There are a lot of obstacles in the way of our understanding animal intelligence - not the least being that we can't even agree whether nonhuman species are conscious. We accept that chimps and dolphins experience awareness; we like to think dogs and cats do. But what about mice and newts? What about a fly? Is anything going on there at all?

What makes spinal-cord injuries as devastating as they are is that everything about them plays out in absolutes: they are instantaneous, utterly disabling and horribly permanent.

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.

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.

Becoming food savvy is one thing, but it's amazing how fast savvy turns to snooty, and snooty leaves you preparing three-hour meals that break your budget and that the kids won't even eat.

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.

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.