I found this when I was writing an item about Daniel Patrick Moynihan, and his famous report The Negro Family:The Case For National Action,[ Office of Policy Planning and Research, United States Department of Labor, March 1965]

The report is a period piece, but one interesting thing is Moynihan's environmental theory of IQ:

"In the report, to make note of another statement that angered civil-rights leaders, Moynihan pointed out that Negro children have generally lower I.Q.'s than white children, a fact which appears to be true but which civil-rights leaders do not care to have mentioned in official Government studies for the reason that racists tend to use it as evidence that Negroes are somehow an inferior people.

Moynihan, however, taking a view diametrically opposed to that of the racists, traces lower Negro I.Q.'s, again, to broken and fatherless Negro homes. "The family is society's basic unit," Moynihan has written. "The most important things a person learns are taught by the family in a process that may begin at as early an age as four weeks. It would seem that when one parent has to do the work of two, less learning takes place. Dr. S. Oliver Roberts, a Fisk University psychologist, measuring the changes in I.Q.'s of Negro children, recently reported that 'those boys and girls in broken homes at age 10 had definitely lower I.Q.'s than the other children studied.'" Moynihan of the Moynihan Report, By Thomas Meehan, July 31, 1966

The odd thing about this theory is that Moynihan, who went from being a shoeshine boy in Hell's Kitchen to being an academic, White House advisor, Ambassador To The United Nations, and United States Senator, was himself the product of a "broken home," his Irish newspaperman father having deserted his mother, a practical nurse.

In spite of this "broken home", Moynihan

• Graduated top of his class from Benjamin Franklin High School, in Harlem.
• Passed the open exams for City College
• Spent a year at City College
• Enlisted in the Navy, which sent him to Tufts, as part of Navy's V-12 officer- training program
• Got a B.A. cum laude from Tufts in 1948
• Meehan: "And, knowing a good academic climate when he saw one, he then went on to Tufts's Fletcher School of International Law and Diplomacy from which he received an M.A. in 1949. (Some years later, in 1961, he received a Ph.D. there.)"
• Between M. A. and Ph. D, he was a Fulbright Scholar at the London School of Economics

That's pretty good for a shoeshine boy from broken home.

How could this happen? Well, presumably, he was a very bright shoeshine boy from a broken home, with parents who were fairly high on the IQ scale, even if they didn't have much education.