Unit 0: Scientific Foundations of Psychology Comprehensive Study Guide

Scientific Foundations of Psychology

Definition of Psychology: Psychology is defined as the scientific study of behavior and mental processes.
The Role of Psychologists as Scientists: * Psychologists function as scientists by collecting data and making observations regarding the ways in which humans and animals behave and think. * The primary goal of these observations is to understand behavior and mental processes. * Psychologists utilize a variety of research methods and designs to conduct their scientific inquiries.
Theory Development: Research tools assist psychologists in developing psychological theories concerning behavior and mental processes.
Validity and Reliability: To ensure that results are valid (measuring what is intended) and reliable (consistent), research must adhere to strict ethical and procedural guidelines.
Historical Foundation: Historical research serves as the foundation of the field of psychology and provides the basis for the various subfields that exist today.

Principal Approaches to Psychology

Behavioral Approach: This psychological perspective is concerned with behavior reactions to stimuli and views learning as a result of experience. * Ivan Pavlov: Renowned for his work on the classical conditioning of dogs. * John Watson: Known for experiments involving classical aversive conditioning. * B.F. Skinner: Known for his experiments in operant conditioning.
Psychoanalytic/Psychodynamic Approach: This perspective is concerned with how unconscious instincts, conflicts, motives, and defenses influence human behavior. * Sigmund Freud: Referred to as the ‐Father of Psychoanalysis.‐ * Significant Figures: psychodynamic psychologists include Jung, Adler, Korney, and Kohut.
Humanistic Approach: This perspective focuses on the individual potential for growth and the role of unique perceptions in the growth toward achieving one's full potential. * Significant Figures: Carl Rogers and Abraham Maslow are the primary humanistic psychologists mentioned.
Biological Approach: This perspective is concerned with the physiological and biochemical factors that determines behavior and mental processes.
Cognitive Approach: This perspective is concerned with how we receive, store, and process information; how we think and reason; and how we use language. * Jean Piaget: Specifically studied cognitive development in children.
Evolutionary Approach: This perspective is concerned with how natural selection favored behaviors that contributed to the survival and the spread of ancestors' genes. Evolutionary psychologists utilize a Darwinian approach to study human behavior.
Sociocultural Approach: This perspective focuses on how cultural differences affect behavior.
Eclectic Approach (Biopsychosocial): The use of techniques and ideas from a variety of different approaches.
Nature of Approaches: An approach is a perspective or view involving certain assumptions (beliefs) about human behavior, including: * How humans function. * Which aspects of humans are worthy of study. * What research methods are appropriate for undertaking study.
Perspective Plurality: Several different theories can exist within a single approach, sharing common assumptions. * Psychologists generally agree that no single perspective is explicitly correct; each has strengths and weaknesses and contributes differently to the understanding of human behavior.

Research Foundations and Theories

Theories: These are defined as organized sets of concepts that explain phenomena.
Hypothesis: A prediction of how two or more factors are likely related. * Note on Proof: Proving a hypothesis is mathematically and scientifically impossible. Research aims to gather data that either supports or disproves a hypothesis rather than proving it.
Replication: The repetition of methods used in a previous experiment to determine whether the same methods will yield the same results, ensuring consistency.

Research Methods and Study Design

Research Design: The overall strategy utilized to integrate different components of a study in a coherent and logical way.
Experimental Methodology: A research design involving the manipulation of variables specifically to establish cause and effect. * Independent Variable (IV): The factor that is manipulated by the researcher; it is the hypothesized "cause." * Dependent Variable (DV): The factor that is measured to assess the effect of the Independent Variable; the behavior or mental process that is the "effect." * Random Assignment: A process where each participant has an equal chance of being placed in any group. This ensures group equivalency at the start of an experiment. * Control Group: The group that does not receive the treatment (the IV); used as a baseline for comparison. * Experimental Group: The group that receives the treatment or the manipulated Independent Variable. * Definition Requirement: For a study to be categorized as an experiment, it MUST include both a manipulated independent variable AND random assignment of participants. Without both, it is not an experiment.
Non-Experimental Methodology: Research designs that do not involve the manipulation of variables or random assignment. These can reveal associations or describe behaviors but cannot determine causality. * Case Study: An in-depth study of a single individual or a small group. While useful for rare conditions, results are typically not generalizable to the broader population. * Correlation: Measures the relationship between two variables. Crucially, correlation does not imply causation. * Meta-Analysis: A statistical analysis that combines the results of multiple studies to identify overarching patterns. * Naturalistic Observation: Observing behavior in its natural setting without any interference from the researcher.
Determining Research Design: To identify the structure of a study, ask two questions: 1. Is there manipulation of an independent variable? 2. Are participants randomly assigned to groups? * If the answer to both is yes, it is an Experimental Design. * If the answer to one or both is no, it is a Non-Experimental Design.

Procedural and Variables Detail

Operational Definition: A description of the specific procedure used to determine the presence of a variable. To operationalize is to explain exactly how a variable will be measured. * Example: Measuring "doing well" in school could be operationally defined by class rank, GPA, attendance, or assignment completion percentages.
Population: All individuals in the group to which the study applies. The population includes anyone or anything that could possibly be selected for the sample.
Sample: A subgroup of the population that participates in the study. * Goal: The sample should be representative of the larger population to allow for generalizations.
Random Selection: Choosing members of a population such that every individual has an equal chance of being chosen for the study sample. * Terminology note: When defining a random sample, one should always use the phrase, ‐a random sample of [population name].‐ * This process maximizes the chance that the sample represents the population.
Confounding Variables: Factors other than the independent variable that may cause a result. Confounds often arise due to pre-existing differences between groups before the IV is applied.

Research Controls, Reliability, and Validity

Blind Procedures: * Single-Blind Procedure: Participants do not know whether they are in the experimental or control group. * Double-Blind Procedure: Neither the experimenter nor the participants know who is in the experimental group versus the control group.
Placebo: A physical or psychological treatment given to the control group that resembles the experimental treatment but contains no active ingredient.
Placebo Effect: A response caused by the belief that the independent variable will have an effect, rather than the actual properties of the independent variable. This is considered a confounding variable.
Reliability: Refers to the consistency or repeatability of results.
Validity: The extent to which an instrument measures or predicts exactly what it is supposed to measure or predict.
Biases: * Experimenter Bias: Occurs when a researcher’s expectations or preferences about the outcome influence the obtained results. * Hindsight Bias: The tendency, after hearing about research findings, to think that one knew the outcome all along.
Demand Characteristics: Clues discovered by participants regarding the purpose of the study which suggest how they should respond.

Ethical Guidelines

Ethical Standard: Psychologists must act responsibly and morally in research and practice.
Historical Controversial Studies: * Harry Harlow: Involved rhesus monkeys separated from mothers and subjected to frightening conditions. * Phil Zimbardo (Stanford Prison Experiment): Students role-played prisoners and guards. * Stanley Milgram: Participants believed they delivered painful electric shocks to others.
APA Strengthening: Following Milgram's experiments, the American Psychological Association (APA) and other groups strengthened guidelines to prevent unnecessary deception and pain and to protect confidentiality.
Institutional Review Boards (IRBs): All public and private institutions must have an IRB to approve all research.
Human Research Requirements: * Informed Consent: Researchers must obtain signed agreements from participants. These must describe procedures, risks, benefits, and the right to withdraw or not participate without penalty at any time. * Deception Limits: Participants cannot be deceived about significant aspects that would affect their willingness to participate. * Debriefing: After completion, the nature, results, and conclusions of the research must be revealed to the participants.
Animal Research (IACUC - Institutional Animal Care and Use Committee): * Animals must be treated humanely. * Researchers must acquire, care for, and dispose of animals properly. * Efforts must be made to minimize discomfort, infection, illness, and pain.

Descriptive Statistics

Statistics: The field involving the analysis of numerical data about representative samples of populations.
Descriptive Statistics: Numbers used to summarize a set of research data obtained from a sample. * Frequency Distribution: An orderly arrangement of scores indicating the frequency of each score or group of scores.
Measures of Central Tendency: * Mode: The most frequently occurring score; described as "quick and dirty." * Median: The middle score when data is organized by size. * Mean: The arithmetic average of a set of scores.
Measures of Variability: * Range: The difference between the largest score and the smallest score; described as "quick and dirty." * Standard Deviation (SD): Measures the average difference between each individual score and the mean of the data set.
Normal Distribution: A bell-shaped curve representing how various human characteristics are dispersed in a population.
Percentile Score: Indicates the percentage of scores at or below a particular score (ranges from $1$ to $99$ ).
Correlation Coefficient (r): A statistical measure of the association or degree of relatedness between two sets of data; ranges from $-1$ to $+1$ .

Inferential Statistics and Significance

Inferential Statistics: Used to interpret data and draw conclusions.
Statistical Significance (p): * Definition: How likely it is that an obtained result occurred by chance. * Indicates a high probability that the IV caused the change in the DV. * Criteria: Results are likely significant when: 1. There is a large difference between means. 2. Standard Deviations (SD) are small. 3. Samples are large. * The p-value: * For significance to exist, $p \le .05$ . * A lower p-value indicates more significant results and less likelihood of chance causation. * A p-value of $0$ is impossible because investigators cannot be $100\%$ certain that chance is not involved.
Effect Size: A quantitative measure of the strength or magnitude of a relationship or difference. * Purpose: Indicates how much effect the IV had, regardless of sample size; helps understand practical significance. * Cohen’s d (Difference between two means): * Small effect: $\approx 0.2$ * Medium effect: $\approx 0.5$ * Large effect: $\ge 0.8$ * r or r² (Correlation coefficient / coefficient of determination): * Small effect: $\approx 0.1$ * Medium effect: $\approx 0.3$ * Large effect: $\ge 0.5$
Relationship between Significance and Effect Size: A result can be statistically significant (p < .05) but have a small effect size, meaning the result is real but may not be meaningful in the real world. Both must be evaluated to fully understand research findings.