From that perspective, can we conclude our sociality is an accident if more than 95 percent of people report having friends? If you take an alien’s-eye view, friendship is a quirky phenomenon. Every friend begins as a stranger to us, typically someone we share no genes with, possibly representing an unknown threat. And yet this person may be someone we ultimately choose to disclose our innermost secrets and vulnerabilities to, or depend on more than anyone else in the world. Friendship has been documented in only a few species, but it is nearly universal in humans. Perhaps we can acquire more resources if we have friends. Perhaps they can be seen as a means to an end. If so, we should keep track in any friendship of how much we give and receive in order to ensure that we are getting our due (and hopefully more). Yet the closer friends become, the less they tend to keep track of who has done more or less for one another. Often, a friend’s primary value is the comfort of knowing we have friends. Despite the various ways friends can be directly useful to us, the fact that our friends are our friends is often an end in itself.