http://www.cbsnews.com/stories/2007/11/21/health/main3530786.shtml
(CBS/AP) Even infants can tell the difference between naughty and nice playmates, and know which to choose, a new study finds.
Babies as young as 6 to 10 months old showed crucial social judging skills before they could talk, according to a study by researchers at Yale University's Infant Cognition Center published in Thursday's journal Nature.
"Our results suggest that infants, just like adults, are able to tell the difference between those who act positively vs. negatively toward others, and that they tend to approach those who act positively and to avoid those who act negatively," study lead author Kiley Hamlin tells CBS News partner WebMD via email.
Whoops. That third paragraph. Color me wrong; if people knew, we wouldn't have had Stalin, Attila, Hitler, Charles Manson, the Osmond family teeth, and the wife-beating husband.