Okay, here's the fun bit: Having a nearby grandmother consistently increased or decreased a child's chances of surviving vs. not having a grandmother around, in

Okay, here's the fun bit: Having a nearby grandmother consistently increased or decreased a child's chances of surviving vs. not having a grandmother around, in proportion to the expected number of shared X chromosomes. From the article: In other words, the effect of a grandmother perfectly tracked the DNA. "The higher the X-relatedness," the scientists write in Proceedings of the Royal Society B, "the more beneficial effect the grandmother has on that child's" survival. That the correlation held across four continents and four centuries suggests a biological, not cultural, explanation. Putting this in more specific personal terms, if you're male, your mother has a biological instinct to harm the future success of your sons, even if she is not only unaware of it but aghast at the entire idea. So, anyone still think that genes don't have much effect on behavior?