The linguistic clumsiness of tourists and students might be the price we pay for the linguistic genius we displayed as babies, just as the decrepitude of age in the price we pay for the vigor of youth.

If you aren't just brought up in your tribe but interact with other people either directly or vicariously, through journalism and literature, you see what life is like from other points of view and are less likely to demonize them or dehumanize others and more likely to empathize with them.

In fact, without a specification of a creature's goals, the very idea of intelligence is meaningless. A toadstool could be given a genius award for accomplishing with pinpoint precision and unerring reliability, the feat of sitting exactly where it is sitting. Nothing would prevent us from agreeing with the cognitive scientist Zenon Pylyshyn that rocks are smarter than cats because rocks have the sense to go away when you kick them.

If you give people literacy, bad ideas can be attacked and experiments tried, and lessons will accumulate.

... people notice differences and expect every difference in form to convey some difference in meaning.

No one knows what the nongenetic causes of individuality are. Perhaps people are shaped by modifications of genes that take place after conception, or by haphazard fluctuations in the chemical soup in the womb or the wiring up of the brain or the expression of the genes themselves.

But in most cases even the possibility that the correlations reflect shared genes is taboo.