AP Psychology Unit 5 Notes: Cognitive Psychology

February 12, 2024
AP Psychology Study Notes: Unit 5

Get ready for the AP Psychology exam by reviewing what is covered in Unit 5, including key terms and people. These AP Psychology study notes should be used to supplement what you’re learning in your AP Psych class. More study strategies and expert tips can be found in our latest AP Psychology Test Prep Book.

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AP Psychology: Unit 5 Summary

This unit focuses on some of the most important concepts in an introductory psychology class. These concepts are important because they represent a significant number of questions on the AP Psychology test, and because concepts covered in this unit can help you study and learn more effectively. Most of this unit is devoted to concepts related to memory. Toward the end of the unit, shorter sections are devoted to language and thinking/creativity.


The central question of memory research is: What causes us to remember what we remember and to forget what we forget? Memory is defined by researchers as any indication that learning has persisted over time. You might remember the bully who pushed you into the mud in second grade but forget your appointment with the school counselor. What are the processes that determine which events stick in our memories? Why and how do we lose information from memory? How accurate are our memories? Researchers do not have the final answers to any of these questions. However, models and principles of memory have emerged from the research that give us insight into how we remember.

Testing and Individual Differences 

We all take many standardized tests and receive scores that tell us how we perform. Given the world in which we have grown up, it is almost unimaginable that there ever could have been a time during which people’s mental abilities were not measured and tested. Francis Galton was a pioneer in the study of human intelligence and testing, who initiated the use of surveys for collecting data and developed and applied statistics toward its analysis. Review what makes for a good test, how to interpret your scores on such tests, and what different kinds of tests exist. Then we will focus on one of the most tested characteristics of all, intelligence.

AP Psychology: Unit 5 Key Terms & People

Below, we describe some of the Unit 5 key terms and people you should review ahead of the AP Psychology exam.

  • Sensory memory: The first stop for external events is sensory memory. It is a split-second holding tank for incoming sensory information. All the information your senses are processing right now is held in sensory memory for a very short period of time (less than a second).
  • Explicit memories: Explicit memories (also called declarative memories) are what we usually think of first. They are the conscious memories of facts or events we actively tried to remember. When you study this chapter, you try to form explicit memories about the memory theories.
  • Implicit memories: Implicit memories (also called nondeclarative memories) are unintentional memories that we might not even realize we have. For example, while you are helping your friend clean her house, you might find that you have implicit memories about how to scrub a floor properly after watching your parents do it for so many years.
  • Recognition: Recognition is the process of matching a current event or fact with one already in memory (e.g., “Have I smelled this smell before?”). 
  • Recall: Recall is retrieving a memory with an external cue (e.g., “What does my Aunt Beki’s perfume smell like?”). Studies have identified several factors that influence why we can retrieve some memories and why we forget others.
  • Constructed memory: A constructed (or reconstructed) memory can report false details of a real event or might even be a recollection of an event that never occurred. Studies show that leading questions can easily influence us to recall false details, and questioners can create an entirely new memory by repeatedly asking insistent questions. Constructed memories feel like accurate memories to the person recalling them. The only way to differentiate between a false and a real memory is through other types of evidence, such as physical evidence or other validated reports of the event.
  • Phonemes: Phonemes are the smallest units of sound used in a language. English speakers use approximately 44 phonemes. If you have studied another language or if your primary language is not English, you have experience with other phonemes.
  • Morphemes: A morpheme is the smallest unit of meaningful sound. Morphemes can be words, such as a and but, or they can be parts of words, such as the prefixes an- and pre-. So, language consists of phonemes put together to become morphemes, which make up words.
  • Noam Chomsky: Researcher Noam Chomsky theorized that humans are born with a language acquisition device, the ability to learn a language rapidly as children (this is also called the nativist theory of language acquisition). Chomsky pointed to the retarded development of language in cases of children deprived of exposure to language during childhood. He theorized that a critical period (a window of opportunity during which we must learn a skill, or our development will permanently suffer) for learning language may exist.
  • Heuristic: A heuristic is a rule of thumb—a rule that is generally, but not always, true that we can use to make a judgment in a situation. The following shows two specific examples of heuristics.
  • Rigidity: Rigidity (also called mental set) refers to the tendency to fall into established thought patterns. Most people will use solutions or past experience to try to solve novel problems. Occasionally, this tendency prevents them from seeing a novel solution.
  • Confirmation bias: Another obstacle to successful problem solving is confirmation bias. Many studies show that we tend to look for evidence that confirms our beliefs and ignore evidence that contradicts what we think is true. As a consequence, we may miss evidence important to finding the correct solution.
  • Standardized: When we say that a test is standardized, we mean that the test items have been piloted on a similar population of people as those who are meant to take the test and that achievement norms have been established.
  • Reliability: Reliability refers to the repeatability or consistency of the test as a means of measurement. For instance, if you were to take a test three times that purportedly determined what career you should pursue, and on each occasion you received radically different recommendations, you might question the reliability of the test.
  • Validity: A test is valid when it measures what it is supposed to measure. Validity is often referred to as the accuracy of a test. A personality test is valid if it truly measures an individual’s personality, and the career inventory described above is valid only if it actually measures for what jobs a person is best suited. The latter example should serve to highlight an important point: a test cannot be valid if it is not reliable.
  • Fluid intelligence: Fluid intelligence refers to our ability to solve abstract problems and pick up new information and skills.
  • Crystallized intelligence: Crystallized intelligence involves using knowledge accumulated over time.
  • Stanford-Binet IQ: IQ stands for intelligence quotient. A person’s IQ score on this test is computed by dividing the person’s mental age by his or her chronological age and multiplying by 100.
  • Heritability: An important term that researchers use in discussing the effects of nature and nurture is heritability. Heritability is a measure of how much of a trait’s variation is explained by genetic factors. Heritability can range from 0 to 1, where 0 indicates that the environment is totally responsible for differences in the trait and 1 means that all of the variation in the trait can be accounted for genetically.
  • Flynn effect: Performance on intelligence tests has been increasing steadily throughout the century, a finding known as the Flynn effect. Since the gene pool has remained relatively stable, this finding suggests that environmental factors such as nutrition, education, and, perhaps, television and video games play a role in intelligence.

Next, test your AP Psychology Unit 5 knowledge using our free Key Terms Worksheets!