In Teju Cole’s novel Open City, Julius, the Nigerian doctor whom we follow as he wanders around Manhattan, describes going to a tailor’s shop. “For me, the intimate wonder of getting measured for clothes was like that of getting your hair cut, or feeling the warm touch of the doctor’s hand nestled against your throat as he took your temperature,” he writes. “These were the rare cases in which you gave permission to a stranger to enter your personal space.” His tentative “for me” reveals the unspoken nature of the pleasure that’s found in the touch of a stranger; as if admitting so exposes a lack of intimacy in the rest of our lives.

But it is a common pleasure. The pseudoscientific phenomenon of ASMR (autonomous sensory meridian response, the brain-tingling feeling c...