Humans share an innate drive to connect with others. We’re evolutionarily wired to crave inclusion. Eons ago, this was linked with our survival; in prehistoric times, rejection triggered fear. If someone became isolated or was ousted from the group, his or her life would be at risk.
Because the consequences of being rejected were so extreme, our brains and behavior adapted to avoid disapproval from others. In fact, research has shown that social rejection activates many of the same brain regions involved in physical pain, which helps explains why disapproval stings.