In Reply.–Dr Kolisch's response to my review of the Firkowska et al paper1 suggests that genetic influences may underlie the powerful effect of family life on a child's IQ, as presented in the study. His comments are, I believe, quite relevant and they raise several fundamental points of interest.
First, one must ask whether or not IQ implies a genetic linkage and if so to what extent does this genetic influence carry over to a child's performance. I believe that it can be safely concluded, based on a large number of studies, that undoubtedly bright parents have bright offspring and that such correspondence in functioning across generations cannot be solely accounted for by family environment. However, the questions arise as to (1) how much is nature and how much is nurture, and (2) of the proportion that is nurture, what amount is amenable to extrafamilial remediation or influence.