Final answer:
Proximity is the most influential factor in determining friendships and romantic relationships.
Step-by-step explanation:
The most influential factor in determining friendships and romantic relationships is proximity. People are more likely to form relationships with those they have regular contact with. Research shows that friendships are more common among people who live near each other. This is because regular interaction provides opportunities to get to know each other better.
The single most influential factor in forming relationships is proximity. Regular contact increases the likelihood of friendship due to more opportunities to connect. Neighbors often become friends as a result of frequent interaction.