It's only natural to become at least a liiiiittle protective of your things. The lizard portion of the human brain guards resources as if our lives depend on it, which in some cases can be true. However, in modern society, we're not in the wilderness fighting over the last scrap of deer meat around the communal fire we've got bigger prizes on our minds, and when it comes to siblings and their shared inheritance, you can count on that lizard brain getting fired up over something far more complex than the next meal.