It's not really rocket science. It's just simple 'common sense' which, as we see all too often, is somewhat uncommon (as is evident at most forums where we discuss societal issues and problems).
Did I put "common sense" on my list of defining traits for humans? NO. Animals (non humans) are endowed with common sense. According to most thinking, including mine, we have at least what other animals have. However, something on my list nullifies common sense. It is both a gift and a curse. Here is a hint. It isn't tools and it isn't language.