My two year-old daughter Talia is picking up the finer points of negotiation. Last Sunday morning she managed to find two candy bars leftover from Halloween. I said, “sweetie, you can’t eat those now because it’s breakfast time”. She said she wanted to hold them, and did just that for the next hour. She raised the stakes when we found our way to the kitchen to look for food. “Wanna eat this”, she said, holding up the candy bars. Again I said, no, these are for later, after breakfast. She handed me one of the bars, looked me in the eye, and with a conciliatory but firm tone said, “One. Eat one bar”.