Intimacy involves the feeling of being in a close, personal association and belonging together.
It is a familiar and very close affective connection with another as a result of a bond that is formed through knowledge and experience of the other.
In human relationships, the meaning and level of intimacy varies within and between relationships.
Sustaining intimacy for a length of time involves well-developed emotional and interpersonal awareness. Intimacy involves the ability to be both separate and together participants in an intimate relationship. Murray Bowen called this "self-differentiation," which results in a connection in which there is an emotional range involving both robust conflict and intense loyalty.
Lacking the ability to differentiate oneself from the other is a form of symbiosis, a state that is different from intimacy, even if feelings of closeness are similar.