As the brain matures, one thing that happens is the pruning of the synapses. Synaptic pruning does not occur willy-nilly; it depends largely on how any one brain pathway is used.

The human brain has evolved the capacity to impose a narrative, complete with chronology and cause-and-effect logic, on whatever it encounters, no matter how apparently random.

Lies can be verbal or nonverbal, kindhearted or self-serving, devious or bald-faced; they can be lies of omission or lies of commission; they can be lies that undermine national security or lies that make a child feel better. And each type might involve a unique neural pathway.

In the modern world, the anxious temperament does offer certain benefits: caution, introspection, the capacity to work alone. These can be adaptive qualities.

Whatever the reason for any one individual's tendency to gain weight, the only way to lose the weight is to eat less and exercise more.

The 20s are like the stem cell of human development: the pluripotent moment when any of several outcomes is possible. Decisions and actions during this time have lasting ramifications.