This Is Your Brain on Sex (23 page)

Daddy Brain

So far I have limited the discussion to mothers. It is the primary focus of research in this vein—though, I’ll admit, being a mother myself, I have something of a bias. Given that my bodily investment in the birth of my child was a wee bit more time-consuming (not to mention stretch-mark-inducing) than my ex-husband’s, I tend to snort when I hear about sympathetic pregnancies and the like. I can’t help it. With pregnancy making so many physical changes to my body, it seems perfectly logical that it would alter my brain too. But it is hard to imagine that the brains of expectant fathers would also be affected. Yet new research is discovering that men’s brains may also go through some changes once they become fathers (or are made responsible for the care of a child). They may not be the same as those changes that happen in mothers (and I’m tempted to add a snarky “not even close”), but these changes happen nonetheless.

As stated before, prairie voles are alloparental: like moms, dads, sisters, and brothers share in the caregiving. While some virgin females may be a bit
eh
when it comes to pups, sexually immature males get a surge of oxytocin when they are exposed to the little guys. This boost allows them to pair-bond faster when they mate and to become more attentive fathers. If the underlying hypothesis is correct, that oxytocin is mediating some of these changes to the brain, then these lifts likely work some magic on the male brain too.

When Ruth Feldman looked at oxytocin levels across pregnancy and the postpartum period, she did not stop with the moms. She studied the levels of both new moms and
new dads soon after birth and then at six months postpartum. And again she had trained observers take a look at parental behavior. The study yielded some interesting findings. First, the oxytocin levels of the fathers looked a heck of a lot like those of their partners during both measurements. Even though birth and lactation helped to push Mom’s level up, something was working the same sort of effect in Dad without requiring an epidural. It hardly seems fair.

Second, not only did parents show similar oxytocin levels, but those respective levels were correlated to a gender-specific parenting style. Moms with high oxytocin levels cuddle, coo, and look longingly at their baby. Dads with these levels, however, tend to be more playful and stimulatory, and encourage exploration and interaction with toys. Is this biology or some sort of societal influence? No one can say for sure. It does suggest, however, that oxytocin levels are changing Mom’s and Dad’s brains in a variety of ways—and in such a manner as to facilitate different kinds of parenting behaviors.
¹⁴

These parenting-style results were further substantiated when Feldman and her colleagues measured oxytocin levels in moms and dads with four- to six-month-old infants after a fifteen-minute play session. The levels were highly correlated across each parent couple. But moms who were über-affectionate with babies showed a significant bump in oxytocin after the play session. Dads, however, showed this increase in the neuropeptide only when they engaged in more physical, stimulatory-type play—you know, the rough-and-tumble type. The group hypothesized that moms and dads have evolved to fulfill different needs in children. And, as was found in epigenetic studies, that early childhood experience has the power to shape neurobiological development when it comes to love and attachment.
¹⁵

It is easy to suggest, especially for us moms, that there is something unique about a maternal bond, that the postpartum brain provides the right substrate for a singular and loving attachment you cannot find anywhere else. That does not, however, diminish the father’s role—or that of a grandmother or an adoptive parent or even perhaps a sister or uncle. At the end of the day whoever is offering love and care to a child is likely to be undergoing some changes to the brain that help to cement the bond.

When I spoke with Karen Bales, a neuroscientist
at the University of California, Davis, who studied the maternal bond in a variety of species, about whether there was something neurobiologically distinct about a mother’s love, she asked me if I knew about the parenting style of titi monkeys (
Callicebus cupreus
), a species of monkey that is monogamous and alloparental. I revealed that I did not. “Essentially,” Bales told me, “titi monkeys have a selective attachment to their fathers rather than their mothers. They get a stress response from being separated from their dads; they go to their dads for comfort. I think the idea really is that whomever you grow up having contact comfort with is [the] one you’ll have a special attachment to, and that is somehow manifested in the brain. It’s the norm in many species to have a special attachment relationship with your mother, but there is no reason to believe that you couldn’t have that same kind of relationship with whoever your caregiver happens to be.”

I could see that this makes sense. After all, we know that environment is an important variable in developing and maintaining a social bond. When it comes to parenthood, a baby is more than just offspring, it is a learning reinforcement in its own right. One’s interactions with an infant play a role in many of the brain changes seen in parenthood. In a pair-bonded couple, brains may change in such a way that moms and dads take on varying parenting strategies. It’s just as easy, however, to make the argument that in a situation with two dads (or two moms, or a mom and a grandma, or a dad and an uncle—whatever combination fits a particular family), you’ll see a similar division of brain labor, so to speak. Given what we know about the brain’s plasticity, there is no reason to think the experience of parenting wouldn’t change the brains of adoptive, step-, or foster parents too. The only thing I believe we can say with certainty is that there is still a lot to learn. Honestly, at times the research seems to provide a heck of a lot more questions than answers.

As it stands, the neurobiology of parenting, like that of love and sex, is still in its infancy. There are still many questions to be asked (and answered) about how the brain changes after parenthood and what neurochemical systems may be mediating those changes.

If I’m being honest, no matter what neuroscientists may uncover, they aren’t going to change my thinking about my own motherhood experience. No matter how clever or elegant
their studies may be, they’ll never affect how much I adore my son. As I told you, my feelings are inviolate (and, if Semir Zeki is right, those feelings are supported by a push-and-pull system between my frontal lobes and the brain’s reward systems). So whatever the future of this field may bring, I’m going to continue to think my kid is so sexy as to merit banning. I will know in my heart that our bond is like no other. And that’s more than enough for me.

Chapter 10

Might as Well Face It, You’re Addicted to Love

Turn on the radio at any
time of day and chances are you will find a love song playing. It’s going to happen whether you are keen on opera, heavy metal, or alt-rock—love is memorialized in song, regardless of genre, more than any other topic. Though any one love song may have its own particular quality, there is a lot of overlap when it comes to the themes explored. One that frequently comes up is the idea of love as an addiction.
Your love is my drug.
I can’t kick the habit
.
I don’t know why I can’t get enough of your love, babe
.
I don’t want no cure
.
I got to have all your loving
.
I can’t let you go.
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I could go on, but you get the idea. There’s something about love that tends to make one feel like a crackhead.

Addiction, loosely defined, is the unshakable compulsion to seek out and indulge in a substance like alcohol or drugs, despite the adverse and detrimental consequences that usually go with it. It’s a condition that never fully goes away, although it can be treated and may decrease in power over time. Once you give up that substance, you’ll suffer physical, perhaps even emotional and mental, withdrawal symptoms. Even if you learn strategies to avoid using, you will still suffer from cravings, and no matter how long you stay clean, you always run a risk of relapse. It’s a sticky, messy business.

Though there has been extensive neurobiological study of drug addiction, its etiology, or medical cause, is still not well characterized. What neuroscientists can tell you is that drugs influence the neurotransmitter and receptor systems in the mesocortical limbic system, our reward processing system. Cocaine,
for example, blocks the reuptake of dopamine by neurons, giving you that rush of feel-good, albeit manic, energy. The variable (or variables) that causes one person who uses drugs to have just a high old time every now and then while creating a chronic user out of another is still unclear. Somehow the mixture of a genetic predisposition, the social and psychological environment, and repeated tokes of a favored substance leads to the disorder. Makes you wonder—despite all those pop song warblings about love being an addiction, does it actually meet the criteria?

Consider my friend Tasha, who is currently in the throes of love. Tasha’s world has started to revolve around her love, eclipsing everything else that was once important to her. Her other personal relationships have suffered since she started dating this guy: she doesn’t have much time or patience for anything other than her love. She admits to feeling a physical rush when seeing the object of her love, complete with a racing heart and sweaty palms. When she’s away from her love, she misses his presence and his touch. That seems to manifest itself in a physical manner too. She
craves
love. Tasha says the sensation she has when she is with her love is like nothing else on earth. She spends too much money on love, risks her standing at work for love, has argued with family and friends for her love, and has made a few poor life decisions because of love. If she were to be rejected by her love, resulting in his full withdrawal from her life, she would be emotionally despondent, perhaps even physically sick.
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Tasha’s friends have even worried that this single-mindedness may have the power to put her in harm’s way. What started as something positive and oh-so-good-feeling has changed in Tasha; this love of hers now often appears as a preoccupation and a collection of somewhat destructive, compulsive behaviors. As you can see, this love has a lot of power over her.

Now go back and replace the word
love
in the previous paragraph with
heroin
or
cocaine
. Love, requited or not, can turn even the most stalwart of us into stereotypical junkies.

Full disclosure: there is no Tasha. I made her up. However, I could put the name of more than a few of my friends in the paragraph above. I would venture to say most of us have felt that overwhelming crazy-in-love feeling for at least one person in our lives, perhaps more than one. We have experienced
a love that had the power to make us feel our very best and yet could turn us into the very worst version of ourselves. There’s no need to pick on just one of my friends to illustrate the concept.

Sometimes this addiction-like behavior doesn’t even involve love per se—just unbelievable, world-rocking sex that ended up holding way too much sway over one’s life. In fact I’d wager many of us have also found ourselves inexplicably drawn to a sexual partner whom we did not even like all that much as a person. It happens to the best of us. Even though this situation may include only I-want-to-rip-your-clothes-off lust and bears no resemblance to love, it also has the power to compel you to do things you would not (and often should not) normally do.

Usually these irresistible and overpowering feelings, whether love or lust, mellow over time—hopefully before you do too much damage to your life. The sensation may morph into a strong feeling of attachment or blow up into the unhappiest of endings. We tolerate our friends (and perhaps ourselves) while in the throes of this crazy love because we intrinsically know this too shall pass. At least, we hope so.

But for some, the feeling does not pass. That love itch can never be scratched quite enough. An acquaintance of mine, Kristie, joined a twelve-step recovery program three years ago. Her drug of choice was not heroin or alcohol; she didn’t smoke crack or shoot up methamphetamine. No, her compulsive behaviors had everything to do with sex and love. “Before recovery, when I was with a man, it felt like a dream. I was never really present, it was like I was floating above any situation when we were together, feeling physically high,” she told me. “When a guy flirts with me, any guy flirts with me, I feel an actual physical high. Like I just got a hit of cocaine. In recovery, we call that ‘the intrigue.’ And before I got help, I’d feel that hit and do whatever I could, even putting myself in dangerous situations, so I could feel it again.”

Currently the
Diagnostic and Statistical Manual of Mental Disorders
(
DSM-IV
) does not include any mention of sexual or love addiction. Kristie diagnosed herself once she recognized the toll her sex addiction was taking on her life. She then sought out a recovery program based on the popular Alcoholics Anonymous model. To date all addictive disorders listed in the
DSM-IV
involve actual substances, not so-called nonsubstances such as gambling, eating, or sex.
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