When viewed from a human evolutionary perspective, being nice doesn’t make that much sense—after all, it’s hard to reason with a hungry lion. Despite that, empathy appears to have been as sharp a survival tool as a spear. Much of our increased neural volume over the last 2.5 million years has been dedicated to growing our interpersonal capacities. From understanding to attachment to cooperation—and everything in between—it can be argued that the complexities of relationships have driven human evolution due to the fact that we are distinctly social animals.