The best you can sometimes do is learn to take a breath, count to ten and simply accept that try as you might, no, your husband will never, ever learn not to drop a wet towel on the bed. That acceptance too counts as resolving a fight.

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

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.

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

We are all born with an innate understanding of interpersonal equity - the idea that if you lend me your rake today, I'll respond in kind when you come to borrow my shovel tomorrow. Or nearly all of us are born with that. Psychopaths aren't.

When you learn conflict-resolution skills in the playroom, you then practice them on the playground, and that in turn stays with you. If you have a combative sibling or a physically intimidating, older sibling, you learn a lot about how to deal with situations like that later in life. If you're an older sibling and you have a younger sibling who needs mentoring or is afraid of the dark, you develop nurturing and empathic skills that you wouldn't otherwise have.

Kids whose puberty begins too soon face not just psychological risks, but physical ones too, with an increased likelihood of cancer, as well as skeletal changes that could prevent them from attaining their full adult height.