Need to belong
Human beings are social in nature and they to connect with others ion a closer relationship that is enduring. It is because when they belong and have a feeling of support from close intimate relationships they will tend to be happier and healthy compared to when they are alone.
Proximity
Closeness in terms of geographical is likely to predict liking between two people in a particular relationship. Through proximity, people are capable of interacting in what is called functional distance. It entails the number of times the path of people will cross hence enabling them to discover similarities towards each other that ultimately lead to relationship.  For instance, if students starting their first classes together are assigned to seat randomly, after sometimes they are likely to be friends with those who were seated next to them.
Disclosure reciprocity
It applies when we believe that a certain person likes us. In that instance, when we have instincts that a certain person likes us, we are likely to assume a likeable status in their presence hence making them to like us more.
Social Ostracism
Ostracism is a feeling that is common, and almost everybody has experienced it. It causes real pain due to the reason that our sense of belonging and self-esteem is compromised. Individuals who are ostracized will exhibit a range of behaviors to avoid the feeling. They will tend to mimic body language of ostracized as well monitoring their facial expression carefully. They will do anything to please them or force others to pay attention to them. Ostracism is directly linked to common criminals such as shootings that have taken place over the past years. It is because people will respond differently to the act of ostracism. An individual will deal with first stages of ostracism with pain and an urge of trying to cope with the situation. If the exclusion persists, then it will lead to depression and eventually amount to helplessness. At that point, the affected individual is capable of doing anything because of the feeling that they cannot take it anymore.