Intelligence

Table 1 

Comparison of cognitive performance measures at ages 7 and 17 in biological and adopted (White, mixed-race, and Black) children, all reared in middle-class White families

Table 1 

Comparison of cognitive performance measures at ages 7 and 17 in biological and adopted (White, mixed-race, and Black) children, all reared in middle-class White families

Children’s background	Age 7 IQ	Age 17 IQ	Age 17 grade point average	Age 17 class rank (percentile)	Age 17 school aptitude (percentile)a
Biological parents	120	115	–	–	–
Nonadopted, with two White biological parents (N at 7 = 143; N at 17 = 104)	116	109	3.0	64	69
Adopted, with two White biological parents (N at 7 = 25; N at 17 = 16)	112	106	2.8	54	59
Adopted, with one White and one Black biological parent (N at 7 = 68; N at 17 = 55)	109	99	2.2	40	53
Adopted, with two Black biological parents (N at 7 = 29; N at 17 = 21)	97	89	2.1	36	42

aBased on national norms (weighted mean of four percentiles). Adapted from Weinberg et al. [ 67 [67] .

http://www.medical-hypotheses.com/article/S0306-9877(08)00245-4/fulltext


https://www.newstatesman.com/2018/04/iq-trap-how-study-genetics-could-transform-education