even wick ki pakipedia. >> he says it suppressed natural human urges. that when suppressed, they're even more destructive. what do you say to that? >> that's kind of a hydraulic model of human psychology. if you try to repress some of our impulses, they'll leak out somewhere else. it's not a correct model of psychology. a lot of human impulses are highly destructive. and part of wisdom and insight is that we ought to exert control over the darker side of human nature. >> of all the fascinating data that you discovered, what did you find the most interesting, the most surprising in your investigation? >> that certain liberal values like tolerance of gay people, tolerance of women's rights, public participation in the political process have been increasing in every region of the world for 50 years. now some regions of course are more liberal than others. western europe is much more liberal and the middle east and north africa. but even there, the opinions have been rising in the lib cer direction. that was a surprise. i'll just throw out one other fact. i