"The Designer Babies Are Growing Up" (by Katherine Lowry, Nov. 1), of course, brings up the old argument concerning the relative effect of heredity versus environment. An answer to this can be found in the studies conducted at the University of Minnesota on identical twins who were reared separately.
The study has shown that after 30 years or more, these twins show remarkable similarity in many areas, particularly in intelligence. Thus, one must conclude that heredity is the controlling factor in the human species--with environment a much lesser factor.
Frances K. Leahy