“Babies whose parents responded readily and fully to their cries in the first months of life were, at one year, more independent and intrepid than babies whose parents had ignored their cries. In preschool, the pattern continued—the children whose parents had responded most sensitively to their emotional needs as infants were the most self-reliant. Warm, sensitive parental care, Ainsworth and Bowlby contended, created a “secure base” from which a child could explore the world.”