What is seen background for behaviorism? (e.g., positivism)

The background for behaviorism is British empiricism and associationism.

Behaviorism is a theoretical approach in psychology that emphasizes the study of observable behavior over the study of mind. It is largely influenced by British empiricism and associationism. British empiricism is a philosophical belief that knowledge comes only or primarily from sensory experience. It argues that all ideas and knowledge are derived from experience and perception. Associationism, on the other hand, is a theory of how mental processes work, suggesting that ideas and experiences are connected in the mind through association. Behaviorism, therefore, focuses on observable behaviors and the ways in which they are learned and modified through association.