Fuel vs. reward

[nancylebov]

http://mrissa.livejournal.com/486037.html

If you're taking a 4-year-old on an airplane, she might behave herself if you promise her a new puzzle and a new coloring book afterwards if she does, but your odds are better if you give her the puzzle and the coloring book to help her be good on the plane in the first place.

Link thanks to yhlee