Unit 2/0 - AP Psychology

Psychology

The scientific study of behavior and mental processes (such as sleep, sensation, perception, cognition, memory, thinking, learning, problem solving, emotion, and motivation). It is a relatively new science established in the late 1800s by Wilhelm Wundt, stemming from philosophy and biology.

Hindsight Bias

The “I knew it all along principle”. The human tendency to believe after learning about an outcome, that we could have predicted or known it all along. This underscores why psychology requires a science-based approach.

Overconfidence

The behavioral tendency to think that we know significantly more than we actually do when estimating our knowledge or predicting outcomes.

Perceiving Order In Random Events

The human tendency to believe we can predict what will happen next based purely on a past sequence of completely random events.

Confirmation bias

A cognitive bias where people actively seek out information that affirms their own existing assumptions and beliefs rather than evaluating evidence objectively

Self-Report Bias

An issue where people provide inaccurate answers and information on assessments due to memory errors, misunderstandings, or subjective framing.

Social Desirability Bias

The tendency for people to answer questions based on what they think makes them look good or what society wants to hear, rather than answering with objective honesty.

Evolutionary Perspective

A lens or point of view focused on how natural selection, adaptation, and the survival of ancestral traits influence modern human behaviors and mental processes

Biological Perspective

A point of view that explains human behavior by looking directly at underlying biological structures, genetics, brain chemistry, anatomy, and hormones.

Psychodynamic Perspective

An approach focusing on unconscious drives, internal conflicts, childhood experiences, and hidden motivations to explain behavior and personality.

Behavioral Perspective

A perspective completely focused on observable, measurable behaviors and how our actions are shaped, learned, or conditioned by environmental stimuli.

Humanistic Perspective

An approach emphasizing human growth potential, self-actualization, free will, and an individual's inherent desire to achieve their personal best.

Cognitive Perspective

A point of view centered on how we encode, process, store, retrieve, and interpret information—essentially studying how the mind thinks, remembers, and reasons.

Socio-Cultural Perspective

An approach examining how our behavior and thinking vary across different situations, social environments, societies, and distinct cultural contexts.

Bio-Psycho-Social Perspective

An integrated, holistic perspective that incorporates biological, psychological, and social-cultural viewpoints to offer a complete, well-rounded explanation of human behavior

Institutional Review Board (IRB)

A governing body composed of at least 5 members (including scientists, non-scientists, and community representatives) that thoroughly reviews research proposals before a study begins to ensure human or animal rights, welfare, and safety are fully protected

Informed Consent

An ethical requirement where participants volunteer to take part in a study after being given enough details about its purpose, procedures, and potential risks to make an educated choice. Participants retain the right to withdraw at any time.

Informed Assent

Consent given by minors themselves alongside the legal consent provided by their parent or guardian, ensuring the child also explicitly agrees to participate in the study

Research Confederates

A type of experimental deception where individuals who are secretly actors pose as ordinary participants or fellow researchers within a study.

Debriefing

An essential post-study procedure where researchers fully explain the true purpose of the study, reveal any hidden deception, answer questions, and alleviate any distress or misconceptions experienced by participants.

Confidentiality

The ethical rule demanding that a participant's personal identity, raw data, and information are strictly protected and never disclosed to the public.

Case Study

An in-depth, detailed analysis of a single individual or specific group, often utilized when an unusual situation cannot be practically or ethically replicated. It provides deep insight but cannot prove causation.

Naturalistic Observation

A non-experimental method where a researcher observes and records behaviors as they naturally unfold in real-world settings in real time without any manipulation or interference

Correlation Study

A research method used to determine if a relationship exists between two distinct factors and to evaluate how strong that relationship is. It explicitly cannot determine cause-and-effect.

Meta-Analysis

A statistical process where researchers combine data from multiple previously published studies on the same topic to yield a single, highly generalizable conclusion

Quantitative Data

Data collection involving numerical measurements, counts, and statistical values (e.g., measuring "how much" using numerical values or Likert Scales).

Qualitative Data

Data collection focusing on descriptive, in-depth narratives, interview responses, and non-numerical insights.

Hypothesis

A testable, clear prediction derived from a theory that specifies relationships between variables and must be falsifiable (capable of being proven wrong when tested).

Variable

Any factor, trait, or condition that can exist in differing amounts or types and can change or be measured within a research study.

Independent Variable (IV)

The specific factor that the experimenter deliberately manipulates, alters, or changes to observe its direct effect.

Dependent Variable (DV)

The behavior or mental process that is measured by the researcher to determine if it changes in response to manipulations of the independent variable.

Operational Definition

A carefully worded statement explaining the exact, measurable procedures, concepts, and details of a study so that future researchers can replicate it precisely.

Experimental Group

The group of participants in an experiment who are exposed to the actual independent variable or treatment being tested.

Control Group

The group of participants who do not receive the independent variable/treatment, serving as a baseline comparison to evaluate the effects of the IV.

Random Assignment

The process of assigning participants to the experimental or control groups purely by chance, giving every participant an equal statistical probability of being placed in either group to control for preexisting differences.

Placebo

An inactive substance or fake treatment (like a sugar pill) designed to look, taste, and feel identical to the active treatment to minimize participant expectations and bias.

Placebo Effect

A real or perceived improvement in a participant's condition or behavior triggered entirely by their belief that they received an active treatment.

Experimenter Bias

Unintentional influence exerted by researchers that skews the collection, execution, or interpretation of data to favor their expected outcome.

Single-Blind Procedure

An experimental process where participants are kept completely unaware of whether they are receiving the active treatment or a placebo, preventing participant expectations from biasing results.

Double-Blind Procedure

An experimental setup where both the participants and the data-collecting researchers are entirely unaware of who received the active treatment versus the placebo, eliminating both participant and experimenter bias.

Correlation

A statistical relationship between two variables, showing how predictably they change together, without active manipulation by a researcher. (Correlation does NOT equal causation).

Scatter Plot

A graph used to display correlational data points along two axes to visually observe trends, directions, and the strength of relationships between two variables

Directionality Problem

A complication in correlational research where it is clear that a relationship exists, but it is impossible to determine which variable is the cause and which is the effect.

Third Variable Problem

Occurs when an unmeasured, hidden variable influences both variables under observation, mistakenly giving the illusion that they have a direct, causal relationship.

Illusory Correlation

The psychological phenomenon where people perceive a relationship between two variables where absolutely no real connection exists (e.g., full moons causing erratic behavior).

Correlation Coefficient

The mathematical value (known as the "r-value") ranging from -1.0 to +1.0 that measures the precise strength and mathematical direction of a correlation.

Measures Of Central Tendency

Descriptive statistical tools used to summarize a single data set by locating the single center or middle value (Mean, Median, and Mode)

Mean

The mathematical average of a data set, calculated by adding all scores together and dividing by the total number of scores. It is highly sensitive to extreme outliers.

Median

The exact physical middle score in a distribution when all data values are arranged in chronological order from lowest to highest. It is highly resistant to outliers

Mode

The data point or score that occurs with the absolute highest frequency within a distribution.

Bimodal Distribution

A specific type of data distribution that contains two separate, distinct modes or high points.

Normal Curve

A symmetrical, bell-shaped distribution curve where the majority of scores fall right in the middle, and the mean, median, and mode are all completely equal.

Skewed Distribution

An asymmetrical distribution curve caused by extreme outlier scores pulling the mean away from the center.

• Positive Skew: A few high outlier scores pull the mean higher (tail points right).

• Negative Skew: A few low outlier scores pull the mean lower (tail points left).

Regression Toward The Mean

The statistical phenomenon where extreme, unusual scores or performances are naturally followed by subsequent scores that revert closer back to the baseline average.

Measures of Variation

Statistical tools used to describe and understand the dispersion, spread, or clustering within a single data set.

Range

A simple measure of variation computed by finding the exact distance between the absolute highest and lowest values in a data set.

Standard Deviation

A sophisticated measure of spread that evaluates exactly how much individual data scores deviate from the mean. Shows how close or spread apart numbers are. In a normal curve, 68% of data falls within 1 SD, 95% within 2 SD, and 99.7% within 3 SD.

Percentile Rank

A descriptive tool indicating the exact percentage of individual scores that fall below a specific given data point.

Inferential Statistics

Statistical methods used to determine if data from a random, representative sample can be legitimately generalized to explain trends in a broader target population.

Generalizability

The extent to which findings, conclusions, and insights from a specific research sample can be accurately applied to an entire population. Supported by large, random, representative samples.

Statistical Significance

A mathematical determination (expressed as a "P-value") indicating whether experimental findings are likely due to a real independent variable effect rather than random chance. Typically, a P-value of less than 5% (p < 0.05) is required.