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.

Identical twins are ideal lab specimens for studying the difference between learned and inherited traits since they come from the womb preloaded with matching genetic operating systems. Any meaningful differences in their behaviors or personalities are thus likely to have been acquired, not innate.

Well, I think of the folks who are the climate deniers as the flat Earthers and the people who say the moon landings never happened.

Indeed, the best way to think of willpower is not as some shapeless behavioral trait but as a sort of psychic muscle, one that can atrophy or grow stronger depending on how it's used.

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.

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.

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.