Neurochemistry
Studies in neuroscience have involved chemicals that are present in the brain and might be involved when people experience love. These chemicals include: nerve growth factor, testosterone, estrogen, dopamine, norepinephrine, serotonin, oxytocin, and vasopressin. Adequate brain levels of testosterone seem important for both human male and female sexual behavior. Dopamine, norepinephrine, and serotonin are more commonly found during the attraction phase of a relationship. Oxytocin and vasopressin seemed to be more closely linked to long term bonding and relationships characterized by strong attachments.
The conventional view in biology is that there are two major drives in love — sexual attraction and attachment. Attachment between adults is presumed to work on the same principles that lead an infant to become attached to his or her mother or father– or both.
The chemicals triggered that are responsible for passionate love and long-term attachment love seem to be more particular to the activities in which both persons participate rather than to the nature of the specific people involved.
Read more about this topic: Biological Basis Of Love