1. a psychologist or scientist who studies behavior, especially one who believes that psychology should focus on observable actions rather than internal mental states
Usage: chiefly British spelling; American English typically uses 'behaviorist'; academic/scientific term

Examples

• The behaviouralist conducted experiments to understand how animals learn through reinforcement.
• Early behaviouralists rejected the study of consciousness as unscientific.
• As a behaviouralist, she focused on measuring observable responses rather than subjective experiences.
• The behaviouralist approach dominated psychology in the mid-twentieth century.
• Many modern psychologists combine behaviouralist principles with cognitive science.