Not even identical twins can have the exact same experiences, and their brains are not wired the same way.

Most brain scientists have not taught 4th grade, and don't know very much about the classroom, even though they might study learning in some detail. Most education professionals, who often know a tremendous amount about the classroom, don't know much about the brain. That is one of the reasons why I am so skeptical about applying brain findings to the classroom.

The distance between a gene and a behavior is of greatest interest to me. The relative contributions of nature and nurture, of nucleotide and nuclear family, are perpetually fascinating to me.

Here's why this matters: Studies show that a person who is interrupted takes 50 percent longer to accomplish a task. Not only that, he or she makes up to 50 percent more errors.

Women tend to recall the details of an emotionally competent stimulus, using more of their left hemisphere to do the processing. Men tend to recall the gist aspects of an emotionally competent stimulus, using more of their right hemisphere to do the processing.

Though we have been stuffing them into classrooms and cubicles for decades, our brains actually were built to survive in jungles and grasslands. A lifetime of exercise can result in a sometimes astonishing elevation in cognitive performance, compared with those who are sedentary.

Empathy works so well because it does not require a solution. It requires only understanding.