History of Psychology

• Behaviourism


  A theoretical orientation based on the premise that scientific psychology should study observable behavior
• Cognitive revolution


  A new approach developed in the late 1950s and early 1960s, directly tied to the development of the computer, that made it seem possible to study internal mental life objectively
• The problem of a psychological science is how to measure mind and consciousness when methods of introspection have limitations
• Psychoanalysis looks at the unconscious mind
• Behaviourism was a reaction against the unobservable, as introspection is not verifiable and subjective rather than objective
• Reflexes


  Examining conditioned reflexes, such as saliva excretion in dogs to a dilute acid stimulus on the tongue
• Pavlov's classical conditioning


  A type of learning in which a neutral stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus
• Unconditioned stimulus


  A stimulus that naturally evokes a response
• Unconditioned response


  The response that is naturally evoked by an unconditioned stimulus
• Conditioned stimulus


  A previously neutral stimulus that, through learning, has acquired the capacity to evoke a response
• Conditioned response


  The response that is evoked by a conditioned stimulus
• Edward Thorndike


  • Focused on the acquisition of behaviour, looking at how cats learned to escape from a puzzle box
  • Proposed the Law of Effect: Behaviour depends on consequence (reward/punishment)
• Stimulus-response (S-R) probabilities


  Learning occurs when there is an increase in positive S-R probabilities, and forgetting occurs when there is a decrease in positive S-R probabilities
• J.B. Watson


  • Founder of behaviourism
  • Wanted a break between philosophy and psychology, believing knowledge should be based on observable phenomena
  • Looked at conditioning with humans, such as conditioning the 'Little Albert' boy to fear a white rat
• Conditioned learning


  Watson believed conditioned learning could account for all kinds of behaviour, including human emotions (except fear, rage and love)
• Watson believed it was the environment that was important, not nature
• B.F. Skinner


  • Developed radical behaviourism and operant conditioning - the modification of behaviour through the use of reinforcers and punishers
  • Believed operant conditioning could explain all behaviour, including training pigeons to play 'ping-pong' and be 'superstitious'
• Operant conditioning


  Learning in which voluntary responses come to be controlled by their consequences: favorable consequences (reinforcers) tend to cause repetition of the preceding behavior, and unfavorable consequences (punishers) tend to discourage behaviors
• Skinner designed the 'air crib' or 'heir conditioner' to make his baby comfortable, confident, mobile, and healthy
• Behaviorism


  A theoretical orientation based on the premise that scientific psychology should study observable behavior, viewing personality as a collection of response tendencies tied to various stimulus situations
• Key behaviorists


  • Ivan Pavlov
  • Edward Thorndike
  • John Watson
  • B.F. Skinner
• Behaviorists wanted to remove mind, consciousness, purpose and cognition from psychology
• Behaviorism has problems explaining behavior that shows purpose, evolutionary constraints on learning, and the unobservable nature of much human experience, as well as its inability to explain natural language
• Cognitive psychology


  An approach that infers central mental processes from observable behaviour, seeing behaviour as goal-directed rather than just reflexive
• The cognitive revolution was directly tied to the development of the computer, which allowed researchers to specify the internal mechanisms that produce behavior
• Information processing


  The cognitive revolution made it seem possible that psychologists could study internal mental life objectively, by modeling storage systems, operations, rules, mental images, and memory representations
• 1956 was a critical year for the cognitive revolution, with the development of artificial intelligence, studies of thinking and cognitive strategies, and the application of signal detection theory to perception
• The cognitive revolution involved an interdisciplinary approach, drawing on AI, math, computer science, language, and neuropsychology
• Chunking


  The process of organizing information into meaningful units, as demonstrated by George Miller's work on the "magic number 7, plus or minus 2"
• Jerome Bruner: '"...an all-out effort to establish meaning as the central concept of psychology. Its aim was to discover and to describe formally the meanings that human beings created out of their encounters with the world, and then to propose hypotheses about what meaning-making processes were implicated."'
• Five ideas that made the cognitive revolution


  • The mental world can be grounded in the physical world by the concepts of information, computation, and feedback
  • The mind is not a blank slate
  • An infinite range of behavior can be generated by finite combinatorial programs in the mind
  • Universal mental mechanisms can underlie superficial variation across cultures
  • The mind is a complex system composed of many interacting parts
• Cognitive psychology allows us to ask questions about how children acquire concepts, how memories are stored and retrieved, how we make sense of causal associations, how cognitive processes relate to brain structure and activity, and how the mind works
• The cognitive revolution has implications for the study of consciousness and artificial intelligence
• There are problems with the idea of free will, as shown by Libet's experiments and Wegner's work on the illusion of conscious will
• Artificial intelligence has made progress, with computers able to rapidly explore possibilities and evaluate them, as demonstrated by Deep Blue beating Kasparov in chess
• Alan Turing's work on the Turing machine and the Turing test raised questions about whether machines can think like humans
• There are concerns about the dangers of AI, such as the spread of fake news by Twitter bots and the moral decisions made by self-driving cars
• Both behaviourism and the cognitive revolution were paradigm shifts that reacted to the previous zeitgeist, with behaviourism rejecting the study of the mind and the cognitive revolution embracing it