Next time you get a manicure, pat yourself on the back (when you’re nails are dry, of course). Why? Because spa activities like manicures and massages—a form of calming “social” pampering from someone else—are actually a much-needed investment in your wellbeing! The proof is in the primates: Research shows that being groomed is measurably relaxing to primates, lowering the heart rate, reducing stress and boosting endorphins in the brain. So much so that if those endorphins are chemically blocked, those same monkeys beg for even more grooming. As always, we all just want to feel calm and pampered and loved—and, yup, any excuse for a weekly mani is a welcome one.