Explaining altruistic cooperation is one of the greatest challenges faced by sociologists, economists, and evolutionary biologists. The problem is determining why an individual would carry out a costly behavior that benefits another. Possible solutions to this problem include kinship, repeated interactions, and policing. Another solution that has recently received much attention is the threat o...

Nearly two million more young Americans under the age of 30 voted in the 2008 presidential elections as compared to the 2004 elections, according to new Census data analyzed and released by CIRCLE. The increase is a continuation of the trend observed in the 2004 and 2006 elections. Youth turnout was 11 percentage points higher than in 1996, which was the low point after decades of decline. Whil...