For years it seemed that if I was more affectionate with my kids, they were less likely to get sick. I wondered if it was in my mind, if there was a causal relationship, or if being affectionate correlated with better meals and a calmer schedule in general. Then I read about a famous study where participants watched a movie about Mother Theresa, and the immune factors in their saliva were elevated for several hours. We also know that affection reduces cortisol, a stress-coping hormone, and cortisol isn't great for the immune system. (This deserves a post in itself.) We also have studies showing that social connection is more predictive of health than weight, high blood pressure, exercise, alcohol, or smoking a couple of packs a week. So yes, hugging the kids probably does boost their immune systems. If the effect can be documented so easily with adults, how much more powerful should it be with kids?