Propinquity

Propinquity can mean physical proximity, a kinship between people, or a similarity in nature between things.
In social psychology, propinquity (from Latin propinquitas, nearness) is one of the main factors leading to interpersonal attraction. It refers to the physical or psychological proximity between people. For example, two people living on the same floor of a building have a higher propinquity than those living on different floors. See propinquity effect.
Propinquity is also one of the factors, set out by Jeremy Bentham, used to measure the amount of pleasure in a method known as felicific calculus.
The propinquity effect is the tendency for people to form friendships or romantic relationships with those whom they encounter often. In other words, relationships tend to be formed between those who have a high propinquity. The propinquity effect is usually explained by the mere exposure effect, which holds that the more exposure a stimulus gets, the more likeable it becomes.