Unseen qualities such as states of mind were not used in this type of psychology, even though we know that the mind plays a part in all advanced animals' behaviors. Behaviourism states that behaviour can be studied without knowing what the physiology of an event is, and without using theories such as that of the mind. By definition, all behaviour can be observed.
Behaviorism also relied on another idea, that all human behaviour was learned. Behaviorists believed that behavior could be explained by classical or operant conditioning. This is learning by feedback from specific actions. However, behaviourists denied the importance of inherited behaviours, instincts, or inherited tendency to behave. They did not believe, or ignored, the idea of heredity, that something can come from a person's genes. This was the idea of the blank slate, that babies are born with a clean, empty mind. The blank slate premise is opposed by modern evolutionary psychology.
Pavlov researched classical conditioning through the use of dogs and their natural ability to salivate, produce water in their mouths. Thorndike and Watson rejected introspective methods, looking at one's own conscious thoughts and feelings. They wanted to restrict psychology to experimental methods. Skinner's research leant mainly on behaviour shaping using positive reinforcement (rewards rather than punishments).
The act of conditioning is when a desired behavior is made through training. This is done by pairing stimuli with a specific behavior. Some behaviors are natural reflexes which people (and animals) are born with. Infants are born with inherited reflexes that help them eat, communicate, and survive. These reflexes are unconditioned, they are not taught to the baby.
Classical conditioning (also known as Pavlovian conditioning) is when a conditioned stimulus causes an unconditioned response. This explains how people gained new responses to different stimuli.
Another example of an unconditioned response is when wind is blown in a person's eyes and they blink automatically to prevent dust or something from getting into them. This is a reflex that is innate.
Fear conditioning is when a previously neutral stimulus is used to elicit fear. One main example is the Little Albert experiment by Watson and Rayner. The researchers tested infants' emotional reactions. They found that Little Albert would react to a loud noise and then consequently conditioned that noise to elicit fear when he saw a white rat. This came to be known as 'conditioned emotional response'. After a period of time, Little Albert would cry when he saw a white rat or anything small and white, even his stuffed animal.
Behaviorism Facts for Kids. Kiddle Encyclopedia.