Foundational Movements in Psychology: Behaviorism

The development of psychology has been marked by significant figures and movements that have shaped its scientific foundations. Among the pivotal milestones is the emergence of behaviorism, which emphasized the study of observable behavior over inner mental states. John B. Watson, often associated with this movement, famously promoted the idea that psychology should not concern itself with the mind, as it was not directly observable.

In contrast, earlier traditions, such as structuralism and functionalism, laid the groundwork for understanding mental processes. Factors like introspection and the focus on individual perceptions were crucial. However, behaviorism shifted psychological research further into the realm of public observation and environmental interactions.

With this context in mind, which of the following early psychologists is credited with laying the groundwork for the behaviorist movement by advocating the idea that psychology should focus exclusively on observable behavior?