Just a quick thought today before I get back to procrastinating on my studying; Kin selection. It's widely understood that people feel more disposed to protect members of their self-determined "tribe" or those they feel genetically resemble themselves. As one evolutionist put it, "I would lay down my life for two brothers". This is subscribed typically to the idea that people do this to preserve their genetics in the mating pool (two people to pass on genes being better than one), but I feel it would be an interesting point to assess whether people would respond the same (with regards to "laying down their lives for brothers") if they knew the brothers were sterile. If this alters the response, obviously the hypothesis about genetics is true, but if it is not, it could raise pressing evolutionary questions.
Anyway, I submit for your cognitive joy; More regular and larger posts should start appearing after this Friday, when the bulk of my exams culminate.