Where we like being touched, where we don't and why by Ben Tinker

Where we like being touched, where we don't and why

By Ben Tinker, CNN

Updated 11:28 AM ET, Fri October 30, 2015

The blue-outlined black areas highlight taboo zones, where a person with that relationship is not allowed to touch. Blue and red labels signify male and female subjects, respectively.

Story highlights

• Researchers determined where, and by whom, people are most comfortable being touched
• Still, an expert said, "One's response to touching is totally context-dependent"

(CNN)After a series of experiments to determine where, and by whom, people are most comfortable being touched, researchers made some surprising, and some intuitively obvious, findings, recently published in the medical journal PNAS.

Perhaps not so surprising, women are more at ease with being touched than men. And men are more comfortable being touched by a woman than by another man.

But then, men feel more comfortable being touched by strangers than by women. And women were allowed to touch more areas of the body than men.

Researchers at Aalto University in Finland and the University of Oxford in the United Kingdom showed 1,368 participants front and back silhouettes of human bodies, with words designating members of their social network, such as family, friends, acquaintances and strangers. They were asked to color in the bodily regions where each individual in their social network would be allowed to touch them.

Hot spots

"The partner was allowed to touch basically anywhere over the body, closest acquaintances and relatives over the head and upper torso, whereas strangers were restricted to touch only the hands," the authors wrote.

"Taboo zones, where touching was not allowed, included the genitals for extended family and males in family, acquaintances and strangers, as well as the buttocks for males in extended family, acquaintances and strangers."

Interestingly, frequency of social contact with an individual did not predict the areas designated for preferred or acceptable touching. The greater the emotional bond, however, the larger the bodily area open for touching.

But it's more complicated than that, some experts say.

"One's response to touching is totally context-dependent," said David J. Linden, a neurobiologist and author of "Touch: The Science of Hand, Heart and Mind." "If you do it in a laboratory or you ask people to imagine, it's really hard to get a useful answer."

"Imagine a caress on your arm from your sweetheart when you're feeling connected and loving. Now imagine the exact same caress, yet it feels completely different if ... it's in the middle of an argument that's unresolved. It will feel different from the very first moments of perception, because areas of the brain responsible for touching also compute things like context: 'Am I under threat?' 'What's my emotional state?' 'How much attention am I paying to this?' "

That is to say, if researchers were to ask the same participants in the study to take the test again -- while in a different frame of mind -- the results would be totally different.

Another important caveat to note is the limit on the data set. Participants were selected from five European countries: Finland, France, Italy, Russia and the United Kingdom.

"They confined their analysis to countries and cultures where a certain degree of social touching is allowed," said Linden. "If you did the study with Orthodox Jews or devout Muslims or other groups out in the world, it wouldn't work at all."

Pursuit of pleasure

"Acceptability of social touch was most limited (i.e., most relationship-specific) in regions with the strongest hedonic sensitivity," the authors wrote. In other words, our most sensitive spots are, well, our most sensitive spots.

"Different parts of the skin convey different kinds of touch," said Linden. "In the brain, there is a different biological basis for these maps. In general, we're averse to being touched sexually by strangers -- and women are more averse than men. Your (sexual organs) feel vulnerable and you want to protect them."

Linden said there are different kinds of nerve endings that convey different kinds of information -- but we don't yet know the whole story.

"We know that a touch on the genitals feels different than a touch just about anywhere else on the body," said Linden. "If we took the skin of the genitals and looked at it under a microscope, we would see something different that accounts for that: mucocutaneous end organs, that look like coiled, naked nerve endings."

This may be one reason we're more comfortable being touched on our backs as opposed to, say, on our lips.

If you were to be poked with two pencil points on the small of your back, you likely wouldn't be able to tell if it was in fact one point or two. If you were poked with two pencil points on your lip, though, you'd know for sure and feel it much more distinctly.

Stranger danger

Men and women also have different relationships with sexual violence.

"From an evolutionary standpoint, it makes sense that women are wary of being touched by strangers," said Wendy Walsh, a relationship expert, author and radio host. "Women have evolved mechanisms to be choosy about whom they mate with and to fear rape by a stranger. However, touch by friends is both relational -- women tend to befriend as a buffer against stress -- and pleasurable. Touch gives a nice boost of dopamine, the 'feel-good' hormone."

"Men, on the other hand, tend to be less choosy with whom they mate," Walsh said. "So it stands to reason that touch by a stranger increases the chances for a sexual opportunity."

Mutated Thoughts and Other Wee Beasties in My Brain

Can you die from lack of touch? This is not the strange question it may at first appear to be. If you are a newborn, the answer is certainly yes. A syndrome called "failure to thrive" has been documented, mostly among kids in orphanages where there are few staff to care for many babies. A child who isn't cuddled and emotionally warmed stops eating and can die. No, really. This has been known for a long time, and has given rise to the routines in neonatal intensive care units in which babies are held periodically, on schedule. Touch makes it more likely that the babies will eat and respire and heal well. Most of these babies are premature; they would still be in the womb if born full term. Yet they respond to human touch all the same as if born at nine months. Fascinating. How important touch must be!

But can adults suffer this same fate? I'll bet yes. We know that existing pathologies can be made worse, like depression. I would even bet that depression can be triggered by lack of touch, at least in those predisposed to it. Irritability, fear, loneliness, depression;  I know that folks can get mighty cranky when they get lonely, and aloneness can give rise to things like psychosis, believe it or not. It has been determined that isolation is perhaps the severest form of torture, and severe symptoms can arise in less than hours. Ask any jailer about the newly incarcerated.

And you can be in a room full of people and feel quite lonely, you know, so it's not just locking someone up in a cell that causes separation and desperation. We all need fair amounts of interaction, both physical and emotional, in order to do well psychologically, to stay on track. And although I'm not talking about sex, any physical touch can be soothing; we just hope the touch is wanted and appropriate. I have recommended to my depressed patients who experience no physical touch to get a massage at least weekly. That has been a great suggestion, according to them.

I need a new goal. I need to focus on something tangible that I can later point to and say, "I did that."

I am feeling my age. My knees hurt, two of my fingers simply don't work any longer, I am having trouble balancing when I stand, I no longer have any sensation below my ankles, and I am getting tired. So? If someone had told me that getting older sucks, would I have enjoyed myself more when I was still fully functional?

When should a parent put their daughter on birth control, specifically the pill? This is a complicated issue. If she is sexually active, the answer is almost always yes. But what if she's not? Can you know when she will be? Would she come to you and say, "I think I am almost ready to start having sex. I think I wish to explore my birth control options." Yeah, sure.

But if you start her too early, there can be risks to her health. Too late, and she may become pregnant.

I vote for early and unabashed communication about everything, including sex. I think kids make better decisions when they have good information. The problem is that most parents are too fearful or embarrassed, or are simply not equipped with enough information to do an adequate job. I am a huge supporter of comprehensive sex education in K-12. That's right, K-12.

When comprehensive sex education is employed, most of what you discuss isn't about sex. That may come as a shock to many of you, but it's true. And such programs also offer abstinence as a viable, useful option. It's also true that such programs use age-appropriate language and don't offer the nitty-gritty all at once. That's a myth. Now, there aren't many excellent teachers in this area, and that's a real shame. I have been a sex educator since the 80's (although I'm not saying I'm a great one), so I have some street cred here. And lastly, talking about sex and offering birth control doesn't make kids want to run out and have sex; no more than talking with someone who's depressed about whether they have considered suicide will make them kill themselves. The kids are already thinking about sex. They just don't have the facts, although they have tons of mythologies. I heard from one not long ago: a 15 year old who is pregnant, said, "I though if you stood up after you had sex you couldn't get pregnant." That's her parent's fault.

I wish it were true that parents provided such material and discussions, but that's not what's happening. There is a positive correlation between teen pregnancy, STI rates and kids not getting comprehensive education and services. In other words, the states that are far right religiously that preach abstinence only typically have the highest rates of STIs and teen pregnancies. Our state is number one. I think that's irresponsible.

If you look at foreign analogs to this the data are clear: teach kids what they need to know about building relationships, how sex is and is not connected to real relationships, how to protect yourself, how to make good decisions, how to know when you're really in love, how to know when people lie and why they do that, provide access to full health care including sexual care to everyone (don't get me started) and so on, and you get kids waiting longer to have sex, lower pregnancy rates, and fewer sexually transmitted infections. I'll take the Scandinavians over us any day.