What type of experimental design was used in the Yamamoto method?

The Yamamoto study utilized a repeated measures design, which involves using the same participants across multiple conditions or trials. This design allows researchers to see differences in behavior or responses within the same individuals, reducing the variability that can arise from comparing different individuals across conditions. In the context of Yamamoto's research, which focused on chimpanzee behavior in cooperative tasks, using a repeated measures design enabled the researchers to assess how the same chimpanzees responded under different circumstances, providing clearer insights into their cognitive abilities and social interactions.

This method is particularly advantageous because it helps control for individual differences that could confound results, as each participant serves as their own control. The repeated exposure to varying tasks also allows for a more thorough understanding of the effects being studied, which is essential in exploring complex behaviors such as those seen in social interactions among chimpanzees.