The Molecule of More

“How’s Shawn?” said Samantha’s mother.
“Well . . . ,” Samantha traced the rim of her coffee cup. “This isn’t 
the way I expected it to be.”
“Again?”
“Here it comes,” said Samantha.
“I’m just saying that Shawn seems like a great guy—”
“Mother, I don’t want to play ‘count your blessings.’ ”
“This isn’t the first time. Remember Lawrence? And Demarco?” 
Samantha bit her lip. “Why can’t you enjoy the things you have?”

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16
THE MOLECULE OF MORE
THE CHEMICAL KEYS TO LONG-LASTING LOVE
From dopamine’s point of view, having things is uninteresting. It’s only 
getting things that matters. If you live under a bridge, dopamine makes 
you want a tent. If you live in a tent, dopamine makes you want a 
house. If you live in the most expensive mansion in the world, dopa-
mine makes you want a castle on the moon. Dopamine has no stan-
dard for good, and seeks no finish line. The dopamine circuits in the 
brain can be stimulated only by the possibility of whatever is shiny and 
new, never mind how perfect things are at the moment. The dopamine 
motto is “More.”
Dopamine is one of the instigators of love, the source of the spark 
that sets off all that follows. But for love to continue beyond that stage, 
the nature of the love relationship has to change because the chemical 
symphony behind it changes. Dopamine isn’t the pleasure molecule, 
after all. It’s the anticipation molecule. To enjoy the things we have, as 
opposed to the things that are only possible, our brains must transition 
from future-oriented dopamine to present-oriented chemicals, a col-
lection of neurotransmitters we call the Here and Now molecules, or the 
H&Ns. Most people have heard of the H&Ns. They include serotonin, 
oxytocin, endorphins (your brain’s version of morphine), and a class 
of chemicals called endocannabinoids (your brain’s version of mari-
juana). As opposed to the pleasure of anticipation via dopamine, these 
chemicals give us pleasure from sensation and emotion. In fact, one of
the endocannabinoid molecules is called anandamide, named after a 
Sanskrit word that means joy, bliss, and delight.
According to anthropologist Helen Fisher, early or “passionate” 
love lasts only twelve to eighteen months. After that, for a couple to 
remain attached to one another, they need to develop a different sort 
of love called companionate love. Companionate love is mediated by the 
H&Ns because it involves experiences that are happening right here, 
right now—you’re with the one you love, so enjoy it. 
Companionate love is not a uniquely human phenomenon. We see 
it among animal species that mate for life. Their behavior is character-
ized by cooperative territory defense and nest building. The bonded 

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LOVE
pair feed each other, groom each other, and share parental chores. Most 
of all, they stay close to each other and display expressions of anxiety 
when separated. It’s the same for humans. Humans engage in similar 
activities and have similar feelings, particularly satisfaction that there is 
another person whose life is deeply entwined with their own.
When the H&Ns take over in the second stage of love, dopamine 
is suppressed. It has to be because dopamine paints a picture in our 
minds of a rosy future in order to spur us on through the hard work 
necessary to make it a reality. Dissatisfaction with the present state of
affairs is an important ingredient in bringing about change, which is 
what a new relationship is all about. H&N companionate love, on the 
other hand, is characterized by deep and enduring satisfaction with the 
present reality, and an aversion to change, at least with regard to one’s 
relationship with one’s partner. In fact, though dopamine and H&N 
circuits can work together, under most circumstances they counter each 
other. When H&N circuits are activated, we are prompted to expe-
rience the real world around us, and dopamine is suppressed; when 
dopamine circuits are activated, we move into a future of possibilities, 
and H&Ns are suppressed.
Laboratory testing supports this idea. When scientists looked at 
blood cells extracted from people who were in the passionate stage of
love, they found lower levels of H&N serotonin receptors compared to 
“healthy” people, an indicator that the H&Ns were in retreat.
It’s not easy to say farewell to the dopaminergic thrill of new part-
ners and passionate longing, but the ability to do so is a sign of maturity, 
and a step toward long-lasting happiness. Think of a man who plans 
a vacation to Rome. He spends weeks scheduling each day, making 
sure he will be able to visit all the museums and landmarks he’s heard 
so much about. But when he stands among the most beautiful artwork 
ever created, he thinks about how he’s going to get to the restaurant 
where he has reservations for dinner. He’s not ungrateful to see the 
masterpieces of Michelangelo. It’s just that his personality is primarily 
dopaminergic: he enjoys anticipation and planning more than doing. 
Lovers experience the same disconnect between anticipation and expe-
rience. The early part, passionate love, is dopaminergic—exhilarating, 

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THE MOLECULE OF MORE
idealized, curious, future looking. The later part, companionate love, is 
H&N focused—satisfying, peaceful, and experienced through bodily 
senses and emotions.
A romance built on dopamine is a thrilling, if short-lived, roller 
coaster ride, but our brain chemistry gives us the tools to move down the 
path that leads to companionate love. Just as dopamine is the molecule 
of obsessive yearning, the chemicals most associated with long-term 
relationships are oxytocin and vasopressin. Oxytocin is more active in 
women and vasopressin in men.
Scientists have studied these neurotransmitters in the laboratory 
in a variety of animals. For example, when scientists injected oxytocin 
into the brains of female prairie voles, the animals formed a long-term 
bond with whatever male happened to be around. Similarly, when male 
voles that were genetically programmed to be promiscuous were given 
a gene that boosted vasopressin, they mated with one female exclu-
sively, even though other receptive females were available. Vasopressin 
acted like a “good-husband hormone.” Dopamine does the opposite. 
Human beings who have genes that produce high levels of dopamine 
have the highest number of sexual partners and the lowest age of first 
sexual intercourse.
Most couples have sex less frequently as obsessive dopaminergic 
love evolves into companionate H&N love. This makes sense, since oxy-
tocin and vasopressin suppress the release of testosterone. In a similar 
way, testosterone suppresses the release of oxytocin and vasopressin, 
which helps explain why men with naturally high quantities of testos-
terone in their blood are less likely to marry. Similarly, single men have 
more testosterone than married men. And if a man’s marriage becomes 
unstable, his vasopressin falls, and his testosterone goes up.
Do human beings require long-term companionship? There’s good 
evidence that the answer is yes. Despite the superficial appeal of hav-
ing multiple partners, most people eventually settle down. A United 
Nations survey found that more than 90 percent of men and women 
marry by the age of forty-nine. We can live without companionate love, 
but the majority of us arrange a good portion of our lives around trying 
to find it and keep it. The H&Ns give us the ability to do that. They 

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LOVE
allow us to find satisfaction in what our senses deliver—what is right in 
front of us, and what we can experience without the nagging sense that 
we need something more. 
TESTOSTERONE: THE HERE & NOW 
CHEMICAL OF SEXUAL ATTRACTION
The night Samantha first met Shawn, she was on day thir-
teen of her menstrual cycle. Why does that matter?
Testosterone drives sexual desire in both men and 
women. Men produce large amounts—it’s responsible for 
aspects of masculinity such as facial hair, increased mus-
cle mass, and a low-pitched voice. Women produce smaller 
amounts in their ovaries. On average, women have the high-
est levels of testosterone on days thirteen and fourteen of 
their menstrual cycle. That’s when the egg is released from 
the ovary, and they are most likely to get pregnant. There 
are also random variations from day to day and even within a 
day. Some women produce more testosterone in the morn-
ing, others later in the day. The largest variation is between 
individuals; some women naturally produce more than oth-
ers. Testosterone can even be administered as a drug. When 
scientists at Procter & Gamble (the maker of Old Spice 
cologne and Pampers diapers) applied a testosterone gel to 
women’s skin, the women had more sex. Unfortunately, some 
of the women developed facial hair, low-pitched voices, and 
male pattern baldness, so the “female Viagra” gel never 
received Food and Drug Administration (FDA) approval in 
the United States.
Helen Fisher, an anthropologist at Rutgers University 
and chief scientific advisor to the Internet dating site Match 
.com, points out that the type of sexual drive testosterone 
produces is similar to other natural urges, such as hunger. 

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THE MOLECULE OF MORE
When one is hungry, all kinds of different foods will sat-
isfy the urge to eat. Similarly, when a person experiences 
testosterone-induced sexual urges, the desire is for sex in 
general, not necessarily for a particular person. In many 
cases, especially with young people, nearly anyone will do. 
Neither is it an overwhelming desire. People don’t die from 
sexual hunger. Testosterone doesn’t drive them to commit 
suicide or murder—unlike the dopaminergic experience of 
being overwhelmed by love.