Acquisition in psychology refers to the initial stage of learning when a behavior is first being acquired. It is the process where a new behavior is introduced and gradually strengthened, leading to a conditioned response. Acquisition is a term used in both classical and operant conditioning. In classical conditioning, a stimulus that naturally triggers a response is presented along with a second stimulus that is neutral. During the acquisition phase, the two stimuli are repeatedly paired. Eventually, the previously neutral stimulus will also trigger the response. In operant conditioning, acquisition refers to how long it takes for the target behavior to be established.

Factors that can influence the acquisition process include the contiguity between the conditioned stimulus and the unconditioned stimulus, the intensity of the stimuli, and the individuals motivation and attention. Understanding the acquisition process is important for psychologists, educators, and marketers as it sheds light on how behaviors are formed, how habits develop, and how responses can be modified or changed. The study of acquisition dates back to the early experiments of classical conditioning by Ivan Pavlov and the operant conditioning work of B.F. Skinner.