Hug the Monkey

Are Women More Likely to Forgive (and Forget)?

Still another fascinating human oxytocin study was published last week. Adam Guastella, from the Brain & Mind Research Institute, University of Sydney, gave 69 men a whiff of oxytocin and then showed them photos of faces. Some of the faces were happy, some neutral, some angry.

The next day, they showed the men some of the same photos mixed with new ones -- sans oxytocin. They asked them which ones they remembered; the men who had inhaled oxytocin were more likely to remember the smiling faces.

Adam Guastella also is doing a trial using oxytocin during couples psychotherapy, to see if it makes the couples more open and connected, thereby increasing the progress they make. Beate Ditzen did an experiment a couple of years ago in which couples snorted oxytocin and then engaged in an argument. Those who got oxytocin were better able to resolve the dispute with less anger.

At LiveScience.com, Meredith Small reports on the study in a post with the provocative title, How Birth Control Lets Us Down. Her premise is that because lactating seems to be the state in which we release the most oxytocin, when women don't have children or have fewer of them, we're missing out on the positive emotional benefits:

...the oxytocin universe has altered for many women. In Western culture today, women barely lactate at all, leaving them just as physiologically ready to hold a grudge, to never forget the face that did them wrong, as any man.

Too bad. Perhaps what we need is more lactation, by men and women, or a daily shot of oxytocin to help us all put on a happy face.

Of course, oxytocin is released in response to all sorts of social interactions. And, while estrogen seems to enhance its effects, making women more open to bonding or to forgetting those angry faces, men certainly fall under its influence as well.

Small makes another interesting and very important point, though: In situations or cultures where women do tend to be the ones to center the family and maintain social connections, this skill is not always valued:

Problem is, those good social skills, that penchant to forget the faces of those who are angry or neutral, has not always helped women. Instead, men, who are never awash in oxytocin and who apparently never forget an angry face, usually see women as emotional Pollyannas, silly creatures always ready to forgive and forget.

Of course, she is engaging is some stereotyping. Women certainly hold grudges, sometimes better than men, perhaps because a breach of the social bond is more devastating. And men are certainly awash in oxytocin, although their neurochemistries can make its effects less obvious.

See "Oxytocin enhances the encoding of positive social memories in humans."

Studying the Relationship Between Pitocin, Labor and Behavior

The Joy in Birth blog posted a summary of a very interesting study of whether the administration of pitocin during labor affects a child's later behavior.

As her Ph.D. thesis, Claire Winstone devised a survey to see whether the personalities or behaviors of three-year-olds differed based on whether their moms had pitocin or not. She found two distinguishing characteristics:

The first was called "Assertiveness" , which describes a socially appropriate way that babies and children communicate their need for help and comfort when they are feeling uncomfortable or unsafe. ... babies born with Pitocin, whose mothers reported having had a more challenging time during labor and delivery, appear to have a higher need to be assertive because they seem to experience more discomfort, but are apparently less effective in asserting their needs and getting them met when they feel unsafe or uncomfortable.

The second factor was called "Need to Control Environment" and this summarizes what seems to be a higher level of discomfort or insecurity, particularly in response to "outside-in" influences (e.g., reacting to food with digestive problems or being picky eaters; problems coping with other people's timing and structure, refusing help from others) and increased or exaggerated efforts to control their environment.

Blog author FairyMom doesn't provide a link to the study or information on who Winstone is; I think she may be this prenatal psychologist. In any case, the synopsis of her study is worth reading on the blog.

How Breastfeeding Helps Mothers Bond

Scientists at Warwick University have modeled the way breastfeeding creates an oxytocin feedback loop that creates the waves of love and peace that many mothers report enjoying while they suckle their babies.

According to the the UK's Mail Online,

... the research team, led by Warwick University scientists, has shown using computer models that when a baby suckles, the mother's neurons respond by churning out the hormone from their dendrites - the part of the cell that usually receives, rather than transmits information.

This extra release of oxytocin creates much stronger links between nerve cells - creating a 'positive-feedback' loop, where the greater the concentration of the chemical, the faster it is produced.

This allows massive, intense, bursts of the love hormone to sweep through the brain at intervals of around five minutes. The findings could shed light on other chemical changes in the brain linked to mood.

Professor Jianfeng Feng, who demonstrated the effect, said: 'We knew that these pulses arise because, during suckling, oxytocin neurons fire together in dramatic synchronised bursts.

'But exactly how these bursts arise has been a major problem that has until now eluded explanation.

This must be an amazing feeling, and I can see how it would create a very deep connection to the baby. I think those of us who haven't experienced this cannot imagine the feeling. I also have to wonder -- just a little? -- about how not experiencing this affects the bonding between mother and baby.

See also, The Mother/Baby Attachment Gap.

A Paradoxical Reaction to Oxytocin?

A new blog from Alia Macrina Heise identifies a syndrome she calls depressive milk ejection reflex, or D-MER. She defines it thus:

"Depressive Milk Ejection Reflex is a condition that causes a prodromal effect of negative emotions that emerge only before the milk ejection reflex, or letdown, in a lactating mother."

According to her blog, she's the mother of three -- and a lactation counselor. Although breastfeeding is supposed to be a peak experience -- deeply rewarding, sensual and soothing, thanks to oxytocin -- she experienced something quite different.

Go to her blog, D-MER.org, to read more about her experiences and those of other women.

One theory Alicia has for the cause of this syndrome, which involves discomfort and depression during breastfeeding, is a paradoxical reaction to oxytocin. A paradoxical reaction is when someone has not the expected reaction to a drug, but a different one, often the opposite.

I would guess that, rather than a paradoxical reaction to oxytocin, D-MER might be caused by an excess of prolactin. Prolactin is involved in milk letdown, but it's also involved in sexual satiety. It's the hormone, released at orgasm, that tells our bodies we've had enough sex, so give it a rest.

People sometimes talk about a feeling of letdown following sex, a sense of depression and even of distaste for one's partner. I think this, too, is the result of a bit too much of prolactin's satiating ability. It makes sense to me that an excess of prolactin, or too intense a response to its effects, could be the cause of D-MER.

Here are studies indicating prolactin's effect on sexual satiety:

Krueger, Tilmann H.C.; Haake, Philip; Hartmann, Uwe; Schedlowski, Manfred; and Exton, Michael S., Orgasm-induced prolactin secretion: feedback control of sexual drive? (Neuroscience and Biobehavioral Reviews 26 2002) 31-44)

Krueger, Tilmann H.C.; Haake, Philip; Haverkamp, J.; Krämer, M .; Exton, Michael S.; Saller, B; Leygraf, N.; Hartmann, Uwe; and Schedlowski, Manfred, Effects of acute prolactin manipulation on sexual drive and function in males (Journal of Endocrinology (2003) 179, 357–365)

Oxytocin Therapy for Indifferent Moms?

Oxytocin is being tested as a treatment for autism and social phobia, and it's under consideration for treating a variety of other disorders.

What about a mother who doesn't love her baby enough?

Despite the myth of the absoluteness of mother love, many new mothers don't feel attached to or excited about their newborns. There are myriad reasons for this, from the mother's inability to attach to anyone -- because of her own abuse or neglect as a child -- to a problematic or stressed pregnancy to that poorly understood neurochemical state known as post-partum depression.

Craig Kinsley, Professor of Neuroscience at the University of Richmond's Department of Psychology, has shown, in research with Kelly Lambert, how motherhood remodels the brains of rats. It increases the number of oxytocin receptors, increases the sensitivity of the receptors and also improves their memory.

Kinsley has begun to apply this research to human mothers. At the International Congress on Women's Mental Health, he suggested that this  research could lead to  interventions  aimed at helping new moms form a  secure bond.

According to the article in News in Science,

It may be possible, he says, with this template to then identify potential 'bad' mothers by examining how their brains behave when the mother is first interacting with the baby.

Kinsley says if females with a deficit of a critical neurochemical, such as oxytocin, can be identified, then "when they are first interacting with the baby you can give them a boost of oxytocin at a critical time".

The Women's Bioethics Blog predicted  this back in August 2007. See my post, Will Bad Mothering Become the Latest Disorder?

Kinsley's collaborator, Kelly Lambert, has found that fatherhood creates changes in the brains of male deer mice, as well. Maybe they could also give oxytocin to deadbeat dads.

Try the Middle Ground between Natural and Hospital Birth

Many things about a hospital birth have the potential to rupture or impede the first bonding between mother and child. For example, epidurals and anesthetic do seem to get into the baby's blood stream, so that both mother and baby are groggy and sickish following the birth. Babies delivered without anesthetic are alert and soon naturally begin to look for the breast, stimulating the release of oxytocin in mom and, likely, in baby.

Some think that the steady drip of pitocin, an artificial form of oxytocin, given to the laboring woman can create a sort of allergic reaction, or oversensitivity, in the baby. Later, according to this theory, that child may reject experiences that cause the oxytocin release. Some people think this may be part of the explanation for autism.

In any case, this article from Mother Earth News lays out a middle ground. Sharon Maehl suggests having the baby in the hospital, but staying there for as short a time as possible. She takes you through all the decision points and wraps up with the account of the birth of her second child.

The key to this way of giving birth, along with finding the right doctor and hospital, is making your mind up ahead of time that you won't stay, according to Maehl. She says,

Somewhere along the line you should tell the staff that you'll have to be running along soon (you left a cake in the oven?) Whatever you do, though, don't mention this to anyone in the hospital until the baby is born. If you tell the doctor during your pregnancy, he may even refuse to accept you for pre-natal care. Doctors are not known for their flexibility. Best wait until the baby is born and safely in your arms before you tell anyone your plans.

Her idea minimizes the time in hospital and the pressure from doctors and nurses for medical interventions, while making sure that if anything does go wrong, help is right there.

Oxytocin Withdrawal

In The Truth about Mamahood, Claire writes about depression after she stopped breastfeeding.

The first few days, I felt super sad ending the long era of our nursing relationship. I missed seeing her little face nursing, my little baby happily suckling. Then I started to feel extremely light-headed and got some headaches, which was weird- but then depression hit me like a ton of bricks. I was in my dance class (my first without Uma in a long time) and just started bawling over the loss of my mother.

It does seem that, as she implied in her title, that the intensity of these feelings may be due to the sudden lowering of her oxytocin after weaning. I wonder if it's possible to taper off breastfeeding, so your body wouldn't go through such an abrupt withdrawal?

Validation for "Tend and Befriend"

In 2000, Shelly Taylor, a social psychologist at UCLA proposed an alternative model to the well-known fight-or-flight response.

Based on an analysis of a wide range of research by others, Taylor hypothesized that women faced with threat might have evolved a different response, something she called "tend and befriend." The idea is that females in ancient times had to protect the children while the men fought off the danger. So, they gathered together in groups to defend the youngsters.

This tendency would likely be influenced by oxytocin, the neurochemical that, among other things, drives us to connect with others. Sue Carter of the University of Illinois,  has done work with prairie voles showing that when they're isolated and stressed, their oxytocin levels rise. She thinks this causes them to seek out others -- in human terms, you could say, for support.

Many have pooh-poohed Taylor's ideas, possibly because she's a psychologist, not a neuroscientist, possibly because she's a woman.

But now, researchers at the University of Pennsylvania have done a brain imaging study that supports her hypothesis.

In the study led by J.J. Wang, men  and women were stressed by being asked to do arithmetic in front of a panel of strangers who constantly asked them to go faster or start over if they made a mistake. According to Science Daily:

The researchers measured heart rate, cortisol levels (a stress hormone), subjects' perceived stress levels throughout the experiments, and regional cerebral blood flow (CBF), which provides a marker of regional brain function. In men, it was found that stress was associated with increased CBF in the right prefrontal cortex and CBF reduction in the left orbitofrontal cortex. In women, the limbic system -- a part of the brain primarily involved in emotion -- was activated when they were under stress.

In other words, under stress, the men got busy thinking harder, while the women  increased their emotional activity. The hypothalamus, producer of oxytocin, is part of the limbic system. It's possible that these women's brains secreted extra oxytocin, which may have calmed them.

Taylor, S.E., Klein, L.C., Lewis, B.P., Gruenewald, T.L., Gurung, R.A.R., & Updegraff, J.A. (2000).  Biobehavioral responses to stress in females: Tend-and-befriend, not fight-or-flight.  Psychological Review,107, 411-429.

Neglected Kids More Likely to Be Obese

A study at Temple University found that kids who are neglected are more likely to be obese. Abuse or maltreatment, on the other hand, didn't seem to affect their weight.

Temple's Robert Whitaker looked at data from the Fragile Families and Child Wellbeing Study of nearly 5,000 children. At age three, children'sheight and weight were measured, while mothers answered a questionnaire about three types of child maltreatment in the prior year: neglect (such as not providing proper supervision for the child), corporal punishment (such as spanking the child on the bottom with a bare hand) and psychological aggression (such as threatening to spank the child but not actually doing it).

According to the article,

Eighteen percent of the children were obese, and the prevalence of any episode of neglect, corporal punishment or psychological aggression was 11 percent, 84 percent and 93 percent, respectively.

The odds of obesity were 50 percent greater in children who had experienced neglect, after controlling for the income and number of children in the household, the mothers' race/ethnicity, education, marital status, body mass index, prenatal smoking and age, and the children's sex and birth weight.

On the other hand, there was no correlation between corporal punishment or psychological aggression and overweight.

This makes sense if you look at overeating as a way to compensate for oxytocin deprivation. We tend to see overeating as a reaction to stress, which it is. But the stress of isolation is the lack of the ability to connect in an oxytocin-producing interaction with another person. (Although in prairie voles, isolated animals actually produce more oxytocin;  researchers at University of Illinois who did these experiments think this oxytocin production drives the animal to try harder to connect.  See The Amazing Vagus Nerve and The Sex/Food/Love Connection.

Eating -- or rather digesting food, especially fatty food -- sends signals from the gut to the brain via the vagus nerve. Those signals cause the hypothalamus to release oxytocin, which travels to the gut and creates the sensation of satiety.

It seems very likely that this oxytocin release also tweaks the neurons in the brain that create the pleasure in social interactions. So, it makes perfect sense that kids who are lonely for their mothers -- or for anyone to pay attention to them -- could use eating to take the place of social relationship.

Higher Oxytocin Predicts a Better Mother/Child Bond

A just-published study is the very first to connect oyxtocin in humans to the bond between mother and child.

Numerous animal studies -- in mice, rats and prairie voles -- have shown a strong connection between oxytocin and maternal behavior, while Kerstin Uvnas-Moberg did a series of studies of human mothers showing a relationship between breastfeeding and a mother's feelings of calm and connectedness. But cautious scientists have been reluctant to say what feels so true -- that oxytocin bonds humans in all the ways it does animals.

This study from Bar-Ilan University led by Ruth Feldman found a strong correlation between oxytocin levels and mothers' feelings toward their babies during pregnancy and after birth. From the APS story posted on Scientific Blogging:

Initial levels of oxytocin at the first trimester predicted bonding behavior. Therefore, mothers with a high level of the hormone at the beginning of the pregnancy engaged in more of the aforementioned bonding behaviors after birth.

Additionally, mothers who had higher levels of oxytocin across the pregnancy and the postpartum month also reported more behaviors that support the formation of an exclusive relationship (i.e. singing a special song to the infant, or bathing and feeding them in a special way). These mothers were also more preoccupied by thoughts of checking on the infant, the infant’s safety when they are not around, and the infant’s future.

I reported on this study in my book, ahead of its publication the journal, and corresponded with one of th researchers, Ari Levine. He told me something a bit different -- that it wasn't a mother's oxytocin level, but how much her oxytocin level increased that predicted bonding.

In fact, that's what the study showed:

The increase in OT from early to late pregnancy correlated with higher maternal-fetal bonding.