Integral to the concept of love is attachment. However, the emotion of love is actually just part of our attachment system that includes the biological components of attachment such as sexual and non-sexual touch as well as the emotions of love and the closeness of intimacy. Attachment adds strength to close or intimate relationships. However, it is possible to have an intimate relationship with someone without being attached to them; and it is possible to be attached to someone without being truly intimate with them.
Attachment is best understood in young children. It is absolutely essential that a baby bond with its mother through physical contact and have its physical and emotional needs met during the first days of its life. If it does not, Reaction Attachment Disorder (RAD) can occur. Characteristics of the unbonded child include a lack of empathy and emotional connectivity, extreme self-centeredness, distrust for others, acting out in extremely destructive and vicious ways, and a lack of regret for what they have done. RAD can be the precursor to Oppositional Defiant Disorder (ODD) and Antisocial Personality Disorder (ASPD)
If a child is separated from an attachment figure or the attachment figure no longer meets its needs, experiments with children shown that the child goes through three stages of detachment. First, they protest through crying or acting out. Second they go into despair where they withdraw, refusing to eat or interact with others; and finally, they detach and will even ignore the attachment figure when they are in need. (Clinton and Sibcy, 2002, pp 17-18)