Is it true that laughing can make us healthier?

It's undoubtedly the best medicine. For one thing, it's exercise. It activates the cardiovascular system, so heart rate and blood pressure increase, then the arteries dilate, causing blood pressure to fall again. Repeated short, strong contractions of the chest muscles, diaphragm and abdomen increase blood flow into our internal organs, and forced respiration--the ha! ha!--makes sure that this blood is well oxygenated. Muscle tension decreases, and indeed we may temporarily lose control of our limbs, as in the expression "weak with laughter". It may also release brain endorphins, reducing sensitivity to pain and boosting endurance and pleasurable sensations. Some studies suggest that laughter affects the immune system by reducing the production of hormones associated with stress, and that when you laugh the immune system produces more T-cells. But no rigorously controlled studies have confirmed these effects. Laughter's social role is definitely important. I'm very concerned that today's children may be heading for a whole lot of social ills because their play and leisure time is so isolated and they lose out on lots of chances for laughter.

When children stare at computer screens, rather than laughing with each other, this is at odds with what's natural for them. Natural social behaviour in children is playful behaviour, and in such situations laughter indicates that make-believe aggression is just fun, not for real, and this is an important way in which children form positive emotional bonds, gain new social skills and generally start to move from childhood to adulthood. I think parents need to be very careful to ensure that their children play in groups, with both peers and adults, and laugh more.