One recent morning, 5-year-old Mia, wearing a flowery blue dress, arrived at the lab with her father and her small plastic purple pony. One of the scenarios was "Sarah owned a peacock as a pet." When asked whether this scene was real or not, Mia immediately answered, "not real." And why is that? "Because nobody owns a peacock," she said. Another scenario—"Julia jumped in the air and never came back down"—also wasn't real because "nobody wants to live in the clouds where they can't see the sky," said Mia.
Her responses are typical for her age, says Dr. Woolley. Early results suggest that 5-year-olds don't yet have the ability to distinguish what is impossible from what is unlikely to happen but could technically happen. In future work, Dr. Woolley and her collaborators plans to investigate whether a researcher acknowledging that the situation is strange alters kids' views of whether the scenario is real.