Deepak Chopra, MD, ‘The health benefits of practicing compassion’, http://www.sfgate.com/opinion/chopra/article/The-health-benefits-of-practicing-compassion-6328034.php, SFGate (June 15, 2015).

Lifestyle

The reason a compassionate lifestyle leads to greater psychological well-being may be that the act of giving is equally or more pleasurable than receiving. (…) A recent study found that the pupils of infants’ eyes widened when they saw someone in need—a sign of concern—but their pupils would shrink when they could help that person—or when they saw someone else help, suggesting that they felt better. (…) Adults’ and children’s first impulse is to help others, not to compete with them.