Psych Central  UCLA study points to evolutionary roots of
altruism, moral outrage   If you've ever been tempted to drop a
friend who tended to freeload, then you have experienced a key
to one of the biggest mysteries facing social scientists,
suggests a study by UCLA anthropologists.  "If the help and
support of a community significantly affects the well-being of
its members, then the threat of withdrawing that support can
keep people in line and maintain social order," said Karthik
Panchanathan, a UCLA graduate student whose study appears in
Nature. "Our study offers an explanation of why people tend to
contribute to the public good, like keeping the streets clean.
Those who play by the rules and contribute to the public good
will be included and outcompete freeloaders."  This finding --
at least in part -- may help explain the evolutionary roots of
altruism and human anger in the face of uncooperative behavior,
both of which have long puzzled economists and evolutionary
biologists, he said.  "If you put two