Final answer:
The behaviorists, such as John B. Watson and B.F. Skinner, emphasized the study of observable behavior, focusing on measurable actions to make psychology an objective science.
Step-by-step explanation:
The behaviorists emphasized that psychology should only study observable behavior. This perspective, rooted in the work of psychologists such as John B. Watson and B.F. Skinner, positioned itself against the study of consciousness and internal mental processes. Behaviorism focused on external, measurable actions and reactions rather than delving into the mind's unobservable cognitive processes. During its most influential period, behaviorism sought to make psychology an objective science through the precise study of conditioned responses and reinforcements. This controlled approach was a response to more subjective methods of inquiry prevalent at the time, pushing psychology to focus on what could be seen and measured—namely, behavior and how it could be conditioned and modified through environmental interactions.