I include here Professor Castillo's lesson about Romantic Love.
I. LUST PHASE
The first stage is LUST. This is the primordial drive for sex and is essentially driven by levels of the hormone testosterone. Both genders have testosterone, males, obviously, have more of the hormone. As testosterone levels increase, sexual desire increases and vice versa. Male libido tends to peak in the 20’s and decline during middle and old age. Women’s libido, although not as high as men’s, does not statistically decline in middle age because as estrogen levels diminish, it unmasks the latent testosterone hormones. (18) Lust does not seek a mate but a physical encounter.
II. ROMANTIC LOVE PHASE
ROMANTIC LOVE is the phase of love that Plato called “a madness”. It makes us giddy and gives us high energy and causes obsessive behavior. The current research has shown that individuals in the stage of romantic love have unusually high levels of several chemicals. They are (1) phenylethylamine, (2) dopamine, and (3) norepinephrine. What do each of these chemicals do to us? In short, they produce in us the symptoms observed and experienced in those who are madly and passionately in love. Gentlemen, now let’s briefly look at each of these chemicals one at a time that are associated with romantic love.
Phenylethylamine, or PEA for short, is often referred to in the lay press as the “love molecule.” It is essentially a natural form of amphetamine that our body produces. The molecule is thought to speed up the flow of information between nerve cells. Writers of romantic love often describe lovers as being shaky, prone to insomnia, as well as having increased energy and poor appetite. Increased respiration and heart rate are also common when one is near the one the lover desires. As Elvis Presley sang, when one is in love, one really is “all shook up.” This physiological state is caused by high levels of PEA. Interestingly, one sees similar symptoms in people who are high on amphetamines. High levels of the chemical PEA have been well documented in people who are in the initial throws of the romantic infatuation phase of love. But, PEA levels do tend to diminish over several years after one “falls in love”. (19)
The second and most important chemical that researchers have found elevated in romantic love is dopamine. It is a member of the chemical family that is the precursor to epinephrine, often called adrenaline by laymen. In the brain, dopamine acts as a neurotransmitter. It is also a neuro-hormone released in the part of the brain called the hypothalamus. Dopamine is important in allowing the body to move. A shortage of dopamine causes Parkinson’s disease. But dopamine also, as Dr. Crenshaw states, “…mobilizes you to recognize, seek and pursue pleasure.” (20) The new research on love has shown that dopamine is elevated in those smitten with love. In addition, dopamine stimulates sexual desire by raising testosterone levels. For that reason, Dr. Fisher refers to dopamine as the “liquor of romance.” (21) Dr. Crenshaw elaborates further:
Dopamine takes you on an emotional high…it is especially desirable and addictive…(it) is the common denominator in most human addictions from drug abuse to hypersexuality…(22)
In short, the “high of love” is physiologically very similar to the high of drugs such as amphetamines and cocaine.
Closely related to dopamine is the third romantic love chemical called norepinephrine also a form of adrenaline. It is produced in the adrenal glands. It is also a neurotransmitter in the brain. Like PEA and dopamine, norepinephrine also increases testosterone levels. This chemical is a stimulant and lower brain levels of it seem to be correlated with depression. We all know, gentlemen, smitten lovers have high energy levels and are exhiliarated. Just recall Oscar Hammerstein’s lyrics in the song “Hello Young Lovers”:
I know how it feels to have wings on your heels
and to fly down the street in a trance,
You fly down the street in the chance that you meet
and you meet, not really by chance.
This sensation of “wings on your heels” may be due to norepinephrine’s stimulation of the sympathetic nervous system. As Dr. Fisher states, “…increasing levels of this simulant generally produce exhilaration, excessive energy, sleeplessness, and loss of appetite—some of the basic characteristics of romantic love.” (23)
As you can see, gentlemen, the new research on the physiology of love actually supports the Hippocratic model, namely that when one is in love, there is a change or imbalance in chemical levels, specifically in the brain. Once one finally finds that special someone and falls in love, the levels of phenylethylamine, dopamine, and norepinephrine increase as compared to the levels in those not in the throws of romantic love. All of these three chemicals have the further hormonal effect of raising testosterone levels thereby increasing libido. As all these “love potion juices” flow, they cause the symptoms and behavior of those who are smitten with love.
Research has gone even further. Using the new technology of functional MRI, neuroscientists are able to visualize which parts of the brain are active at any given time. And the critical question that needed to be answered is the following: Are the areas of the brain associated with the dopamine centers more active in those individuals in love than those who are not in love? The short answer is a resounding “yes”!
In the year 2000, two distinguished British neuroscientists, Bartels and Zeki, performed functional MRIs on 17 students who reported being madly in love. The study compared the MRIs when the lovers were shown pictures of the faces of their lovers in contrast to the MRIs taken when they were shown faces of just their friends. The results showed that when the subjects were shown their beloved’s face, the area of the brain called the caudate nucleus “lit up”. (Figure 2) And, gentlemen, the caudate nucleus is the area where 80% of the brains receptors sites for the neurotransmitter dopamine reside. Of note, it is also the area of the brain that is involved with cocaine and drug induced euphoria. The researchers concluded something that all lovers know, namely, that there is “…a close neural link between romantic love and euphoric states.”(24)
Importantly, the study also showed that the areas of the brain activated in romantic love are very distinct from those areas of the brain that are activated with sexual arousal (25) correlating nicely with Dr. Fisher’s three divisions of love, namely, LUST, ROMANTIC LOVE and LONG TERM ATTACHMENT. Bartels and Zeki conclude their paper in poetic prose most unusual in scientific papers:
By showing that a unique set of interconnected areas become active when humans view the face of someone who elicits a unique and characteristic set of emotions, we have shown that underlying one of the richest experiences of mankind is a functionally specialized system of the brain. It is perhaps surprising that so complex and overwhelming a sentiment should correlate differentially with activity in such restricted regions of the brain… (26)
Further functional MRI studies collaborating their findings have been done by Drs. Fisher, Brown and Aron. They also showed that the caudate nucleus was highly active when those in love viewed the pictures of their lovers. In the words of Dr. Fisher:
…our most important finding was activity in the caudate nucleus…the more passionate…the more active (the) caudate.(27)
Along with activity in the caudate nucleus, Fisher’s research found high activity in another area of the brain rich in dopamine producing cells called the ventral tegmental area or VTA for short. (Figure 2) (28). The most important point is that the areas of the brain most active in ROMANTIC LOVE are the dopamine centers. However, since the caudate nucleus is so active in lovers, Fisher refers to it as “the furnace of romantic love.” (29)
III. LONG TERM ATTACHMENT PHASE
Finally, gentlemen, a few brief comments about the third phase of love called LONG TERM ATTACHMENT. Does it also have an imbalance of chemicals at play and are there specific areas of the brain activated with it? The answer to both is “yes.” Recent research has shown that two neurohormones, oxytocin and vasopressin, are elevated in those who have been bonded in love for many years. Oxytocin is released in women during childbirth and lactation and research has shown that this chemical helps the mother to bond emotionally to her newborn. And vasopressin has also been shown to be critical in long term bonding in rodents and primates. (30) During intercourse, these chemicals are released in both genders with breast and genital stimulation as well as with orgasm. (31) Oxytocin has also been shown to be released even when humans hold hands or “snuggle,” resulting in its referral in the lay press as the “cuddle hormone”. In short, with each erotic moment with one’s beloved, nature is bonding the couple tighter and tighter by elevating the oxytocin and vasopressin levels. Wanderlust, by contrast, is suppressed because testosterone levels are driven down when oxytocin and vasopressin levels rise. (32)
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