IN A STUDY published in 2002, anthropologist Helen Fisher of Rutgers University and a multi-disciplinary team of experts recruited 40 young people madly in love - half with love returned, the other half with love rejected - and put them into an MRI with a photo of their sweetheart and one of an acquaintance. Each subject looked at the sweetheart photo for 30 seconds, then - after a diversion task - at the acquaintance photo for another 30 seconds. They switched back and forth for 12 minutes.
The result was a revealing photo album of the brain in love. Think like a brain scientist and you too would be excited by activity in the right ventral tegmental area. This is the part of the brain where dopamine cells project into other areas of the brain, including the posterior dorsal caudate and its tail, both which are central to the brain’s system for reward and motivation. The sweetheart photos, but not the acquaintance photos, were the cause. In addition, several parts of the prefrontal cortex that are highly wired in the dopamine pathways were mobilized, while the amygdala, associated with fear, was temporarily mothballed
When Love Blossoms
Dr Fisher explained in a lecture at the 2004 American Psychiatric Association’s annual meeting, is not an emotion. Rather, it’s "a motivation system, it’s a drive, it’s part of the reward system of the brain." It’s a need that compels the lover to seek a specific mating partner. Then the brain links this drive to all kinds of specific emotions depending on how the relationship is going. All the while, she went on to say, the prefrontal cortex is assembling data, putting information into patterns, making strategies, and monitoring the progress toward "life’s greatest prize."
Love also hurts. Dr Fisher cited one recent study where 40 percent of people who had been dumped by their partner in the previous eight weeks experienced clinical depression and 12 percent severe depression. It is estimated that 50 to 70 percent of female homicides are committed by lovers and spouses. Annually one million women and 400,000 men are stalked.
Dr Fisher divides love into three categories involving different brain systems: 1) Lust (the craving for sexual gratification), driven by androgens and estrogens; 2) Attraction (or romantic or passionate love, characterized by euphoria when things are going well, terrible mood swings when they’re not, focused attention, obsessive thinking, and intense craving for the individual), driven by high dopamine and norepinephrine levels and low serotonin; and 3) Attachment (the sense of calm, peace, and stability one feels with a long-term partner) driven by the hormones oxytocin and vasopressin.
"I think the sex drive evolved to get you out there to get looking for anything at all," she told her audience. Romantic love, she thinks, developed to focus one’s mating energy on just one individual while attachment works to tolerate this individual long enough to raise children as a team.
These systems are also connected. "Don’t copulate with people you don’t want to fall in love with," she half-jokingly tells her students, "because indeed you may do just that." Testosterone can kickstart the two love neurotransmitters while an orgasm can elevate the attachment hormones. But the brain systems remained separate units, probably to allow each partner to cheat on the other. This would have enhanced Alley Oop’s chances of transmitting his genes. A philandering Clan of the Cave Bear babe, meanwhile, would have had an insurance policy had her main squeeze ended up as a baby mastodon’s throw toy.
Romantic love, Dr Fisher believes, is a stronger craving than sex. People who don’t get sex don’t kill themselves, she said. On the other hand, it is not adaptive to be romantically in love for 20 years. "First of all," she confided, "we would all die of sexual exhaustion." Not surprisingly, the subjects in her study who had been in love the longest (17 months) displayed markers in the brain indicating the beginnings of "the satiation response."
In a related undertaking, Dr Fisher found evidence that romantic love exists in 150 societies, even though it is discouraged in many of them. But with many women from these countries now entering the workforce and acquiring a sense of independence - together with medical science keeping us relatively younger longer - we can expect to see romantic love on the rise worldwide, she predicted.
SIGN UP FOR MY FREE EMAIL NEWSLETTER
When Love Fades
High levels of oxytocin and vasopressin may interfere with dopamine and norepinephrine pathways, Dr Fisher explained in the same talk, which may explain why attachment grows as mad passionate love fades. The antidote may be doing novel things together to goose the two love neurotransmitters.
Meanwhile, elevated testosterone can suppress oxytocin and vasopressin. There is good evidence, Dr Fisher said, that men with higher testosterone levels tend to marry less often, be more abusive in their marriage, and divorce more regularly. The reverse can also be true. If a man holds a baby, levels of testosterone go down, perhaps in part because of oxytocin and vasopressin going up.
In a 54-item questionnaire Dr Fisher prepared for 430 Americans and 420 Japanese, 95 percent responded yes to the question, "Have you ever been dumped by someone you really love?" An equal number also dumped someone who really loved them. Getting dumped makes you love the person harder, Dr Fisher noted, a term she calls "frustration attraction."
Psychologists also refer to "abandonment rage" and "frustration depression," which may paradoxically work to hasten the relationship’s end. Then comes resignation and despair, where the brain’s reward system begins to realize the you are never going to get what you want. Despair may seem counterproductive, but it is in essence "a failure of denial" that allows us to see the world for what it is and sets us on the road to finding a more suitable partner.
Although the brain images of the men and women in Dr Fisher’s study were basically the same, she and her colleagues did find activity in men in a region of the parietal of the temporal lobe associated with the integration of visual stimuli. Ninety percent of pornography is for men while women spend their lives trying to look good for them, Dr Fisher explained. The Darwinian explanation is that the studs of Leakey Land picked their partners by sizing them up visually.
In women, there was more activity in regions associated with memory recall. From an evolutionary perspective, looks probably weren’t enough to determine if a prospective mate would be a good provider and protector. The belle of the Great Rift Valley needed to remember what that suave suitor with the sexy brow ridge grunted yesterday and promised two months ago.
Love at Risk
At a different APA forum, "Sex, Sexuality, and Serotonin," Dr Fisher warned that antidepressants may jeopardize romantic love. As well as high dopamine and norepinephrine, she said, romantic love is characterized by low serotonin. Low serotonin would explain the obsessive thinking attached to romantic love. In her MRI study, her subjects reported that they thought about their loved one 95 percent of the day and couldn’t stop thinking about them. This kind of obsessive thinking is comparable to OCD, she said, also characterized by low serotonin.
Serotonin-enhancing antidepressants, she said, blunt the emotions, including the elation of romance, and suppress obsessive thinking, a critical component of romance. "When you inhibit this brain system," she warned, "you can inhibit your patient’s well-being and possibly their genetic future."
These antidepressants also inhibit orgasm, clitoral stimulation, penile erection ("the entertainment system, in my business"), and deposit of seminal fluid. From an anthropological perspective, a woman who can’t get an orgasm may fail to distinguish Mr Right from Mr Wrong. As one woman on an SSRI confided to her: "I thought I no longer loved my husband." In a study in press, women on SSRIs rated male faces as more unattractive, a process she calls "courtship blunting."
Seminal fluid contains dopamine and norepinephrine, oxytocin and vasopressin, testosterone and estrogen, and FSH and LH. Without an orgasm, said Dr Fisher, men lose the ability to send courtship signals. Said one man, who lost his motivation and self esteem as a result, "I just stopped dating."
Ironically, because antidepressants inhibit depression, patients may lose their ability to send an honest clear signal for social support and (for those with mild depression) lose the necessary insight to make hard decisions (the failure of denial factor).
Dr Fisher said she didn’t want psychiatrists to stop prescribing serotonin-enhancing antidepressants for their patients, but did stress the need to take the love-relationship picture into account.
See also: The Whole Sex Bipolar Thing
Revised June 29, 2016