According to B.F. Skinner, what constitutes mental states?

B.F. Skinner, a prominent figure in behaviorism, posited that mental states should be understood primarily through observable behaviors rather than internal experiences or thoughts. According to Skinner, what we consider mental states do not have an independent existence; instead, they are identified through the patterns of behavior exhibited in response to various stimuli. This emphasis on visible physical behaviors reflects Skinner’s assertion that psychology should focus on what can be empirically observed and measured, rather than speculations about inner psychological processes.

In this framework, behaviors are seen as the primary data for understanding human actions and experiences. Skinner's approach dismisses the idea of mental states being purely internal or private experiences that cannot be directly observed. By prioritizing behaviors, Skinner aligns with the basic tenets of behaviorism, which aims to study and understand human psychology through the lens of external interactions with the environment.