Oxford Dictionary defines love as a strong sense of affection or physical attraction for someone (or something; i.e., a pet, cooking, etc). According to anthropologist Dr. Helen Fisher, Rutgers University (author of Why We Love), love is the action of three basic brain functions that are triggered by hormones. The predominant hormone in this function is dopamine. According to Fisher, dopamine "produces feelings of euphoria, energy, sleeplessness, and focused attention on your beloved." She also says that being preoccupied or excessively busy can dampen the effects of hormones so that an ideal potential loved one goes unnoticed. On the other hand, having free time, enough money to be comfortable, or interest in a family can enhance the effect of love hormones as can, interestingly enough, moving to a new city and struggling through a difficult situation.
From an evolutionist perspective, people love because they need to fulfill the species' need to reproduce. Fisher further says the three brain functions work together to activate an individual to seek out a mate; to focus energy on one individual from among the collective group; to develop feelings of attachment and security. Love acts like an addiction because dopamine is also the hormone involved in developing chemical addictions. Science has confirmed romantic love through artifacts of love poetry as far back in time as 4,000 years ago in the Sumerian culture, as well as confirming "evidence of romantic love in over 150 societies." Finally, while lust, which can be confused with love, dissipates after consummation, love endures and, in fact, grows stronger following consummation.