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.

The golden child may be the oldest one, unless it's the youngest. It may be the toughest one, unless it's the most sensitive. It's not even necessary that Mom and Dad have the same favorite - and typically they don't.

Vaccines save lives; fear endangers them. It's a simple message parents need to keep hearing.

More and more NFL players have been willing their bodies to science so that their brains can be studied even if they die of other causes.

There's no one place a virus goes to die - but that doesn't make its demise any less a public health victory. Throughout human history, viral diseases have had their way with us, and for just as long, we have hunted them down and done our best to wipe them out.

Jellyfish serve as a model for bioengineers for the same reason yeast were once so valuable to geneticists: they're simple to deconstruct.

Narcissism falls along the axis of what psychologists call personality disorders, one of a group that includes antisocial, dependent, histrionic, avoidant and borderline personalities. But by most measures, narcissism is one of the worst, if only because the narcissists themselves are so clueless.