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

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.

There's plenty to read about keeping your sanity while raising children, but it's all common-sense stuff about task division and taking breaks and the relentlessly repeated magic of date night with your spouse. What's missing is some 'tude.

Every batch of sperm represents an opportunity for genetic typos - called de novo mutations - to be passed on. A 20-year-old man and woman will each pass on about 20 de novo mutations to a baby they conceive. By the time the couple is 40, a woman's total has remained at 20, while a man's has jumped to 65 - and it keeps climbing from there.

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

Your parents leave you too soon and your kids and spouse come along late, but your siblings know you when you are in your most inchoate form.

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