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.

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.

We're learning how important it is both to preserve sibling relationships if they work and repair them if they're broken. We're also learning a lot about nonliteral siblings - stepsiblings, half-siblings - and the surprising power they can have.

More and more NFL players have been willing their bodies to science so that their brains can be studied even if they die of other causes.

Some of the most rewarding times my brothers and I have are when all of us get together, and we can see what we've been building genetically and culturally.

My own life has in some ways been a decades-long tour of the sibling experience. I have full sibs, I have half-sibs, and for a time I had step-sibs.

It's a deep and all but certain truth about narcissistic personalities that to meet them is to love them, but to know them well is to find them unbearable. Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.