Skin hunger helps explain your desperate longing for human touch

Alice*, a 31-year-old director from London, has been breaking the coronavirus lockdown rules. "I almost don't want to tell you this," she says, lowering her voice. Her violation? Once a week, Alice, who lives alone, walks to the end of her garden to meet her best friend Lucy*. There, with the furtiveness of a street drug deal, Lucy hugs her tightly. Alice struggles to let her go. "You just get that rush of feeling better," Alice says. "Like it's all okay."

Aside from Lucy's hugs, Alice hasn't been touched by another person since March 15, which is when she went into a self-imposed lockdown, a week before the official government advice to self-isolate. "I've found it really hard," she says. "I am a huggy person. You start to notice it after a while. I miss it." She feels guilty about her surreptitious hugs. "I feel like I can't tell my other friends about it," Alice says. "There's a lot of shaming going on. I know we aren't meant to. But I am so grateful to her [Lucy] for checking in on me. It gives me such a lift."

Alice is experiencing the neurological phenomenon of 'skin hunger', supercharged by the coronavirus pandemic. Skin hunger is the biological need for human touch. It's why babies in neonatal intensive care units are placed on their parent's naked chests. It's the reason that prisoners in solitary confinement often report craving human contact as ferociously as they desire their liberty.

"When you touch the skin," explains Tiffany Field of the Touch Research Institute at the University of Miami, "it stimulates pressure sensors under the skin that send messages to the vagus [a nerve in the brain.] As vagal activity increases, the nervous system slows down, heart rate and blood pressure decrease, and your brain waves show relaxation. Levels of stress hormones such as cortisol are also decreased." Touch also releases oxytocin, the hormone released during sex and childbirth to bond us together. In other words, human touch is biologically good for you. Being touched makes humans feel calmer, happier, and more sane.

Without touch, humans deteriorate physically and emotionally. "We know from the literature that lack of touch produces very negative consequences for our wellbeing," says Alberto Gallace, a neuroscientist at the University of Milano-Bicocca. He explains that humans are inherently social creatures; studies have shown that depriving monkeys of physical contact leads to adverse health outcomes. Our brains and nervous systems are designed to make touch a pleasant experience, he says. "Nature designed this sensory modality to increase our feelings of wellbeing in social environments. It's only present in social animals that need to be together to optimise their chances of survival."

Before the coronavirus pandemic, many developed nations were already at risk of becoming touch-free zones, with no-touch policies now common in schools and public institutions, for safeguarding and litigation reasons. Field's Touch Research Institute has been working on a global airport study to observe how much people touch each other whilst waiting to board flights. (The research is currently on pause.) "We observed over 4,000 interactions," Field says. "The data showed that, at least in public, there is virtually no touching - 98 per cent of the time, people are on cell phones."

With social distancing protocols in place in countries across the world, those who live alone find themselves enduring months without human touch. This is a particularly cruel irony, given that skin hunger actually weakens our immune systems - making us potentially more susceptible to coronavirus. "I'm very concerned," says Field, "because this is actually the time we need human touch the most." She explains that touch is instrumental in immune function, because it reduces our cortisol levels. When cortisol levels are high, our immune system is depleted: cortisol kills natural killer cells, a type of white blood cell that attacks viruses for us. Field tells me that human touch has been shown to increase natural killer cells in patients with HIV and cancer.

Gallace is profoundly concerned about the mental health implications of prolonged skin hunger for those locked down alone, particularly given that a global pandemic is in itself a stressful and anxiety-provoking situation. "We use touch for comfort," he says. "When we are in danger or anxiety, being touched is a form of help. A lack of touch increases the stressfulness of situations." He explains that studies have shown that people perform tasks better when they are clapped on the back beforehand. "It's a form of reassurance that goes back to the touch of the caregiver when you were a child," he says.

Field's team have been carrying out research during the lockdown: 26 per cent of the 100 people they surveyed told them they felt very deprived of touch, and 16 per cent moderately. Of the sample, 97 per cent also reported sleep disturbances. "When you move the skin you increase serotonin," explains Field. Low serotonin has been linked to insomnia, anxiety, and depression. "If you move the skin before going to bed, you'll have deeper sleep, which is critical because Substance P is emitted during deep sleep." (Substance P is a neurotransmitter that affects pain perception, stress, and our emotional responses.)

Like so many things in life, we do not realise how much we depend on human touch until we can no longer have it. "I'm normally happy living on my own," says Sarah, a 40-year-old human resources professional from Reading. "I love having my own space." I found Sarah after coming across her increasingly forlorn posts on social media. On March 23, Sarah wrote on Facebook: "I'm going to hug you all so hard when restrictions are lifted. I will TRY not to burst you, but no promises." On April 12, she added: "HUGS FOR EVERYONE WHEN THIS IS OVER." A few days later, a more plaintive note. "I've been super teary today," she wrote on Twitter on March 18. "I live alone and the thought of not getting a hug for anyone for MONTHS is desperate."

For Sarah, her coronavirus-induced skin hunger has felt like grief. "I feel bereft," she says. "I'm really emotional. I feel sad and stressed and quite down about it." She can remember the exact date someone last touched her: March 15. A friend had been staying with her and gave her a hug as he was leaving. Aside from that embrace, Sarah has not touched another living thing apart from her neighbour's cat, which occasionally creeps into her garden and permits her petting, and some geese she fed in a nearby park. Alice has found herself picking up her pet cat far more than usual. "I don't normally feel the need to pick up the cat, because she hates it," Alice says. "But now I pick her up and give her a squeeze."

By petting animals, Sarah and Alice have inadvertently stumbled across an effective skin hunger mitigation strategy. "We know from our research that the massager benefits from massage as much as the massagee," says Field. "So having pets is wonderful. When you pet a dog, you're also moving your own skin and experiencing pressure stimulation."

Much has been made of technology's power to connect us during the pandemic. But technology cannot substitute for skin-on-skin contact. "We can maintain our social relationships through technology," says Gallace. "But although our technology is very advanced in terms of visual and audio rendering, all these technologies lack the sense of touch. There are basically no systems currently available that allow us to interact using touch." He explains that haptic technology - commonly used in sex toys to mimic sensation, or video games - is not sufficiently advanced enough to reproduce the vigour and subtlety, say, of a handshake.

"It's not easy to simulate a handshake," he says. "The sensory modality involves a lot of systems. It's not just the receptors on the skin, but also the strength of the handshake. You can't reproduce that easily. There are systems that reproduce similar forces, but they are not widespread, and the quality of the sensation produced is low. So far, there is nothing that allows us to reproduce a caress."

But there are strategies to reduce skin hunger for those self-isolating alone. "Get as much exercise as you can," Field says. "Simply walking around your room stimulates the pressure receptors in your feet. Give yourself a scalp massage, or rub moisturiser into your face. These are all different ways people can move their skin."

Still, there are only so many Zoom yoga classes you can do to pass the time. At some point, you have to lean into the skin hunger and accept that we'll probably be living in a no-contact society until we have a coronavirus vaccine. And perhaps even after that: after so long treating each other as pariahs, will we really go back to how things were before? Field is fearful that coronavirus may push us even further into a no-touch society long-term. "I suspect when this is over a lot of people will still be keeping social distancing," she says. Alice was in a supermarket recently when someone brushed past her: the unexpected contact made her jump.

Alice has become attuned to her fellow skin-hungry solo lockdowners: she can sense their craving for human contact as keenly as she can feel her own. On a recent walk, she started talking with an older woman who was standing alone in her front garden. Alice felt that she'd been standing there for a while, looking for someone - anyone - to talk to. After chatting with her for a while, the woman reached out her hand. "She said, 'Come here darling,' and tried to give me a handshake," Alice remembers. Alice looked at her with empathy. "I said, 'I'm so sorry, but I really can't.'"

Walking away, Alice felt horrible about rejecting that yearning for human touch, for a simple hand squeeze. "I felt really bad," Alice says. "Because I knew why she wanted it. I wanted it too."