And without it, we're in danger of becoming un-glued. And there's plenty of science to back that up. In the 1950s, the University of Wisconsin psychologist Harry Harlow showed that baby rhesus monkeys raised by surrogate mothers preferred one that was made of soft terrycloth but offered no food to one that had food but was made of wire. Touch was more important than food!

And studies a few years ago at Brigham Young University demonstrated that chronic social isolation increases the risk of mortality by almost 30 percent, which will hit hardest those who are already having problems with, say, social anxiety, depression, loneliness, or substance abuse.

On the other (well-washed) hand, touch has been shown to be intimately related to well-being and stress reduction, certainly in its ability to strengthen the immune system, and in the case of shared hugs, in its protective effect against respiratory infections—both of which we could use right about now.

Touch was the first of the senses to come into being at the top of the evolutionary hour, and like the first single-celled creatures, we, too, are surrounded by a membrane—the skin, largest organ in the body—that mediates all our tactile exchanges with the outside world (and keeps the inside world from spilling out). The skin is both a barrier and a bridge, a conveyor of both pain and pleasure, and exquisitely sensitive to touch, every square inch of it endowed with 1,000 nerve endings.

And that touch has salutary effects all along the developmental arc. Premature newborns who receive just three 15-minute sessions of touch therapy a day for five to 10 days gain almost 50 percent more weight than preemies who receive standard medical treatment. Students whose teachers pat them in a friendly (and appropriate) way are three times more likely to speak up in class. NBA basketball teams whose players engage in more celebratory touch—high-fives, chest bumps, pats on the rear-end—win more games and play in a more cooperative fashion than teams that don't. And Alzheimer’s patients who are offered gentle touch are better able to relax, make emotional connections with others, and reduce their depression.

Touch is the first of the five senses to develop in utero and the last to go. “Long after our eyes betray us, our hands remain faithful to the world,” says Frederick Sachs, professor of physiology at the University of Buffalo.

Although any experience of loss, disappointment, or disenchantment comes with a certain payload of grief, in most cases (interpersonally speaking), the pandemic doesn't seem to bring on the kind of shell-shocking grief that attends the sudden loss of love, health or freedom. It's a somewhat slower burn, the dawning realization—as the days of distancing turn into weeks and possibly months—that we may be in for a lengthy siege, and the freedom to socialize at will that we take for granted will literally be kept at arm's length from us, along with many of our loved ones.