James R. Flynn writes,

there is one way an individual can walk a personal path to enhanced cognitive skills. He or she must internalize the goal of seeking challenging cognitive environments — seeking intellectual challenges all the way from choosing the right leisure activities to wanting to marry someone who is intellectually stimulating. Better off still are those who develop a certain kind of character formation — a character such that I carry about within myself a stimulating mental environment I myself create. Then I would be relatively free of needing good luck to enjoy a cognitively enriched environment throughout life. I would have instant access to a portable gymnasium that exercises the mind. Books and ideas and conversation are easier to transport than a basketball court. No one can keep me from using mental arithmetic so habitually that my arithmetical skills survive.

Randall (FuturePundit) Parker sent the link. His email extracts several passages which might suggest that Flynn denies the reality of the gain in IQ over generations that bears his name. However, my reading of the whole paper is that he does think that there is a meaningful gain in problem-solving ability, and that this gain has economic significance. For example, Flynn writes,

neither our parents or our grandparents would seem dull in everyday conversation. They would be able to discuss novels as equals and would display an equally wide range of reading. They could discuss current affairs with just as broad a vocabulary and fund of general information, although they might be swayed by a lower level of political rhetoric. They would be much worse in doing on-the-spot problem solving. That would not extend to mechanical problems such as fixing a car or repairing things around the house. But they would be less adept at dealing with novel problems posed verbally or visually or abstractly. Sometimes, this ‘handicap’ would affect social conversation, particularly because they would not think such problems were very important. They would be more rule-governed and probably count that as a virtue. [emphasis added]