As an infant, Lucy was active, easy to soothe, interested in everything, and able to spend long periods playing by herself. She was happy and energetic, though not as cuddly as some babies, and she soothed herself by sucking and babbling when she became tired or anxious. Her parents of course knew Lucy better than anyone. But they could not have predicted that, at the age of sixteen, she would be outgoing yet slow to make friends, talkative and creative, a follower rather than a leader, prone to feelings of shame but not guilt, and irritability rather than depression, self-centered as are most adolescents, but also eager to please her parents and teachers. What connection was there between Lucy as a baby and Lucy as an adolescent? Where did Lucy's teenage personality come from, if it wasn't there already in infancy?

Her brother Max was a more active and fussy baby, less capable of self-soothing and more reliant on his parents, but sweet and personable when he wasn't distressed. By the age of three, Max would be described as “difficult” in temperament, excessively demanding and prone to anxieties, night terrors, and temper tantrums. At this age his mother alternately became distant or angry when she could not be there for him. By four he was mischievous and sneaky, and by six he was avoided by his peers because he was aggressive and unable to share. One could not predict this sad outcome from Max's demeanor as a baby.