Museum of Science, Boston

Willpower (HBC)

Can kids' willpower be worn out like a muscle?

Fighting temptation is a notoriously difficult challenge we all face every day. Recent research suggests it gets even harder the more you do it – social psychologists have shown that if you do one thing that requires self-control (such as eating some radishes but not any of the chocolate chip cookies on the next plate over) then you’re worse than usual at a second task also requiring self-control. It seems like our willpower is like the strength of a muscle – as we exercise it, it gets worn out.

In preschool and early childhood, kids are still developing self-control, and we’re curious whether their willpower is similarly exhaustible. To find out, 3-6 year olds will play two games in our study. In both games, children must stop themselves from making an automatic response, a lot like they would do in a game of ‘Simon Says’. One of the games is designed to tax kids’ self-control resources, and the other game is used to measure those resources both before and after. Some kids will play the measurement game, the challenging game, and then the measuring game again. Other kids will just play the measurement game twice in a row.

We predict that, like adults, children have a limited amount of self-control. If this is the case, we expect that the kids who play the challenging game will be worse at the measurement game the second time around because their limited store of self-control is being used up!

This research will help us better understand the limitations of children’s self-control in real-world situations.

Learn about other research related to Human Biology.

This research is conducted by the Laboratory for Developmental Studies at Harvard University

Try it at the Museum

Controlled Actions

Many activities at the Kiosk in the Human Body Connection encourage you and your child to plan and make a prediction about what will happen before trying out the experiment. Can you help your child make a hypothesis before starting the activity? Try carefully using the tools provided at the counter. For children, this requires a lot of self-control! Now try changing only one part of the experiment at a time to see what happens. This is how scientists control variables in their studies.

Try it at Home

Test of wills

Play games with your child that test your self-control. Solve a maze together without peeking at the answer, have a staring contest and see who blinks first, play “Simon Says” or “Red Light, Green Light”, put together a puzzle without looking at the picture on the box.

How long does your child last? Does it get harder for your child to have self-control the longer you play the game, or does he/she get better at it with practice?

Resisting Temptation

Simple things like sitting in class can require a lot of self-control, if you really just want to play outside. Can you think of a situation where you had to resist a temptation or use your self-control? What was it that your natural impulse and why did you have to resist it? How did you use your willpower to avoid giving in? Was it hard to do?