Reasoning About Groups

Reasoning About Groups

Berkeley Early Learning Lab (UC Berkeley)

Who Can Participate

For babies ages 16 to 20 months who reside in the US. Each participant can only participate in this study once.

What Happens

During the study, your baby will sit on your lap or a high chair and watch short movies with sounds. First, your baby will see movies of different characters tossing candies into boxes at different speeds. Then, they will see a group of different characters move towards the boxes in a way that either matches the tossing speed (more characters go towards the faster tosser) or a way that does not match the tossing speed (more characters go towards the slower tosser).

What We're Studying

This study investigates babies’ ability to use probabilities to make judgements, and whether they expect behavior to match probabilities. For example, if we show babies that one character tosses candies into a box twice as fast as another character, do they expect twice as many kids to go to the faster tosser than to the slower tosser? This study will help us learn what kinds of information babies use when thinking about the world around them.


15 minutes


Within a week after you participate in this study, we will email you a $5 gift card which you can redeem at To be eligible for the gift card: 1) your child must be in the age range for this study, 2) you need to submit a valid consent statement, and 3) we need to see that there is a child with you. You and your child do not need to finish the whole study to receive the gift card; however, if this is the case, please let the researchers know so that you can receive your compensation.

This study is conducted by Fei Xu (contact:

Would you like to participate in this study?