Destroy Your IQ?

Two serious fight-related head injuries can impact a teenage boy’s IQ to the equivalent of losing a whole year of school. For girls, a similar loss of IQ is possible after just one serious fight-related head injury. Falls in IQ are linked to lower academic and professional performance, behavioral problems, mental disorders, and decreased life spans. Each fight-related injury resulted in a drop of 1.62 IQ points for boys and a fall of 3.02 IQ points for girls. Missing a whole academic year is equivalent to a loss of between 2 and 4 IQ points.

Journal of Adolescent Health, August 2013