The truth, of course, is that the only necessary and sufficient condition for human beings to murder one another is the simple fact of being human.

Tamerlan Tsarnaev is telling no tales. The older of the two brothers who committed the Boston Marathon bombings was likely the one who planned the attack, but when he died in a shootout with police just days after the blasts, his thoughts and motivations vanished with him.

Sisters have ways of socializing brothers into the mysteries of girls. Brothers have ways of socializing sisters into the puzzle that is boys.

There are popular celebrities, there are unpopular celebrities and then there are the walking dead. You know the walking dead when you see them: they look like Mel Gibson, still striving for drunken charm in an L.A. County mug shot, after getting picked up on a DWI charge that included anti-semitic slurs directed at the police.

The mind and the body are inextricably entwined, and rarely are their inseparability clearer than when we're under some kind of mental pressure. The moment we start trying to learn a new skill, make a decision or otherwise think on our feet, our nervous system reacts - with accelerated pulse rate, increased respiration, even sweating.

The mind of the polyglot is a very particular thing, and scientists are only beginning to look closely at how acquiring a second language influences learning, behavior and the very structure of the brain itself.

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.