Psych 315 midterm study guide 2026

Critical Period

An abrupt period of maximum sensitivity where features must develop; example includes full development of visual capabilities.

Sensitive Period

A period of heightened sensitivity to external stimuli where learning occurs, but can still be learned later less efficiently (e.g., language); cortical areas can adapt to perform different functions.

Nature

The view that heredity plays the most important role in bringing about features.

Nurture

The view that one's environment is most significant in shaping the way we develop.

Nature vs. Nurture Interaction

There is a constant interplay and deep interaction between both genes and the environment.

Systematic Empiricism

Learning based on structured observation of the natural world.

Empirical Questions

Questions about the way the world works that are answered by systematically observing it.

Public Knowledge

Publishing research after completion so scientific knowledge is self-correcting and built by many different researchers.

Quantitative Research

Research focused on providing precise, specific answers and drawing general conclusions about human behavior using statistical data; not as good at detailed descriptions or generating novel questions.

Qualitative Research

Research collecting large amounts of relatively "unfiltered" data from a small number of individuals to provide detailed, non-statistical descriptions; helps generate new hypotheses and research questions.

Mixed-Methods Research

The use of both qualitative (for generating hypotheses) and quantitative methods (for testing hypotheses).

Descriptive Studies

Studies that capture a snapshot of a current state; can report averages, tallies, or lists of responses, but cannot answer questions about relationships between variables.

Correlational Research

Research assessing relationships between two or more variables without determining cause and effect.

Positive Correlation

A relationship where two variables move in the same direction.

Negative Correlation

A relationship where two variables move in opposite directions.

Correlation vs. Causation

Correlation does NOT indicate causation; another factor (a confounding variable) may be causing systematic movement.

Confounding Variable

An outside factor that causes systematic movement in the variables of interest.

Experimental Research

Research that goes a step further by testing specific hypotheses, randomly assigning participants to conditions, and assessing the causal impact of manipulations on a dependent variable.

Observational Research

Watching and recording specific behaviors of participants.

Hawthorne Effect

Changes in participants' behavior caused by the awareness that they are being observed.

Surveys

Data collection tool that enhances accessibility to subjects quickly, but can limit accuracy.

Content Analysis

Analyzing media (such as pictures, lyrics, or old texts) or examining documents to uncover attitudes, practices, or preferences.

Secondary Data Analysis

Analyzing information that has already been collected by someone else.

Reliability

The ability of a test or instrument to produce consistent and reproducible results in a given way.

Validity

The extent to which a given instrument or tool accurately measures what it is supposed to measure.

p-value

The probability showing how much random variation can be expected in results; typically p<0.05 indicates statistical significance.

Illusory Correlation

When people believe that a relationship exists between two things when no such relationship exists (e.g., moon phases affecting human behavior).

Confirmation Bias

Ignoring evidence that would show our hunch or hypothesis is false.

Experimental Group

The group in an experiment that receives the experimental manipulation or treatment variable being tested.

Operational Definition

A precise, clear description of how variables will be measured in a study.

Experimenter Bias

The possibility that a researcher's expectations influence the outcomes of a study.

Single-Blind Study

A study design where participants are unaware of which group assignment they are in.

Double-Blind Study

A study design where both the researchers and the participants are unaware of group assignments.

Placebo Effect

When people's expectations or beliefs influence or determine their experience in a given situation (e.g., taking a pill).

Dependent Variable

The variable being measured, which depends on changes in the independent variable.

Independent Variable

The variable that is manipulated by the experimenter.

Random Sample

A subset of a larger population in which every member has an equal chance of being selected.

Quasi-Experiments

Experiments used when true experiments cannot be conducted due to ethical constraints; cannot make direct cause-and-effect claims.

Statistical Analysis

Analysis conducted to determine if meaningful differences exist between groups and how likely those differences are due to chance.

Cross-Sectional Research

Design used to examine behavior in participants of different ages who are tested at the same point in time (yields info about age differences, not changes over time).

Longitudinal Research

Design that examines changes within the same individuals over time; provides true developmental analysis, but is expensive, time-consuming, and prone to participant drop-out.

Sequential Research

Design combining cross-sectional and longitudinal approaches; examines changes within individuals over time AND across different age groups at the same point in time.

Cohort Effects

Differences between groups attributable to their shared era, generation, or historical background.

Institutional Review Board (IRB)

A committee that must review and approve all research projects before they are conducted.

Informed Consent

Formal permission signed by participants before being studied (for minors, it is called assent).

Assent

Agreement given by minors to participate in a study alongside parental consent.

Attrition

Participant drop-out rates in studies (typically higher in studies with infants than adults).

Scientific Method

An objective, systematic, and testable approach that always begins with an observation.

Research Foundations

Broad research ideas often stem from personal experiences, social problems, or testing known theories.

Evaluating Research Claims

The step-by-step process of evaluating research: 1) Look at the claim, 2) Research the question, 3) Search for data/methods, and 4) Evaluate the sample, measures, and limitations.

Study Limitations

The principle that every study contains limitations that must be acknowledged.

Objectivity in Research

Maintaining complete neutrality and avoiding biased claims or unverified assumptions when analyzing data.

3rd Variable Problem

Occurs when a confounding variable (such as gender) influences the relationship between two variables being studied.

Correlation vs. Causation

Just because two things are related or sound logical does not mean one causes the other.

APA Ethical Guidelines

Standards for conducting research ethically, requiring informed consent, assent for minors, confidentiality for sensitive topics, debriefing, and avoiding deception or harm.

Informed Consent

Formal permission obtained from adult participants prior to participating in research.

Assent

Permission given by minors to participate in research in addition to parental consent.

Debriefing

The ethical practice of being fully transparent with participants after a study is completed.

Confidentiality

Protecting participant privacy, especially when asking sensitive questions.

Positionality

Acknowledging one's own social, political, and personal standing to minimize racial, ethnic, cultural, sex, and gender identity biases.

Qualitative Data Collection Methods

Methods used to collect rich, non-statistical data, including interviews, focus groups, open-ended survey responses, and detailed observational notes.

Research Question Requirements

To be research-ready, a question must define: 1) Who or what will be studied (population), 2) What can be observed or measured, and 3) What relationship is being investigated ethically.

Mediator

A variable that explains the mechanism or process through which an independent variable influences a dependent variable.

Moderator

A variable that changes or influences the strength or direction of the relationship between an independent variable and a dependent variable.

Reading Correlation Tables

Asterisks (*) in a table indicate a statistically significant relationship between variables.

Positive Relationship Example

A correlation of +0.41 between risk-taking and perceived stress indicates a moderate positive relationship where lower risk-taking is associated with lower perceived stress.

Regression Table (b weight)

In a regression table, b represents how much the dependent variable increases or decreases for every 1-unit increase in the independent variable.

Glial Cells

Brain cells that play a supportive physical and metabolic role to neurons.

Neurons

Interconnected information processors essential for all tasks in the nervous system.

Synapses

The intersections where the axon of one neuron reaches toward the dendrites of receiving neurons without directly touching.

Neurotransmitters

Chemical messengers released by electrical impulses in axons that carry information across synapses to receiving dendrites.

Synaptogenesis

The process of forming new connections between neurons.

Synaptic Pruning

The reduction and refinement of neural pathways, making connections and brain function more efficient for mastery of skills.

Excessive or Deficient Pruning

Too much synaptic pruning is linked to schizophrenia, while too little synaptic pruning is associated with epilepsy and autism.

Myelin

A protective coating that insulates nerve cells, speeding the rate of signal transmission and improving movement coordination and control.

Neuroplasticity

The brain's ability to physically and chemically change, allowing it to adapt to new experiences and store memories.

Cortex

The thin outer covering of the brain involved in voluntary activity and high-level thinking.

Frontal Lobe

Region of the cortex responsible for thinking, planning, memory, and judgment.

Parietal Lobe

Region of the cortex located from the middle to back of the skull that processes touch information.

Occipital Lobe

Region at the very back of the skull responsible for processing visual information.

Temporal Lobe

Region located between the ears that handles hearing and language processing.

Lateralization

The process by which specific brain functions become localized primarily on one side or hemisphere.

Corpus Callosum

Structure that connects and allows communication between the left and right hemispheres.

Prefrontal Cortex

The "CEO" of the brain, involved in decision-making and cognitive control; undergoes myelination and pruning in a back-to-front pattern into early adulthood.

Limbic System

Brain system that processes emotional and social information, rewards, and punishments; targeted by pubertal hormones during adolescence.

Adolescent Sleep & Melatonin

Blood melatonin levels rise later at night and fall later in the morning during adolescence, making teens stay up late and struggle to wake up early.

Adolescent Risk-Taking

Caused by early maturation of the reward-sensitive limbic system paired with prolonged, slower maturation of the prefrontal cortex.

Dopamine & Sensation-Seeking

Increased dopamine release during sensation-seeking behavior heightens reward sensitivity in teens (higher in males aged 14–22).

Early vs. Late-Start Antisocial Behavior

Distinguishes individuals whose antisocial behavior begins during childhood (early-start, carrying higher risk for long-term antisocial behavior) versus later.

Brain Cell Volume vs. Refinement

The brain does not continuously create new cells; instead, it refines neural activity, myelination, and pruning over time.

White Matter Trajectory

White matter volume increases with age as myelination strengthens connections between brain regions.

Peak Brain Optimization

Brain circuits refine and become most organized around 30 years of age.

Puberty Trigger

Puberty begins in the brain (the hypothalamus), which signals the pituitary gland to release FSH and LH hormones to the gonads.

Gray Matter Trajectory

Gray matter volume peaks early in development and decreases over time as the brain prunes unused connections.

Estrogens vs. Androgens

Estrogens (such as estradiol) are female sex hormones produced by ovaries, while Androgens (such as testosterone) are male sex hormones produced by testes.

Structural Brain Maturation Pattern

The brain structurally matures in a back-to-front pattern, with the prefrontal cortex maturing last.

Limbic Remodeling in Puberty

Puberty remodels the limbic system, driving desires for novel experiences, autonomy, and peer connection while defaulting to raw impulses.

Dopamine Spike in Adolescence

Puberty triggers a non-linear spike in dopamine receptors in the brain's reward system.

Hot vs. Cold Cognition

Adolescents process risks and higher-level decisions well in solo or low-emotion settings ("cold"), but struggle more in social or peer-present settings ("hot").

ABCD Study

A research study evaluating how adolescent brains change and how these changes influence behaviors and decision-making.