In response to the controversy surrounding The Bell Curve , the American Psychological Association 's Board of Scientific Affairs established a task force in 1995 to write a consensus statement on the state of intelligence research which could be used by all sides as a basis for discussion . In response to the controversy surrounding The Bell Curve , the American Psychological Association 's Board of Scientific Affairs established a task force in 1995 to write a report on the state of intelligence research which could be used by all sides as a basis for discussion , `` Intelligence : Knowns and Unknowns '' .