When do we fell lonely?

If you feel lonely, you are not alone. Loneliness is an unpleasant feeling that people get when they desire but are denied social contact with other people. People can be surrounded by other people, yet still feel socially isolated and lonely. The experience of loneliness is universal and occurs in all cultures. It may have origins in our evolutionary heritage, but ultimately is the result of a combination of factors ranging from genetics to personal decisions.

In the seemingly perverse logic of evolution, even extraordinarily unpleasant human emotions are adaptive. They guide us to act in ways that are in our ultimate interest. Fear makes us flee from danger. Anger compels us to attack our perceived foes, and anxiety mobilizes us to prepare for exertion. Loneliness, triggered by a desire to connect with others, reaches deep into our soul and pushes us toward others. It is a noxious stick that nature uses to remind us that we are social beings, who need and crave contact with others of our species.

Loneliness isn't all nature; nurture plays a role as well. These genes also have an environmental component that influences their development. People who “experience a low level of social support clearly feel more lonely than do carriers of that same allele who experience a high level of social support.”

As a result, some of us have a higher tolerance for being lonely, which influences the way our bodies react to social inaction. But the ability to feel loneliness is in most of us, and it's meant to drive us to seek human interaction in order to survive.