I am writing in response to your article "The Flynn Effect and Mental Decline" in which you state that the rise in the average I.Q.'s is caused by environment, i.e., improved nutrition, the increase in complexity of the English-speaking culture.
Another explanation can be attributed to Rupert Sheldrake, who writes of "morphic fields." Sheldrake postulates that knowledge is spread throughout each species through these fields. He found that birds in England learned how to open milk bottles. This knowledge spread mysteriously to other groups of birds far away. He also used crossword puzzles; he proved that if people take a crossword puzzle after others have taken it, they will do better than groups who took the puzzle earlier when it first came out. Sheldrake appeared on KCET last year, discussing his theories at length. I have his videotape called "Seven Experiments That Could Change the World." If you haven't already heard of him you and your readers should listen to his tape or buy his books.