I saw this story only yesterday and had half a mind to start a thread about it, which would have generated a chorus of "do keep up"s and I wouldn't have got the joke!
jim's link didn't work because the left bracket touched the
http and fooled the parser, or some such (I'm probably making this up). I always hit return so links start on a new line.
http://www.cell.com/cms/attachment/2040068276/2053595203/gr2.jpg
Shame on me for not delving into the study's methodology. Shame on them for the selective geography. Maybe it was a low-budget affair and whatever "stickers" are, they're only impressive enough to children for them to be selfish with them in certain parts of the world. If westerners only behaved in an equivalent way in response to sweets, say, there would probably have been a lot of parental backlash and negative publicity.