One limitation of using infants is that babies cannot communicate so we must make inferences based on their behaviour. This means that it is subjective and inferences could've been drawn to help the study. Babies are unpredictable so we have an issue with intentionality because there is no way to know if their behaviour was deliberate for the study or if it was just a coincidence. For example, 53 babies were withdrawn from Meltzoff and Moore's study for reasons like sleeping, crying, spitting etc. This shows how unpredictable babies behaviour is.