K. H. Grobman

Infant habituation research explained with a magic trick where one of many balloons does not pop.

Infant Habituation & Dishabituation

A Balloon Magic Trick

I created this activity based on an old magic trick to illustrate how we can find out someone's conceptual knowledge from only their non-verbal reactions. Begin class with two discussion questions: How can I find out what you know? (Tests.) But what if you were a baby who could not do a test, or even speak. How can I find out what you know? Let's consider your knowledge of balloons.

You (or volunteers) blew up six balloons before class. Pull out a giant pin. I use a large sewing needle. Pop the first balloon and note their large reaction. Pop the next (within seconds of the first). Note how their reaction is large but not as much. Keep popping balloons 3, 4, and 5 a few seconds apart always emphasizing how much less they are reacting each time.

Now pop balloon 6. The pin stays stuck in the balloon but does not pop! Students often laugh. Note their big reaction.

Recap stuents' experience with the balloons. They became accustomed (habituated) to balloons popping and had a big reaction (dishabituation) when their expectation was violated. Just from their reactions, big or little, we can see that you know pins touching balloons make them pop. Obviously college students can share their understanding in complex ways like language. Infants can not. But can we use infants' reactions to get inside their thinking? Use this as a bridge to discuss research on conceptual development during infancy (e.g., Baillergeon).

Text on key PowerPoint Slides: As we are exposed to a stimulus repeatedly, our attention is less drawn to it. We habituate to the stimulus. When a stimulus is new to us, our attention is drawn to it. If we had just been habituated (bored), and our attention is renewed, then we have dishabituated. We can only dishabituate if, on some level, we know that the new stimulus is different from the preceding stimuli. The more novel a stimulus is, the more we dishabituate to it.

Magic Trick: How does the magic trick work? How come the balloon did not pop but just remained fully blown up with a pin in it? Before class blow up one balloon. Where you would normally stick a pin, put an "X" from two small strips of transparent tape. From their seats, students can not see the tape. When you put a pin into the tape, it won't pop.