>>As a Bahá'í, I tend to distrust any claim that men (or women) are superior - but it is becoming increasingly clear that some differences do exist. (No differences that make one gender superior to the other, just different strenghts in each case.)
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>Don't take so much seriously. :)
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>But one thing make people smarter. A Dr. friend of mine said that "mixed raced nations everytime be smart than others". Because "smart gene" dominate "stupid gene" (I know that was so basically explain but my english only enough for that).

There's the other study which showed how speaking multiple languages keeps your wits sharp longer. Helps delay the progress of senile dementia. So it may also help during development - if you're in a mix, you have to speak languages, you have to use more of your brain, you do more mental pushups, and you generally develop the brain muscle. Which then makes you smart enough to beat any IQ testing :).