It's one of the worst-kept secrets of family life that all parents have a preferred son or daughter, and the rules for acknowledging it are the same everywhere: The favored kids recognize their status and keep quiet about it - the better to preserve the good thing they've got going and to keep their siblings off their back.

Scarily, football helmets, which do a fine job of protecting against scalp laceration and skull fracture, do little to prevent concussions and may even exacerbate them, since even as the brain is rattling around inside the skull, the head is rattling around inside the helmet.

Humans are crude linguists from the moment of birth - and perhaps even in the womb - to the extent at least that we can hear spoken sounds and begin to recognize different combinations of language sounds.

What people fear most about tragedy is its randomness - a taxi cab jumps the curb and hits a pedestrian, a gun misfires and kills a bystander. Better to have some rational cause and effect between incident and injury. And if cause and effect aren't possible, better that there at least be some reward for all the suffering.

Part-black generally means all-black in Americans' minds. Just as part-Asian or part-Hispanic or part-anything-else usually puts individuals in those minority-groups' camps.

Is there anything sadder than the foods of the 1950s? Canned, frozen, packaged concoctions, served up by the plateful, three meals per day, in an era in which the supermarket was king, the farmer's market was, well, for farmers, and the word 'locavore' sounded vaguely like a mythical beast.

The families of many athletes - incensed at the sports leagues and hoping to make games safer overall - are increasingly making the brains of players who die prematurely and suspiciously available for study. Some athletes are even making the bequest themselves.