effects, only participants (N = 340) with these alleles were included in the analyses. Three additional participants were excluded because their data for 5HTT could not be characterized unambiguously.
