At twenty-two months Ava began to have opinions about fairness. Not abstract fairness, not the concept. Specific, immediate fairness, applied to every situation she observed. If Marcus got a larger piece of something than I did she noted it. If I got more time with something she wanted than she did she noted that too. She had a word for the state she found unacceptable, which was no fair, delivered with the conviction of a senior counsel. "Where did she learn that?" Marcus asked. "From living with two people who talk about fairness constantly," I said. He thought about that. "We do." "We had to learn to," I said. "She's starting with it already." Ava applied her sense of fairness to everything, including her own behavior. If she had taken a toy from someone at the childminder's she c

