Re:Experiment needs a control (Score 1)

This is a very well known study in the developmental psychology field and you can rest assured that there was a control group. If there wasn't then the results obviously couldn't be statistically significant, which is the entire point of experimental psychology fields, like developmental psychology. Precise details about the materials, methods, and descriptive and inferential statistics are provided in the original journal article. There is really no need in discussing such things when presenting to a non-specialist audience. This is effectively a dumbed down version of the real study, which is exactly the kind of presentation a physicist or geneticist would deliver for material from their field.