Toxins love to get you while you're young. Lead, mercury, secondhand smoke and sundry other environmental nasties do a lot more damage when tissue is immature, vulnerable and growing than when it's mature and comparatively fixed.

When we're awake, cortisol can fragment memories - one reason eyewitness crime scene accounts are so unreliable. But at night that very fragmentation allows creative recombinations of ideas.

Humans are crude linguists from the moment of birth - and perhaps even in the womb - to the extent at least that we can hear spoken sounds and begin to recognize different combinations of language sounds.

In both children and adults, there can be a hard-to-deny link between a robust sense of hope and either work productivity or academic achievement.

All behavioral or mood disorders - including depression, OCD, ADHD and addiction - have some neurochemical components, but sufferers can still work to overcome them.

Toxins love to get you while you're young. Lead, mercury, secondhand smoke and sundry other environmental nasties do a lot more damage when tissue is immature, vulnerable and growing than when it's mature and comparatively fixed.

People with anxiety disorders such as OCD know that nothing can be more paralyzing than having too many options. Go to a store to buy a sweater, find four that you like and the odds are pretty good you'll stare and stare... and buy nothing at all.