Touch for Social Engagement and Therapy: A Narrative Review

Abstract

This narrative review includes summaries of research on touch for social engagement and for therapy. Touch for social engagement includes greeting touch, affectionate touch and buffers for touch deprivation. Typical greeting behaviors including shaking hands and hugging were superseded by fist and elbow bumping following safety concerns during COVID-19 lockdowns. Affectionate touch as in handholding, cuddling, caressing and kissing have received less recent research attention likely because of the difficulty recruiting participants for affectionate touch during COVID. Instead, touch deprivation has been common including data suggesting that 60% reported being touch deprived during COVID lockdowns, only 21 % of children were being touched a lot and only 38% of partners were being touched a lot. This level of touch deprivation may have preceded COVID based on an airport gate study showing that people were only touching 4% of their waiting time as they were spending most of their time on cell phones scrolling and texting. Although natural activities have been noted to compensate for touch deprivation such as exercise, several studies have attempted to simulate social touch in robots. Touch as therapy has included several different types of touch including cuddling and handholding during painful procedures and massage therapy for innumerable medical and psychiatric conditions. The underlying mechanism for the positive effects of touch involves the stimulation of pressure receptors, as in moving the skin, resulting in a slowing of the nervous system including decreased heart rate, increased heart rate variability, less stress hormone (cortisol), and the increased production of healthy neurotransmitters and natural killer cells to ward off bacterial, viral and cancer cells.