Harlow’s Monkey experiments (Harlow & Harlow, 1965) are perhaps the most famous example of research pointing at the primacy of the need for touch. In a series of experiments, Harlow created inanimate surrogate mothers for baby monkeys made from wire and wool. Each infant became attached to its particular “mother,” recognizing its unique face and preferring it above others.
Next, Harlow presented the infants with a soft, cuddly clothed "mother" as well as a wire "mother" located in two separate but attached chambers. Only the wire “mother” held a bottle with food. Harlow found that the monkeys spent far more time next snuggled against the cloth “mother” than they spent with the wire “mother” even though the wire “mother” was the only one with food. Food may be necessary for survival, but touch is what sustains us.
Later in his
career, Harlow carried out perhaps his most controversial study, by cultivating infant monkeys in isolation chambers for up to 24 months. The infant monkeys emerged from isolation deeply disturbed, a finding of which many credit as having started the animal rights movement.
Since Harlow’s experiments, research has uncovered an astonishing number of poor health outcomes that result when we are deprived of touch. The correlation between
anxiety,
depression and stress and touch is large and inversely related. It has been found that touch calms our nervous center and slows down our heartbeat. Human touch also lowers blood pressure as well as cortisol, our stress hormone. It also triggers the release of oxytocin, a hormone known for promoting emotional
bonding to others.