Blair found that environmental risks, like family turmoil and chaos and crowding, did have a big effect on children’s cortisol levels—but only when their mothers were inattentive or unresponsive. When mothers scored high on measures of responsiveness, the impact of those environmental factors on their children seemed almost to disappear. High-quality mothering, in other words, can act as a powerful buffer against the damage that adversity inflicts on a child’s stress-response system, much as the dams’ licking and grooming seemed to protect their pups.
