In what’s become a cross-divisional tradition, the AP Psychology class of Dr. Carragher (“Dr. C”), Human Development Chair, visited the Lower School for a fun experiment that tested Jean Piaget’s theory of cognitive development. Upper School students were partnered with a group of Kindergartners for the activity. Caden Wiener ’26 explained that he and his AP Psych classmates showed the younger students that they were pouring the same amount of water into two different-shaped vessels, and then asked if they could agree that there was the same amount of water in both the short and tall glasses, despite the visual illusion that one had more than the other. “Most of them seemed to get it,” he said. 

The idea was also demonstrated using the same amounts of Play-Doh rolled into different shapes. Ella Mansager ’26 said Dr. C’s class ran this experiment last year with preschoolers, many of whom thought the amount of water or Play-Doh did change. Ella noted she was able to observe a shift in the perception of students who were a year older. “It’s really cool to see how much they’ve developed in a short time,” she said. Proof that small shifts = big results!