What did I know about IQ and intelligence before reading James R. Flynn's What Is Intelligence? Almost nothing. I had seen the stories about identical twins separated at birth. It's all heredity and nothing can be done. But most parents work hard to provide nurturing environments for offspring. Hope springs eternal.
Everyone knows that athletic records continue to fall. (And most of us have benefitted from some sort of chemical help almost from birth.) Likewise, the "Flynn effect" takes note of significantly rising IQ scores for some years. James Flynn points out that nature and nurture have interacted in beneficial ways. He makes a good case and offers a pleasurable read. What are some of the trends that matter?
Many do well these days because they can, moreso than ever before. "A greater pool of those suited by temperament and therefore inclination to be mathematicians or theoretical scientists or even philosophers, more contact with people who enjoy playing with ideas for its own sake, the enhancement of leisure, these things are not to be despised. And all of this has come about without an upgrading of the human brain through better genes or environmental factors that have a direct impact on brain physiology." (p. 174)