The skin and hand evolved to enable adaptive response to heat and for tool use. Alongside these pragmatic gains, our hominid predecessors evolved a communicative system that became central to how humans form and maintain bonds. Most obviously, the skin is the platform for intimacy and sexual relations. It is a medium in which individuals in conflict channel aggression, through pinches, pokes, prods, and punches. We soothe and reassure with hands on skin. The skin and touch are a central medium in which the goodness of one individual can spread to another, resulting in high jen ratios as the primary orientation in groups.
CONTACT HIGH
Faith healers have been in human society since at least the time of the classical Greeks and Romans. Central to their repertoire of healing skills is touch. Recent neuroscience suggests that, at least in the use of touch, faith healers may have been on to something. Scientists have learned that touch is a basic reward, as potent as the sweetest of summer peaches or the scent of blooming jasmine. The progenitor of this view is Edmund Rolls, of Cambridge University, who has studied the orbitofrontal cortex (OFC), which, as we will recall, was damaged in Eadward Muybridge during his fateful stagecoach accident in east Texas. Rolls’s thesis is that this region of the brain processes information about basic rewards, which help individuals navigate their physical and social environments, acting in ways, presumably, that bring about more rewarding social encounters, more nutrition-rich searches for foods, and so on. He has found that sweet tastes and pleasing smells stimulate activity in the OFC, in particular in hungry animals. But there is more. He has also documented that the simple touch of the arm with a soft velvety cloth activates the OFC, so important to our understanding of how to obtain rewards. This is a remarkable finding: Touch (the right kind, of course) is as powerful and immediate a reward as chocolate or the scent of Mother to an infant. Touch is a primary color in the color scheme of pleasure, wired deep into our nervous systems.
Further scientific studies found that touch—again, the right kind—sets in motion a cascade of rewarding biochemical reactions. For example, in one study participants received a fifteen-minute Swedish massage, the type that is stock in trade at spas and now a much-appreciated service at more forward-looking airports. While participants’ Merkel cells were being pleasingly pressed, their blood was drawn. A quick neck rub to the shoulders by a stranger triggered the release of oxytocin, a neuropeptide that promotes oceanic feelings of devotion and trust. Other studies have found that massage (like Prozac) increases levels of the neurotransmitter serotonin, and that it reduces levels of the stress hormone cortisol. Touch also appears to release endorphins in the recipient—a natural source of pleasure and pain relief.
Touch, then, triggers activation of the orbitofrontal cortex and the release of oxytocin and endorphins—biological platforms of social connection. Just as importantly, recent studies of maternal behavior in rats suggest that the act of touching is physiologically rewarding for the toucher. Rat mothers devote a great deal of time to licking their rat pups and coming into nose-to-nose physical contact with their offspring. Recent studies have found that rat mothers who lick their pups a lot, who touch their offspring a great deal, get surges of dopamine upon physical contact. Dopamine is a neurotransmitter that is involved in the pursuit of rewards; it underlies our experience of sensory pleasure. When we touch, the implication is, we get a burst of pleasure as well.
Thankfully, the benefits of touching are not limited to rat pups. Scientists have found, for example, that depressed mothers who are encouraged to touch their infants regularly and to massage them experience reduced symptoms of depression and begin to play more with their children. Elderly individuals who volunteer to give massages to infants report reductions in anxiety and depression and enhanced well-being.
Humans, then, are blessed with an inexhaustible resource of rewards—touch. Through millisecond touches in our daily living, we can provide pleasure, reward, and encouragement to others. Experimental studies have found that when teachers are randomly assigned to touch some of their students and not others with friendly pats on the back, those students who receive the rewarding touch are nearly twice as likely to volunteer comments in class. When medical doctors are experimentally assigned to touch some patients but not others, those patients who are touched in a warm fashion estimate the visit with their doctor to be two times longer than those patients who go untouched. Students touched by librarians while checking out books indicated a much more favorable attitude toward that bastion of good undergraduate fun—the library—than students who were not casually touched by the librarian. Touch is the original contact high.
TOUCH TO THRIVE
In her excellent book Touch, Tiffany Field, the world’s leading investigator of touch, recounts a moving story about an incident in a nursing home for the elderly. Two elderly residents, a man and a woman, were found missing during the dinner hour. They were soon discovered in a small utility closet, embracing one another like old friends. The staff quickly deemed them “sex offenders” and prevented them from further contact. Isolated, they withdrew from friends and families. Within weeks they were dead.
It is not a stretch beyond rigorous empirical evidence to claim that touch is essential to our physical and mental vitality. Some of the earliest systematic observations on this theme came from studies of orphanages, where only seventy-five years ago mortality rates for infants hovered between 50 and 75 percent. In one, run by a warm, friendly, affectionate German woman, the infants thrived. In another, where the children received no touch, the orphans were undernourished, sickly, and more likely to die. In a more systematic comparison, Renée Spitz assessed how well infants were doing at two orphanages, one in which female convicts served as mother surrogates, the other a foundling home. In both the infants were given food and clothing and kept clean. The foundlings had better access to medical services and were kept in a cleaner environment, but they were deprived of touch. They fared worse in terms of life expectancy and cognitive development.
More controlled studies have yielded comparably striking results showing how critical touch is to thriving. Tiffany Field has found that massages given to premature babies lead, on average, to a 47 percent increase in weight gain. In another study, thirty human infants were observed in the course of a painful heel lance procedure, in which the infants’ heels were cut by medical doctors. Some of the infants were held by their mothers in whole-body, skin-to-skin contact. Others underwent the procedure while swaddled in a crib. The infants who were touched during the procedure cried 82 percent less than the comparison infants, they grimaced 65 percent less, and they had lower heart rate during the procedure.
Touch alters not only our stress-related physiology but the development of the underlying physiological systems that render the human stress response more labile and strong. Responses to stress are governed by two populations of neurons in the central nervous system. One population in the paraventricular nucleus of the hypothalamus projects to the anterior pituitary, which produces the adrenocorticotropin hormone (ACTH) that causes the release from the adrenal gland of the stress hormone glucocorticoid. The second population of neurons resides in the amygdala and projects to a region known as the locus ceruleus, which, when stimulated, leads to the release of noradrenaline. These respective neural populations ultimately stimulate the liver, the heart and circulatory system, and different organs. These organs then kick into action (for example, the liver increases glucose output to maintain stable blood sugar levels) to support stress-related behavior.