Who is running our experiments? The influence of experimenter identity in the marshmallow task

While developmental researchers take great care to report on the characteristics of their participants, they rarely report on the characteristics of their experimenter(s). This is surprising, given the real potential for experimenter identity (e.g., gender, race, age, etc.), especially as it relates to children’s identities, to influence children’s behavior in experiments. In the current study, we investigate how experimenter identity (as signaled by language and race cues) influences 3- to 5-year-old children’s (N = 159) behavior in the famous marshmallow task. Results show that experimenter identity indeed influenced children’s wait times in the marshmallow task; specifically, we found that racial mismatch between experimenter and child led to longer wait times, and in an exploratory analysis, we found that this effect was exaggerated by an additional mismatch in accent. We thus reveal a previously overlooked factor that may influence children’s behavior in a delayed gratification task—experimenter identity—and discuss the important implications of these findings for developmental research more broadly.