Review of "Hooked: New Science on How Casual Sex is Affecting our Children."-Chapter 2 (part 3)

Last time we discussed Oxytocin and its roll in female pair-bonding.  Chapter 2 concludes with a section on Vasopressin, a close relative of oxytocin and its effects in males.

Vasopressin

Vasopressin

Arginine vasopressin (AVP), commonly known as vasopressin is a hormone that performs many regulatory functions in mammals.  It helps maintain homeostasis by controlling water retention and permeability of various barriers such as blood vessels and certain kidney tissues.

What's of more interest to us today is its potential effects on the brain.  Vasopressin has been implicated in partner selection and bonding in some mammals, though the evidence is scant at this point for a causal link as we shall see.

Hooked paints a much stronger picture of the relationship between the hormone and bonding.

"Women are not the only ones who bond during intimate physical contact.  The neurochemical responsible for the male brain response and synaptic change is called vasopressin. ...Vasopressin seems to have two primary function related to relationships-bonding of the man to his mate and attachment to his offspring. ...Often referred to as the 'monogamy molecule' vasopressin seems to be the primary cause of men attaching to women with whom they have close and intimate physical contact."-Hooked pg. 41 (emphasis added)

Often referred to by whom I wonder? All the references I've found online to 'monogamy molecule' point to Hooked or blogs of similar ideological bent.  Let us be generous though and consider the evidence they present. Don't worry, it won't take long.

On the next page we find that their only source for their claim that vasopressin is "responsible for the the male brain response" is a small series of studies in prairie voles.  In fact, the same prairie voles are at the core of their arguments for oxytocin bonding as well.  I already discussed the problems with generalizing from animal studies to human psychology in Chapter 2 (part 1), so I won't repeat myself except to again recommend this article by Stacy Schiff on the subject.

But a closer look at these studies gives us less reason to support the claims of Hooked rather than more. First, not all prairie voles in the studies are in fact monogamous, and moreover biologists don't even mean the same thing by monogamy.

Consider this excerpt from "Monogamy and the Prairie Vole" by Carter and Getz.

"...although common in birds, monogamy is rare in mammals.  In an exhaustive survey, Devra G. Kleiman of the National Zoological Part in Washington, D.C., found that only about 3 percent of mammals are monogamous.  Sexual exclusivity, however, is not a feature of monogamy.  Studies of the prairie vole as well as those of other mammals and birds have indicated that absolute sexual monogamy is not necessarily associated with social monogamy.  In fact, DNA fingerprinting tests have shown that offspring of female prairie voles are not always fathered by the cohabiting males.  In some cases, a litter may have mixed paternity."  

While only 3% of mammals monogamous, all have oxytocin and vassopressin.  Oxytocin and vassopressin likely play a role in bonding but it is unscientific and overly simplistic to claim either of them are the cause.

More importantly though, the "monogamous" prairie voles sleep around.  The paragons of rodent fidelity are clearly not as virtuous as Hooked purports them to be.  Clearly an overabundance of oxytocin and or vasopressin mixed with "casual sex" has not impaired the voles' ability to pair bond in the slightest.

Pheromones
The last chemical influence mentioned in the chapter, however briefly, is human pheromones.  Their claims about pheromones are much more reserved and appropriately so.

Research has revealed that pheromones are involved in a woman's sexual attraction for a specific type of man.  We also know that pheromones are involved, to some unknown extent, with a woman's sexual satisfaction with a man.-Hooked pg. 44

The evidence for human pheromones is sketchy at best.  The papers used to support this claim do suggest that a man's odor has an impact on a woman's sexual attraction.  However, pheromones and odors are not identical.  Pheromones are used by many animals to communicate, especially during the wondrous activities leading to procreation.  Pheromones excreted by one animal are detected by the other using the vomeronasal (Jacobson's) organ.

Unfortunately for proponents of the human pheromone hypothesis, the vomeronasal organ is atrophied and non-functional in humans.

So what's the point of all this?

Stepping back from the scientific details to examine the larger themes of this chapter, we notice a clear trend.  Chemicals at work within your body conspire to destroy your ability to bond with your future (opposite-sex) spouse if you decide to have sex with anyone else in your life.

The authors even put forth this rather curious analogy:

Their inability to bond after multiple liaisons is almost like tape that loses its stickiness after being applied and removed multiple times. -Hooked pg. 43

Imagine for a second that this was true: that oxytocin  forms a partial bond with whoever triggered it and consequently weakens each successive bond.  What would such a world look like?  Mothers who cannot breastfeed or delivered by Cesarean would be less able or unable to bond with their children.  Our loving grandmothers, well beyond menopause, would display a decreasing ability to bond.  Massage therapists would be unable to maintain committed relationships because they bonded with every one of their customers, and their customers would be increasingly unfaithful to their own partner with each visit.  Mothers delivering multiple children would be less able to bond to their latter children.  People who have and care for pets would likewise be less able.  And most interestingly, people who live in blue houses would be destined to never marry.

Is this the world we live in?  Do these implications mesh with our experience? Clearly not.

What is far more interesting than the implications of this idea is its origins.  The tape analogy provides a clearly traceable fingerprint leading back most proximally to Dr. Eric Keroack.

Dr. Eric Keroack
Dr. Keroack was an OBGYN in Massachusetts who acquired great fame in conservative circles promoting abstinence as a public health measure.  Until around 2006 he presided as the medical director of a pro-abstinence organization called "A Woman's Concern" that opposed contraception and suggested that condoms "offer virtually no protection" against herpes or HPV.  But the claim he is most famous for is the central thesis of Hooked: premarital sex disrupts brain chemistry making happy marriages more difficult.

Despite (or more likely in light of) the scientific failings of Dr. Keroack's beliefs, in 2006 he was appointed as the Deputy Assistant Secretary of Population Affairs in the Department of Health and Human Services by then President George W. Bush.  The Bush administration unilaterally gave Keroack the position, from which he would oversee all federally funded family planning programs.  Fox, meet hen house.

Keroack's influence is pervasive in Hooked.  Much of the claims he first popularized are repeated here verbatim   Let's examine the similarities.

Keroack calls oxytocin "God's Super Glue." He believes abstinence is the best form of birth control and says that women who engage in premarital sex can wear out their oxytocin response.

"People who have misused their sexual faculty and become bonded to multiple persons will diminish the power of oxytocin to maintain a permanent bond with an individual."-Keroack

He even appears to have originated the tape analogy itself.

Extrapolating in part from research with prairie voles, which are monogamous, he postulates that oxytocin cannot survive too much sex, at least with multiple partners, at least prior to marriage. By way of demonstration he proposes the duct tape test: you need only an adhesive and a hairy arm. The tape represents the brain. Press it down. Now reapply. See what happens? Less sticky, right? Concludes Keroack: “Basically, you will end up damaging your brain’s ability to use the oxytocin system as a chemical mechanism that serves to help you successfully bond in future relationships.”-Link

In 2001, Keroack co-authored a paper with Dr. John Diggs for a group called the Abstinence Clearinghouse. The report concluded:

"People who have misused their sexual faculty and become bonded to multiple persons will diminish the power of oxytocin to maintain a permanent bond with an individual. . . . Just as in heroin addiction . . . the person involved will experience 'sex withdrawal' and will need to move on to a . . . new sex playmate."

Reportedly, the citation given in the paper was a 1999 preliminary study by Dr. Rebecca Turner, a researcher at California School of Professional Psychology (CSPP) at Alliant International University.

Fortunately, we have Dr. Turner's rebuttal to Keroack's "complete pseudoscience" misrepresentation of her work.

"In any case, none of our studies provide a basis for their claims," Dr. Turner averred. Keroack did not cite any of Turner's later, more definitive work. 

"Scientific research has shown that the hormone cortisol rises with psychologically-induced stress," Dr. Turner explained. "Our research examined whether blood levels of oxytocin would similarly increase with sad or positive emotions induced by interview discussions and emotionally-evocative film clips. The research was a collaboration between CSPP and the University of California San Francisco (UCSF), and was funded by the National Institutes of Mental Health in 1998. Margaret Altemus, MD, a psychiatrist at the Weill Medical College of Cornell University, was Co-Principal Investigator for the studies. The initial study was cutting-edge research at the time; but, in the end (2002), we did not find changes in oxytocin levels that were related to these emotions."   

At least Dr. Keroack's co-author did acknowledge that they were developing conclusions that no scientists would ever put forth."

Link

If the original author of the research decrying his conclusions was insufficient, consider the words of another prominent critic of Keroack's work: Dr. Jill Schneider .

He has the results of the animal studies somewhat garbled. He's spreading misinformation about the studies themselves. Then, his extrapolation to humans is also unfounded. Keroack is using something he learned about oxytocin and bonding, and fabricating a story that somehow premarital sex would release oxytocin and prevent a woman's ability to form a long-term pair bond in marriage. 

It's basically medical misinformation to say that the only healthy human relationship is monogamous marriage. Clearly, there are healthy single people and healthy people who practice serial monogamy. The United States is full of all types of healthy families.

For example, oxytocin is released during childbirth and breastfeeding and orgasm. If a mother experiences this great oxytocin release with her first child, there's no evidence that it would cause her to bond exclusively with that child. She certainly has the ability to welcome the next child and the next one. So, why would this guy think that oxytocin going up during premarital sex would prevent a healthy pair bond during marriage?

Link 

Dr. Keroack's hypotheses on oxytocin are not supported by the scientific community at large or by the producers of the original research they're based upon.  Despite this, Hooked continues to pass the claims on as verified scientific fact.  Moreover, they suggest very strongly that our brains were in fact designed to punish us for infidelity.

"Taken as a whole, these complicated processes offer a compelling pattern. They are designed to lead toward and strengthen long-term monogamous relationships, supporting and reinforcing the family structure that is so vital to our survival."-Hooked pg. 45

Again and again Hooked points towards a sort of overarching design of our neurochemistry.  The designer they imply is not merely the "values neutral" blind watchmaker of natural selection, but a value laden fully intentional designer who wanted us to be monogamous.

Despite their claims to be scientific in their endeavors, the authors of Hooked have strayed well off the scientific reservation and into the perilous lands of intelligent design.  It is at this point that I abandon all hope of their return.


Previous: Chapter 2: Meet the Brain (Part 2: Oxytocin)
Next: Chapter 3: The Developing Brain and Sex
Table of Contents