Will power. Some people have it. Some people cave in. (I'm usually the latter of the two.)
Reading about the Marshmallow Experiment (loose nickname) involving 4 year-old kids and will power, it seems that the ability to delay gratification may have benefits later in life. Forty years ago, researchers gave each child a serving of a marshmallow, a pretzel, or a cookie. The kids were told that they could eat what they were given immediately. If they waited, though, they would be given an additional treat.
Many of them had adorable conniption fits while trying to resist the marshmallow's fluffy temptation. Many gave in after several minutes. A few were able to wait over half an hour for the researcher to return with the extra sweet. The ones who demonstrated will power as children, as the Slate article notes, became adults who were better at planning, could handle stress, and were less likely to be overweight. Best of all, researchers found that will power wasn't a magical ability, but something that can be attained. Learning to delay gratification requires strategy.
Speakers, the Marshmallow Experiment can be a great example that illustrates the power of temptation and the benefit of will power. Interpers, check out the more detailed account in The New Yorker. Maybe you can channel the kids' reactions to temptation ("Some cover their eyes with their hands or turn around so that they can’t
see the tray. Others start kicking the desk, or tug on their pigtails,
or stroke the marshmallow as if it were a tiny stuffed animal.") for your next D.I.