Do Battered Heads Proliferate ?

Recently there's been discussion of brain damage produced in sports, especially when people hit footballs with their heads.

Anecdotal evidece suggests that teachers of games and what is absurdly misnamed 'Physical Education' are conspicuously less intelligent than their colleagues. If that is so it may be that people who have suffered brain damage are propagating their disability by organising the brain damage of the young.

I'd like to see research into the intellectual incapacity of 'PE' teachers.