The physical distance between you and another person. Simply being in someone's presence consistently—even without speaking—lays the groundwork for a connection.
In his book Dr. Jack Schafer
Your brain acts like a "territory scanner," constantly evaluating people as friends, foes, or neutral. To influence others, you must consciously send "Friend Signals" while avoiding "Foe Signals".
The length of time spent together during each encounter.
The number of times you have contact with the person over a specific period.