This chapter covers the basic processes of learning, which include habituation, classical conditioning, operant conditioning, observational learning, and biological and cognitive perspectives on learning.

Psychologists have focused both on how we learn and why we learn. Ethologists focused on the functions of behavior, particularly its adaptive significance; its influence on an organisms' chances of survival and reproduction. Research has suggested that the environment shapes behavior through both personal adaptation and species adaptation. When we enter into environments, the environment shapes our personal behavior. Similarly, the biology of a species is shaped through the natural selection of behaviors that help members of the species adapt to the environment. According to evolutionary psychologists, the human brain has acquired the capacity to perform psychological functions that historically have helped members of our species to survive and reproduce.

The simplest type of learning process may be habituation, the decrease in response strength to a repeated stimulus. By learning not to respond to familiar stimuli, an organism may conserve resources to pay attention to important stimuli.

Classical conditioning, in which an organism learns to associate two stimuli such that one stimulus comes to produce a response that only the other previously did, became famous through the work of the Russian physiologist Ivan Pavlov with the salivary response of dogs. A stimulus that reflexively produces a response is called an unconditioned stimulus (UCS), and the response is called an unconditioned response (UCR). The stimulus repeatedly paired with the UCS that comes to produce the response is called the conditioned stimulus (CS), and the response is then known as the conditioned response (CR). This entire process is known as acquisition. Forward, short-delay conditioning appears to work best. In this procedure the CS is presented first and is still present when the UCS appears. Extinction occurs when the CS is repeatedly presented without the UCS, such that the response strength diminishes significantly. For example, if a dog has been conditioned to salivate in response to a bell (CS) paired with food (UCS), but the bell is then repeatedly sounded without the food being given to the dog, the dog will stop salivating.

Occasionally, a response that has been extinguished will reappear after some time in response to the old CS, a process called spontaneous recovery. Once a CR is acquired, an organism may respond to similar stimuli in the same way, a process called stimulus generalization. The ability to discriminate between stimuli occurs when an organism responds differently to stimuli. When a neutral stimulus comes to produce a response through pairing with an already established CS, higher-order conditioning has occurred. Many examples of this can be seen in everyday life. For example, politicians who appear in front of large American flags are using higher-order conditioning to influence the development of attitudes toward them. Classical conditioning has other applied aspects. The process can be used to both influence the acquisition and elimination of fear. Classical conditioning processes may explain our attraction and aversion to other people, and can be associated with symptoms of allergies and other illness.

Operantly conditioned responses are emitted (voluntarily) rather than elicited like classically conditioned responses are, and they are influenced through their consequences. E.L. Thorndike's Law of Effect says that in a given situation, a response followed by a satisfying consequence will become more likely to occur, whereas a response followed by an unsatisfying consequence will become less likely to occur. The term operant behavior was coined by B.F. Skinner to describe how an organism operates on its environment to get what it wants and to avoid what it doesn't want. Skinner's analysis of operant behavior involved studying the antecedents (A) of the behavior, the behavior emitted (B), and the consequences (C) of the behavior. In operant conditioning, the organism learns an association between the behavior and its consequences. The antecedent conditions come to signal that a certain consequence will follow if a certain behavior is emitted.

Reinforcement and punishment are the consequences that affect the likelihood of a response under the antecedent conditions. Reinforcement strengthens a response that precedes it, whereas punishment decreases the strength of a response that precedes it. Primary reinforcers, such as food and water, are stimuli that satisfy biological needs. Secondary reinforcers, such as money, are conditioned reinforcers because they become associated with primary reinforcers. For example, money can be used to buy food. Negative reinforcement is not the same thing as punishment. Negative reinforcement occurs when the avoidance or removal of a stimulus results in a strengthened response. For example, we use umbrellas because they prevent us from getting wet. Punishment (often called aversive punishment) is an aversive stimulus, such as a slap or rebuke, that serves to weaken a response. In response cost, a response is weakened by the removal of a stimulus. For example, taking away TV privileges or car keys is a response cost technique that parents may use to decrease undesirable behavior in their children.

Operant conditioning can be used to shape behavior by rewarding successive approximations of the behavior. Similarly, chaining is used to condition complex behaviors. The last step of the behavior chain is trained first, and the prior step is reinforced by the ability to perform the next one until the entire chain of behavior is performed. Generalization and discrimination work with operant conditioning much like they work with classical conditioning. Operant generalization occurs when an operant response occurs to a new antecedent stimulus similar to an old one. Operant discrimination occurs when an operant response will occur to one antecedent stimulus but not to another.

Schedules of reinforcement influence much of operant behavior. On a continuous schedule, every response is reinforced, while on a partial schedule, only some responses are reinforced. There are both fixed and interval schedules as well as both ratio and interval schedules. On a fixed-ratio schedule, reinforcement is given after a certain number of responses. On a variable-ratio schedule (e.g., VR-6), reinforcement is given after an average number of responses (e.g., sometimes after 3, sometimes after 6, sometimes after 9). On a fixed-interval schedule, the first response that occurs after a certain amount of time is reinforced. Finally, on a variable-interval schedule, the first response after a variable amount of time is reinforced. Ratio schedules tend to produce the highest rate of responding. Following reinforcement, there is typically a pause in responding, which is referred to as a "scallop" on graphs of response rates. Like classical conditioning, operant conditioning has many applications. Skinner's work gave rise to the field of applied behavior analysis, which combines the behavioral approach with the scientific method in an attempt to solve individual and societal problems through the use of operant conditioning techniques.

Observational learning occurs by observing the behavior of a model. Albert Bandura outlined observational learning, or modeling, as a four-step process: attention, retention, reproduction, and motivation.

Biology asserts certain limits on learning. Martin Seligman's concept of preparedness suggests that animals are biologically "prewired" to learn behaviors related to their survival as a species. For example, animals develop conditioned taste aversions to learn to avoid foods and liquids that are bad for them. Similarly, animals may be prepared to fear certain stimuli. This fear then helps them to avoid or escape the stimuli, thus increasing their chances of survival and reproduction. Some responses are difficult to operantly condition because of instinctive drift, the tendency of animals to engage in instinctive behavior regardless of their training. Biology also affects animals' ability to learn through the action of brain structures like the hypothalamus and through neurotransmitters like dopamine.

Cognition also affects learning. Cognitive models are known as S-O-R models: the initial "O" represents the influence of cognitive processes as an intermediate step between stimulus and response. The expectancy model, for instance, argues that in classical conditioning the CS produces an expectancy (cognition) that the UCS will occur. Cognition is also present in operant conditioning. Cognitive theorists emphasize that organisms develop an awareness, or expectancy, of the relationship between their behavior and its consequences.