“What is it about the bond between human and dog that is not like the relationship between parent and child?
Now science offers a new explanation for the similarity. When our dogs gaze into our eyes with that “you are everything to me” look, our bodies — and theirs as well — are flooded with oxytocin, the hormone of love and nurture that cements the bond between people.”
Strangers can “see” a persons trustworthy genes through their behaviors, suggests a new study finding that a single genetic change makes a person seem more compassionate and kind to others.
The gene in question is the “love hormone,” or oxytocin, receptor. A single change in the receptor can result in higher or lower empathy, or how much you can emotionally relate to others. These changes can be detected by strangers from just 20 seconds of soundless video; these strangers could literally see the person’s genes manifesting in their behavior.
Our genes are made of bases, called nucleotides, which come in four types: A, T, C, and G. Researchers have found that switching out a single A to a G on the “love hormone” receptor can have profound effects on behavior. A person with two copies of this A-to-G mutation (one from each parent) report having more empathy.
Research could lead to advanced treatments for social anxiety, post-traumatic stress disorder and other brain behavioral issues.
The research is in Nature. (full access paywall)
Research: “Oxytocin enables maternal behaviour by balancing cortical inhibition” by Bianca J. Marlin, Mariela Mitre, James A. D’amour, Moses V. Chao and Robert C. Froemke in Nature doi:10.1038/nature14402
Image: Researchers report oxytocin boosts social information processing. The image is for illustrative purposes only. Image credit: NeuroscienceNews.
It’s a question that bedevils dog owners the world over: “Is she staring at me because she loves me? Or because she wants another biscuit?”
Research published Thursday in the journal Science suggests that love (or something close) could be behind that stare. The work shows that when dogs and their people gaze into each other’s eyes, all get a boost in their circulating levels of oxytocin — a hormone thought to play a role in trust and emotional bonding.
A quarter of U.S. couples sleep apart. Are they missing important health benefits?
Stolen sheets, snoring and hot flashes are just some of the annoyances that lead a quarter of U.S. couples to sleep apart, according to the National Sleep Foundation. But do the benefits of sharing a bed outweigh such costs? One neurologist, Rachel E. Salas, the assistant medical director for the Johns Hopkins Center for Sleep, shares her expert opinion.
People have slept in the same bed as a family unit for millennia—mainly for warmth and protection from predators and outsiders, says Dr. Salas, who has studied the history of sleep.
“Back in the cave days and even through recent history, many people didn’t bathe often or have lots of clothes, so they slept naked. Sleeping together was essential for warmth,” she says.
Then as now, she says, it is human to feel safer knowing someone is lying close beside you.
The Science of Spooning
There have been few scientific studies on couples sleeping together. But experts say oxytocin, the so-called love hormone, is released during many types of touching, including cuddling. Increased oxytocin helps the body relax, reduces blood pressure and promotes healing, Dr. Salas says. It also results in emotional feelings related to affection, security and love.
A recent study showed a link between quality of sleep and couples’ daytime interactions. For men, the better the sleep a couple got, the smoother their next-day spousal interactions, Dr. Salas says. For women, less negative interaction with their husbands during the day led to more restful sleep that night.
“I can’t quote any studies, but from my neurology background, I would suspect that having a person that you are the protector for or who protects you nearby increases the release of neurotransmitters involved with good sleep,” Dr. Salas says.
Getting quality sleep enhances a person’s quality of life, Dr. Salas says. People with sleep disorders, such as apnea, night terrors or sleepwalking, may benefit from having a bed partner who can observe nighttime behaviors and help with a diagnosis.
But for some people, sleeping together could do more harm than good: “If you wake up often from ambient noises or get hot in your sleep, keeping your bed to yourself may be exactly what you need.”
‘Humans are Social Creatures’
Sleeping apart is a relatively modern phenomenon and varies across cultures, Dr. Salas says. “My father is from Mexico and my mom is from Texas, and both of them slept with all of their brothers and sisters when they were growing up,” she says. If you go to other countries, whole families still sleep together, she says. Humans are social creatures. We want someone nearby.
The love hormone, the monogamy hormone, the cuddle hormone, the trust-me drug: oxytocin has many nicknames. That’s because this naturally occurring human hormone has recently been shown to help people with autism and schizophrenia overcome social deficits.
As a result, certain psychologists prescribe oxytocin off-label, to treat mild social unease in patients who don’t suffer from a diagnosed disorder. But that’s not such a good idea, according to researchers at Concordia’s Centre for Research in Human Development. Their recent study — published in Emotion, a journal of the American Psychological Association — shows that in healthy young adults, too much oxytocin can actually result in oversensitivity to the emotions of others.
With the help of psychology professor Mark Ellenbogen, PhD candidates Christopher Cardoso and Anne-Marie Linnen recruited 82 healthy young adults who showed no signs of schizophrenia, autism or related disorders. Half of the participants were given measured doses of oxytocin, while the rest were offered a placebo.
The participants then completed an emotion identification accuracy test in which they compared different facial expressions showing various emotional states. As expected, the test subjects who had taken oxytocin saw greater emotional intensity in the faces they were rating.
“For some, typical situations like dinner parties or job interviews can be a source of major social anxiety,” says Cardoso, the study’s lead author. “Many psychologists initially thought that oxytocin could be an easy fix in overcoming these worries. Our study proves that the hormone ramps up innate social reasoning skills, resulting in an emotional oversensitivity that can be detrimental in those who don’t have any serious social deficiencies.”
As Cardoso explains, “If your potential boss grimaces because she’s uncomfortable in her chair and you think she’s reacting negatively to what you’re saying, or if the guy you’re talking to at a party smiles to be friendly and you think he’s coming on to you, it can lead you to overreact — and that can be a real problem. That’s why we’re cautioning against giving oxytocin to people who don’t really need it.”
Ultimately, however, oxytocin does have the potential to help people with diagnosed disorders like autism to overcome social deficits.
But, says Cardoso, “The potential social benefits of oxytocin in most people may be countered by unintended negative consequences, like being too sensitive to emotional cues in everyday life.”
Researchers at the University of Adelaide say addictive behaviour such as drug and alcohol abuse could be associated with poor development of the so-called “love hormone” system in our bodies during early childhood.
The groundbreaking idea has resulted from a review of worldwide research into oxytocin, known as the “love hormone” or “bonding drug” because of its important role in enhancing social interactions, maternal behaviour and partnership.
This month’s special edition of the international journal Pharmacology, Biochemistry and Behavior deals with the current state of research linking oxytocin and addiction, and has been guest edited by Dr Femke Buisman-Pijlman from the University of Adelaide’s School of Medical Sciences.
Dr Buisman-Pijlman, who has a background in both addiction studies and family studies, says some people’s lack of resilience to addictive behaviours may be linked to poor development of their oxytocin systems.
“We know that newborn babies already have levels of oxytocin in their bodies, and this helps to create the all-important bond between a mother and her child. But our oxytocin systems aren’t fully developed when we’re born - they don’t finish developing until the age of three, which means our systems are potentially subject to a range of influences both external and internal,” Dr Buisman-Pijlman says.
She says the oxytocin system develops mainly based on experiences.
“The main factors that affect our oxytocin systems are genetics, gender and environment. You can’t change the genes you’re born with, but environmental factors play a substantial role in the development of the oxytocin system until our systems are fully developed,” Dr Buisman-Pijlman says.
“Previous research has shown that there is a high degree of variability in people’s oxytocin levels. We’re interested in how and why people have such differences in oxytocin, and what we can do about it to have a beneficial impact on people’s health and wellbeing,” she says.
She says studies show that some risk factors for drug addiction already exist at four years of age. “And because the hardware of the oxytocin system finishes developing in our bodies at around age three, this could be a critical window to study. Oxytocin can reduce the pleasure of drugs and feeling of stress, but only if the system develops well.”
Her theory is that adversity in early life is key to the impaired development of the oxytocin system. “This adversity could take the form of a difficult birth, disturbed bonding or abuse, deprivation, or severe infection, to name just a few factors,” Dr Buisman-Pijlman says.
“Understanding what occurs with the oxytocin system during the first few years of life could help us to unravel this aspect of addictive behaviour and use that knowledge for treatment and prevention.”