ahundredtimes - being a mother isn't just a chore, it's a relationship. Children learn about the world, about regulating thier emotions, about themselves, THROUGH their relationships with those closest to them.
From "Why Love Matters" (explains it better than I can
"Human babies, like all mammals, are born wired for survival, but uniquely, we are wired to do so through other people. By smiling cutely long before they can walk or talk, babies ensure that the adults in their lives are sufficiently besotted to forgive them the sleepless nights and want to keep them alive. Being smiled at in return teaches the baby the rewards of communication and primes the infant brain for more. Good parenting isn't just nice for the baby; it leads to good development of the baby's prefrontal cortex, which in turn enables the growing child to develop self-control and empathy, and to feel connected to others. Interaction, it turns out, is the high road from merely human to fully humane. "
The person who is most responsive and tuned in to a baby is generally the person who is most fully emotionally engaged with them. Why do you think people say 'nobody understands my child the way I do?'. Sue Gerhardt is saying that children need this type of highly responsive care in the first few years of life for optimal emotional health in later life.