Older fatherhood isn't all bad: testosterone rates drop about 1% per year as men age, making them less reactive and more patient, and a professionally established middle-aged man is likely to have more time and money to devote to his kids than a twenty-something who's just getting started.

It's not mere extremism that makes folks at the fringes so troubling; it's extremism wedded to false beliefs. Humans have long been dupes, easily gulled by rumors and flat-out lies.

Older siblings get more total-immersion mentoring with their parents before younger siblings come along. As a result, they get an IQ and linguistic advantage because they are the exclusive focus of their parents' attention.

Older fatherhood isn't all bad: testosterone rates drop about 1% per year as men age, making them less reactive and more patient, and a professionally established middle-aged man is likely to have more time and money to devote to his kids than a twenty-something who's just getting started.

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.

Operating-room errors hold a special terror for patients, if only because they seem like the most avoidable kind of complications. The occasional horror stories of patients who have the wrong leg removed or the wrong knee replaced generate the most headlines, as do tales of patients whose identities are mixed up entirely.