I tried to get in their heads, understand their minds, the nature of their genius. I sort of felt I was seeing things that they had in common, and there were things that had to do with aloneness. They all had the ability to concentrate with a sort of intensity that is hard for mortals like me to grasp.

* Intelligent people are flexible and able to thrive in different settings.

* They understand how much they don't know.

* Intelligent people let themselves become fascinated by things others take for granted.

* They're open-minded. Smart people don't close themselves off to new ideas or opportunities.

* They like their own company.

* They have high self-control.

* Highly intelligent people tend to have a great sense of humor.

* Smart people can almost feel what someone is thinking or feeling.