" What could prompt parents to give up sleep, sex, friends, personal time and virtually every other pleasure in life to meet the demands of a small, often irritatingly noisy, incontinent, needy being? The secret is that caring for children is, in many ways, indescribably pleasurable. Our brains reward us for interacting with our children, especially infants: their scent, the cooing sounds they make when they are calm, their smooth skin and especially, their faces are designed to fill us with joy. What we call “cuteness” is actually an evolutionary adaptation that helps ensure that parents will care for their children, that babies will get their needs met, and parents will take on this seemingly thankless task with pleasure. "

― Bruce D. Perry , The Boy Who Was Raised as a Dog: And Other Stories from a Child Psychiatrist's Notebook