The “banality of friendships”: according to social psychology, the birth of the closest bonds depends on factors that are much more predictable than we think, starting from physical proximity.
They seem to happen spontaneously, as if it were just a matter of chemistry. yet social psychology shows that behind many bonds there are surprisingly predictable mechanisms: physical closeness, repetition of meetings, gradual trust and shared activities.
The role of proximity
We think of choosing friends based on affinity or character. In reality, the first factor is often much more banal: proximity. Sitting next to someone at school, working in the same office, or going to the same gym increases the likelihood of a bond.
Psychology has been observing this phenomenon since the mid-twentieth century: in the early 1950s, the psychologist and sociologist Leon Festinger, together with some colleagues, studied the relationships between families in a residential complex for married students, discovering that friendships were born much more often between neighbors than between people further away.
The effect of familiarity
Meeting often changes the way we perceive a person. Psychology calls this phenomenon mere exposure effect: “mere repeated exposure” tends to make the familiar even more enjoyable. This mechanism helps to explain why many friendships are born in environments such as schools, courses, offices or gyms. In 1968, psychologist Robert Zajonc demonstrated that this effect affects many types of stimuli, including human faces (the more we look at them, the more we like them). In the case of friendships, the repetition of meetings therefore increases the probability that a simple acquaintance becomes something more.
From acquaintances to friends
However, familiarity alone does not transform an acquaintance into a friendship. For a relationship to change its nature, a further step is needed: trust. According to Social Penetration Theory, developed in the 1970s by psychologists Irwin Altman and Dalmas Taylor, relationships are built through progressive mutual opening: increasingly personal aspects of one’s life are shared little by little, encouraging trust and reciprocity.
A study by the University of Kansas showed that relationships consolidate more easily when people share recreational activities and informal conversations, even outside of obligatory contexts such as work or study. In other words, it’s not just the time spent together that matters, but how you spend it.
Do friends look like us?
However, there is also a less visible element: the way we interpret the world. A 2025 study, coordinated by the University of California, Los Angeles, observed that people who reacted similarly to the same videos were more likely to become friends in the following months.
This does not mean that the brain automatically “recognizes” the ideal friend, but that a certain affinity in the way of perceiving the world can favor the creation of a lasting bond. However, even if today psychology and neuroscience explain better and better how these relationships arise, it remains impossible to predict which encounters will truly turn into a friendship.
