A jellyfish is little more than a pulsating bell, a tassel of trailing tentacles and a single digestive opening through which it both eats and excretes - as regrettable an example of economy of design as ever was.

There's a deep-freeze of sorts for all good intentions - a place that you store your plans to make changes in your life when you know you're not going to make them at all.

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 a sort of sibling moratorium when you're establishing yourself as an adult. So much of your energy has to be focused on other things like work and kids. But when people become more settled, siblings tend to regroup because now you're building a new extended family.

As the National Football League and other pro sports increasingly reckon with the early dementia, mental health issues, suicides and even criminal behavior of former players, the risk of what's known as chronic traumatic encephalopathy (CTE), is becoming clear.

Introverts listen better, they assess risks more carefully, they can be wiser managers. It's not for nothing that the Silicon Valley billionaires are so often the retiring types.

Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.