Identical twins reared apart. Because they share an identical genotype, twins make ideal subjects for investigating the degree to which various environmental conditions affect personality. The classical method of studying this phenomenon, and the subject of a book by Susan Farber

(Identical Twins Reared Apart, New York: Basic Books, 1981), is the study of identical twins separated early in life and reared apart. Much of Farber’s discussion focuses on a LO3 comparison of IQ scores. The data for this analysis appear in the accompanying table. One member (A) of each of the n = 32 pairs of twins was reared by a natural parent;

the other member (B) was reared by a relative or some other person. Is there a significant difference between the average IQ scores of identical twins when one member of the pair is reared by the natural parents and the other member of the pair is not? Use a = .05 to draw your conclusion.

Pair ID Twin A Twin B Pair ID Twin A Twin B 112 113 109 228 100 88 114 94 100 232 100 104 126 99 86 236 93 84 132 77 80 306 99 95 136 81 95 308 109 98 148 91 106 312 95 100 170 111 117 314 75 86 172 104 107 324 104 103 174 85 85 328 73 78 180 66 84 330 88 99 184 111 125 338 92 111 186 51 66 342 108 110 202 109 108 344 88 83 216 122 121 350 90 82 218 97 98 352 79 76 220 82 94 416 97 98