Why Do We Hold Hands?

Most of us don't examine our urge to hold hands with our loved ones too closely. It feels nice; their hands fit nicely with ours; and we can walk along in the same direction while also being bodily connected — what else do we need to know? But the impulse has actually attracted quite a lot of scientific interest; researchers want to know where the practice came from, whether it offers any psychological and physical benefits, and why we hold hands specifically, rather than any other part of the body. Why aren't we all walking around touching elbows or hips, for example? And why do we hold hands to express a close bond with someone we already care about, rather than using the move to try to form new bonds with strangers?

Though we may not think of it this way, it turns out that hand-holding is a psychological and social action as much as it is a physical one. There are wide cultural differences in the implications of hand-holding between friends and romantic partners in different cultures throughout the world; anthropologists often note that, for example, hand-holding between young women isn't interpreted as romantic in places like South Korea. And, more worryingly, a lot of ideas about power and dominance in relationships are on display in hand-holding behavior as well; a 2013 study of South Carolina people holding hands on the beach found that men were far more likely to be "dominant" (have their hand on top) over women in hand-holding, whether they were taller or not, and that women were more likely to be dominant over children when holding hands. Turns out, grabbing a hand to squeeze is rarely a simple thing.

So why do we hold hands in particular situations, what does it do to us, and what does it imply about the general spectrum of human touch and communication? Let's have a look at the scientific and psychological landscape surrounding this very ordinary act.

1. It Raises Resistance To Pain And Reduces Stress

Two of the most quoted studies about hand-holding are focused on studying what happens when pain is inflicted on people in relationships (a.k.a. a study which would have appealed to me greatly back when I was single for a while). The first, conducted in 2006, looked at stress reduction, while the second, conducted in 2009, looked at pain and how we experience it. Taken together, they create an interesting picture regarding the value of hand-holding on a practical, physiological level.

The 2006 study was conducted by researchers at the University of Virginia, and used 16 happily married heterosexual couples in their thirties as test subjects. The researchers hooked up the wives to machines delivering electric shocks to their ankles, then measured the activity in the threat-reaction parts of their brains. When they were warned about a future shock, that part of the brain leapt to life; but when they were holding hands with their partner, the brain activity was significantly less. This didn't work when holding hands with just anyone; it was all about the familiarity of the person at the other end of the clinch.

The second study, conducted in 2009, was a little bit different. Again, it was focussed entirely on the reactions of women; in this case, the subject were 25 young women in long-term happy relationships with male partners. They were given mild burns by a research team at the University of California under various circumstances, and then asked to rate their level of discomfort. If they were looking at a photograph of their partners or holding hands with them, the presence of their partner seemed to create an "anesthetic" effect: the physical stimulus wasn't any less painful for them, but the women themselves experienced it as less intense.

Before we try to apply these studies to our lives, we need to note a few things about them; the most important fact to remember is that they only looked at women in straight relationships. The responses of male brains and people in same-sex relationships may not be different, but they haven't yet been accounted for. And they don't explain the point of why we hold hands; they just highlight numerous potential advantages to the practice. It does, however, explain why we go to hand-holding in particular circumstances, like in scary or stressful situations that may involve physical or emotional pain. It's likely something to do with our positive response to touch and pressure in times of stress, and to the fact that levels of oxytocin, the "cuddle chemical," go up when people hold hands.

2. It Corresponds With A Particular Pressure Point

The Wall Street Journal highlighted something particularly interesting that's been discovered about the hands: a particular pressure point, in the part of the hand between the thumb and forefinger, may help with very severe pain, though we're not entirely sure why.

The 2011 study that the WSJ reported on something called the hegu point, one of the most critical parts of acupuncture practice. (Acupuncture, an ancient Chinese traditional medicine technique, involves inserting needles at various pressure points across the body to relieve symptoms of various ailments.) The researchers conducting the hegu point study at the University of Maryland and Johns Hopkins University School Of Medicine weren't looking at romantic hand-holding; they were trying to find out whether the hegu point could be useful in relieving severe pain for particular cancer patients.

The cancer patients they used were undergoing a very painful procedure called "bone marrow aspiration," and during the process they were either given acupuncture at the hegu point or at some other part of the hand with no apparent benefit. Those who were experiencing only average pain levels during the procedure who were treated with the hegu point didn't see any benefit, but there was a decrease in pain among the people who were really suffering. This may shed some light on the specific mechanisms of comfort in hand-holding, but we're still in the dark about the specific working of the hegu point as yet.

3. Hands Are Acutely Sensitive To Touch

One of the reasons we seem to hold hands by default rather than, say, linking arms or holding each other's hair, is that hands themselves are deeply sensitive areas. We'll explore the particular responses to touch in human physiology and psychology shortly, but it's important to understand that if we want to touch each other in a way that really fires the nerve endings, the hands are an excellent place to start.

Professor Eric Rabquer, a professor of biology at Albion College, expressed the idea to the Albion Pleiad that the high number of nerve endings in the hand (so many that they can detect two needles touched barely millimeters apart as two separate points) gives it primary status as a mechanism for touch, and that our reliance on hands throughout our evolution may be connected to the importance we give to palm-to-palm, finger-to-finger contact. Essentially, he proposes that we've developed a huge number of nerve endings in our hands to help us navigate threats, use tools and do complicated tasks, and that this fact has led us to look to them as emotional tools as well. It's a thesis that will likely never be proven, but it's interesting to think that our hand-holding may be embedded in our very distant evolutionary past.

4. Touch Has Its Own Language

We now known that touch of any kind, from nose-to-nose to a passing graze on the bare arm, is hugely beneficial for humans, and that living without touch of any sort is deeply harmful. Psychology Today's extensive investigation of the importance of touch to human psychology and health touches (pun intended) on many fascinating aspects, like the famous University of California Berkeley study that found the NBA teams with the highest level of physical contact on-court got the highest scores. But when it comes to hand-holding, one thing jumps out as crucial: the fact that touch is an excellent communicative mechanism.

It turns out that touch and hand-holding can send huge amounts of emotional information between partners, whether they're aware of it or not. Touch as communication had its first major scientific boost, according to Psychology Today, in 2009, when Professor Matt Hertenstein asked blindfolded volunteers to try and communicate various emotions to strangers through touch alone — and found, to his astonishment, that they "got the message" 75 percent of the time. Hand-holding, it seems, is part of a vast spectrum of communication mechanisms through touch, whether it's with a partner, family members or strangers.

5. We Learn It At A Very Young Age

When did we first start holding hands? The Huffington Post points out that it often occurs as soon as we're born; the palmar grasp reflex, as it's known, is the adorable propensity of very small babies (sometimes in the womb) to react to the touch of fingers by squeezing them tightly, and primates of all kinds show the same tendency.

The idea that one of our first interactions with other humans may shape our future actions and assessments of affection isn't proven, but it's a valid psychological thesis: the people who hold our hands in early life are all caregivers, parents, grandparents, people guiding us across the road, or schoolmates when we're walking down the road in pairs. Linking hand-holding with care and safety isn't a difficult psychological jump; it's an easy way to show affection and to communicate security to another person, just as it was communicated to us as children.

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