Donal Cox writes about "The Biological Basics and the Economics of the Family" in the Spring 2007 issue of the Journal of Economic Perspectives (gated; here is the abstract) -- as part of the JEP's fine symposium on household economics.
"The biological basis for why one relative might make sacrifices on behalf of another has its origins in a puzzle that took over 100 years to solve. Charles Darwin argued that the living world is a select set of progeny whose ancestors managed to survive and reproduce. However some phenomena, such as the honeybee's suicidal defense and its hive seemed to contradict the Darwinian dictum. Hamilton's rule ... is a straightforward but far-reaching argument about the biological foundations of familial altruism. Hamilton focused on the gene rather than the individual. The honeybee's heroism could be optimal from the 'gene's-eye view': though the altruist's genetic code is lost, even more of the same code can prevail within rescued relatives." (p. 93)
P.J. O'Rourke, when asked, how and when he became a conservative supposedly answered that it was the day he became a parent.