unit 1 psych

Cultural Norms

Shared rules and expectations within a culture that guide behavior. Example: In Japan, bowing is a cultural norm for greeting, while in the U.S., handshakes are more common.

Confirmation Bias

The tendency to search for, interpret, and remember information that confirms preexisting beliefs. Example: A person who believes vaccines are harmful only reads articles supporting that view.

Hindsight Bias

The tendency to believe, after an event has occurred, that one would have predicted it ('I knew it all along'). Example: After a stock market crash, people claim it was obvious it would happen.

Overconfidence

The tendency to overestimate one’s knowledge, abilities, or accuracy. Example: A student is certain they aced an exam but ends up failing.

Independent Variable (IV)

The variable that is manipulated in an experiment. Example: In a study on sleep and memory, the IV is the amount of sleep participants get.

Confounding Variable

An extraneous factor that affects the results, making it unclear if the IV caused the change. Example: In a drug study, if one group exercises more, fitness level could be a confounding variable.

Dependent Variable (DV)

The outcome variable that is measured. Example: In a study on caffeine and alertness, the DV is reaction time on a test.

Random Assignment

Assigning participants to experimental and control groups randomly to minimize bias. Example: Flipping a coin to decide which participants get the new drug vs. a placebo.

Case Study

An in-depth study of one individual or small group. Example: Phineas Gage’s brain injury study helped understand frontal lobe function.

Correlation

A statistical relationship between two variables (does not imply causation). Example: Ice cream sales and drowning deaths both rise in summer (both linked to heat, not each other).

Positive Correlation

Both variables increase or decrease together. Example: More study time is associated with higher test scores.

Negative Correlation

One variable increases while the other decreases. Example: More screen time is linked to lower grades.

Meta-analysis

A statistical technique combining results from multiple studies. Example: Analyzing 50 studies on antidepressants to determine overall effectiveness.

Naturalistic Observation

Observing behavior in a natural environment without interference. Example: Jane Goodall studying chimpanzees in the wild.

Hypothesis

A testable prediction about the relationship between variables. Example: "Students who sleep 8 hours will perform better on exams than those who sleep 4 hours."

Falsifiable

A hypothesis must be able to be proven wrong. Example: "All swans are white" is falsifiable because finding one black swan disproves it.

Operational Definitions

Clearly defining variables in measurable terms. Example: "Aggression" could be operationally defined as "number of punches thrown."

Replication

Repeating a study to confirm results. Example: A famous psychology experiment is repeated with new participants to verify findings.

Central Tendency

A single value describing the center of a data set (mean, median, mode). Example: The average (mean) test score in a class is 75%.

Variation

How spread out the data is (range, standard deviation). Example: One class has test scores from 70-80%, while another has 50-100%.

Percentile Rank

The percentage of scores below a given value. Example: Scoring in the 90th percentile means you did better than 90% of test-takers.

Mean

The arithmetic average of a data set. Example: (2+4+6)/3 = 4.

Median

The middle value in an ordered data set. Example: In [1, 3, 9], the median is 3.

Mode

The most frequently occurring value. Example: In [2, 2, 3, 5], the mode is 2.

Range

The difference between the highest and lowest values. Example: In [5, 10, 15], the range is 10.

Normal Curve

A symmetrical bell-shaped distribution of data. Example: IQ scores follow a normal curve, with most people near 100.

Positive Skew

A distribution with a long tail on the right. Example: Income data, where most people earn modestly but a few earn millions.

Negative Skew

A distribution with a long tail on the left. Example: Exam scores where most students scored high, but a few failed.

Bimodal Distribution

A distribution with two peaks. Example: Height in a group of men and women (two peaks for male/female averages).

Standard Deviation

A measure of how spread out scores are around the mean. Example: A low standard deviation means most scores are close to average.

Regression Toward the Mean

Extreme scores tend to move closer to the average over time. Example: A student who scores 100% on one test may score closer to 80% on the next.

Sample

A subset of a population used in research. Example: Surveying 100 students out of a 1,000-student school.

Population

The entire group researchers are interested in studying. Example: All high school students in the U.S.

Representative Sample

A sample that reflects the characteristics of the population. Example: Polling voters from urban, suburban, and rural areas to predict an election.

Random Sampling

Every member of the population has an equal chance of being selected. Example: Drawing names from a hat to pick survey participants.

Convenience Sampling

Using readily available participants (may introduce bias). Example: Surveying only students in your psychology class.

Generalizing

Applying research findings to a broader population. Example: Assuming a study on college students applies to all adults.

Experimental Group

The group exposed to the independent variable. Example: In a drug trial, the group receiving the actual medication.

Control Group

The group not exposed to the IV; used for comparison. Example: In a drug trial, the group receiving a placebo.

Placebo

A harmless substance with no therapeutic effect, used as a control. Example: A sugar pill given instead of real medication.

Placebo Effect

Improvement due to the expectation of receiving treatment. Example: A patient’s headache improves after taking a sugar pill they believe is aspirin.

Single-Blind Study

Participants don’t know whether they’re in the experimental or control group. Example: Patients don’t know if they’re receiving the real drug or a placebo.

Double-Blind Study

Neither participants nor researchers know who is in which group. Example: A drug trial where doctors and patients are unaware of group assignments.

Experimenter Bias

Researchers’ expectations influence results. Example: A scientist subtly hints to participants how to respond.

Social Desirability Bias

Participants answer in ways they think are socially acceptable. Example: Claiming to exercise more often than you actually do.

Qualitative Research/Measures

Non-numerical data (e.g., interviews, observations). Example: Recording emotional responses to a painting.

Structured Interviews

Interviews with predetermined questions. Example: A job interviewer asks every candidate the same questions.

Quantitative Research/Measures

Numerical data (e.g., surveys, statistics). Example: Measuring reaction times in milliseconds.

Likert Scales

A rating scale (e.g., 1–5) measuring attitudes. Example: "On a scale of 1–5, how satisfied are you with this course?"

Representation of Participants

Ensuring the sample reflects diversity (gender, race, etc.). Example: Including equal numbers of men and women in a study.

Peer Review

Experts evaluate research before publication. Example: A journal sends a study to other psychologists for feedback.

Scatterplot

A graph showing the relationship between two variables. Example: Plotting hours studied against exam scores.

Correlation Coefficient

A statistic (–1 to +1) showing the strength/direction of a correlation. Example: A coefficient of +0.8 indicates a strong positive correlation.

Effect Sizes

The magnitude of a relationship or difference. Example: A drug’s effect size shows how much it reduces symptoms.

Statistical Significance

A result unlikely due to chance (p < 0.05). Example: Finding that a new teaching method improves test scores significantly.

Directionality Problem (in Correlation)

Uncertainty about which variable causes the other. Example: Does low self-esteem cause depression, or vice versa?

Third Variable Problem (in Correlation)

An unmeasured factor may explain the correlation. Example: Ice cream sales and drownings both rise in summer (heat is the third variable).

Institutional Review Board (IRB)

A committee that ensures ethical research practices. Example: An IRB rejects a study with undue risk to participants.

Informed Consent

Participants voluntarily agree to participate after understanding risks. Example: Signing a form before joining a clinical trial.

Informed Assent

Agreement from participants who can’t give full consent (e.g., children). Example: A child nods “yes” to participate in a school study.

Protection from Harm

Researchers must minimize physical/psychological harm. Example: Stopping a study if participants show extreme stress.

Confidentiality

Keeping participants’ data private. Example: Using anonymous ID numbers instead of names.

Deception

Misleading participants, allowed only if justified. Example: Telling participants they’re testing eye contact when studying obedience.

Debriefing

Explaining the true purpose of the study afterward. Example: Revealing that a “memory test” was actually about stress responses.

Heredity

The genetic transmission of traits from parents to offspring. Example: A child inherits their mother’s eye color.

Nature

The influence of genes on behavior. Example: Twins raised apart still share similar personalities.

Nurture

The influence of environment on behavior. Example: A child learns aggression from observing violent media.

Genetic Predisposition

Increased likelihood of developing a trait due to genes. Example: A family history of alcoholism raises one’s risk.

Evolutionary Perspective

Explaining behavior as adaptations for survival. Example: Fear of snakes may be rooted in ancestral survival needs.

Natural Selection

Traits enhancing survival/reproduction become more common. Example: Birds with better camouflage avoid predators and pass on genes.

Eugenics

Controlled breeding to increase “desirable” traits (controversial). Example: Forced sterilizations in the early 20th century.

Twin Studies

Comparing identical and fraternal twins to study genetic vs. environmental influences. Example: Identical twins have higher concordance rates for schizophrenia.

Family Studies

Examining trait prevalence among relatives. Example: Studying depression rates in parents and children.

Adoption Studies

Comparing adopted children to biological/adoptive families. Example: An adopted child’s IQ correlates more with biological parents’.

Central Nervous System (Brain and Spinal Cord)

The body’s command center. Example: The brain sends signals via the spinal cord to move a hand.

Peripheral Nervous System

is that part of your nervous system that lies outside your brain and spinal cord. It plays key role in both sending information from different areas of your body back to your brain, as well as carrying out commands from your brain to various parts of your body.. Example: Sensory nerves carrying touch signals to the brain.

Autonomic Nervous System

Controls involuntary functions (e.g., heartbeat). Example: Your heart races when you’re scared.

Sympathetic Nervous System

Activates “fight-or-flight” responses. Example: Pupils dilate and adrenaline surges during stress.

Parasympathetic Nervous System

Calms the body (“rest-and-digest”). Example: Heart rate slows after a meal.

Somatic Nervous System

Controls voluntary muscle movements. Example: Lifting a cup uses motor neurons in this system.

Neurons

Nerve cells that transmit electrical and chemical signals. Example: When you touch something hot, sensory neurons send signals to your spinal cord and brain.

Glial Cells

Support cells for neurons that provide nutrients and insulation. Example: Oligodendrocytes create myelin sheaths in the central nervous system.

Reflex Arc

Neural pathway controlling reflex actions. Example: Pulling your hand away from a hot stove before feeling pain.

Sensory Neurons

Carry information from sense receptors to the CNS. Example: Optic nerves transmitting visual information to the brain.

Motor Neurons

Carry signals from CNS to muscles/glands. Example: Neurons triggering bicep contraction when lifting weights.

Interneurons

Neurons within the CNS that process information. Example: Spinal interneurons coordinating left/right leg movements while walking.

Neural Transmission

Process of electrical and chemical signaling between neurons. Example: Dopamine release in the synapse during pleasurable activities.

Action Potential

Electrical impulse traveling down an axon. Example: The 'firing' of a neuron when threshold is reached.

All-or-Nothing Principle

Neurons either fire completely or not at all. Example: A neuron firing with equal intensity whether stimulated mildly or strongly.

Depolarization

Reduction of charge difference across neuron membrane. Example: Sodium ions rushing into neuron during action potential.

Refractory Period

Brief recovery time after neuron firing. Example: The moment after flushing when a toilet won't flush again.

Resting Potential

Neuron's stable negative charge when inactive (-70mV). Example: A neuron waiting to fire is like a coiled spring ready to release.

Reuptake

Neurotransmitter reabsorption by sending neuron. Example: SSRIs block serotonin reuptake to alleviate depression.

Threshold

Minimum stimulation needed to trigger action potential. Example: Pushing a ball until it rolls down a hill.

Multiple Sclerosis

Autoimmune disease damaging myelin sheaths. Example: Patient experiencing muscle weakness and vision problems.

Myasthenia Gravis

Condition causing muscle weakness from neurotransmitter problems. Example: Drooping eyelids and difficulty swallowing.

Excitatory Neurotransmitters

Chemicals promoting neuron firing. Example: Glutamate enhancing learning and memory.

Inhibitory Neurotransmitters

Chemicals preventing neuron firing. Example: GABA reducing anxiety and promoting calmness.

Dopamine

Neurotransmitter for reward and movement. Example: Released when eating chocolate or winning a game.

Serotonin

Neurotransmitter regulating mood and sleep. Example: Low levels associated with depression.