Chapter 2 Methodology: How Social Psychologists Do Research
Social Psychology: An Empirical Science 2.1 How do researchers develop theories and hypotheses?
A Fundamental Principle • Social influence can be studied scientifically
Hindsight Bias Hindsight Bias Tendency to exaggerate prediction of an outcome after knowing that it occurred Overconfidence Bias Tendency to think we know more than we do.
Formulating Hypotheses and Theories (1 of 2) • Like other scientists, social psychologists • Develop theories • Derive hypotheses from theory • Test hypotheses • Based on the results, revise theory • Formulate and test new hypotheses
Formulating Hypotheses and Theories (2 of 2) • Previous theories and research • Science is cumulative • Dissatisfaction with behaviorism (Festinger) • Personal observation • Kitty Genovese (Latané and Darley)
The Diffusion of ResponsibilityIn October of 2011, a 2-year-old girl was struck by two vans in a row. A dozen people walked or rode past her. Why didn'tthey stop to help? Source: Kyodo/Newscom
Research Designs 2.2 What are the strengths and weaknesses of various research designs that social psychologists use?
The Observational Method • Researcher observes people and systematically records behavior. • Used to describe behavior
Researching Moods through TwitterResearchers use archival analyses to test psychological hypotheses. One study, for example, analyzed millions of Twitter messages to see how people’s moods varied over the course of a day. Source: PixelloverRM 8/Alamy
Observational Method Example • Research Question • How much aggression do children exhibit during school recesses? • Method • Behaviors concretely defined before observation • Observer systematically looks for and records behaviors • Accuracy of observer is assessed • Interjudge reliability
Interjudge Reliability Interjudge Reliability The level of agreement between two or more people who independently observe and code a set of data
Limits of the Observational Method • Certain behaviors difficult to observe • Occur rarely • In private • Archival analysis • Original may not have all information researchers need • Does not allow prediction and explanation • Limited to description
The Correlational Method • Two or more variables are systematically measured and the relation between them is assessed. Correlation Coefficient A statistical technique that assesses how well you can predict one variable from another
Positive Correlation • Increases in the value of one variable are associated with increases in the value of the other variable or as one decreases so does the other. • Aggression and viewing violent media are positively correlated • Children who are aggressive tend to watch more violent television
Negative Correlation • Increases in the value of one variable are associated with decreases in the value of the other variable • Vaccination rate correlates negatively with disease rate • More vaccinations, less disease
The Correlation Coefficient Correlation coefficients range from –1.00 to +1.00 +1.00 perfectly correlated in a positive direction 0 means that two variables are not correlated –1.00 perfectly correlated in a negative direction
Figure 2.1The Correlation CoefficientThe diagrams below show three possible correlations in a hypothetical study of watching violence on television and aggressive behavior in children. The diagram at the left shows a strong positive correlation: The more television children watched, the more aggressive they were. The diagram in the middle shows no correlation: The amount of television children watched is not related to how aggressive they were. The diagram at the right shows a strong negative correlation: The more television children watched, the less aggressive they were.
Limits of the Correlational Method • Correlation does not equal causation! • Correlational method tells us only that two variables are related • Social psychology’s goal • Identify causes of social behavior • Be able to say that A causes B, not just that A is correlated with B
Correlation Does Not Equal Causation • Three possible causal relations when a correlation is found (e.g., aggressive sexual acts and pornography) • Pornography causes viewer to become sexually aggressive • People who are sexually aggressive are more interested in pornography • Correlation is caused by something else (e.g., upbringing or subculture)
A Birth Control and STD CorrelationA study conducted in the early 1990s found a correlation between the type of birth control women used and their likelihood of getting a sexually transmitted disease (STD). Those whose partners used condoms were more likely to have an STD than were women who used other forms of birth control. Does this mean that the use of condoms caused the increase in STDs? Not necessarily—see the text for alternative explanations of this research finding. Source: Monkey Business/Fotolia
Surveys • Surveys • Representative sample of people asked about attitudes or behavior • Correlations computed using responses to questions
Surveys: Advantages and Disadvantages • Advantages • Investigate relations between variables difficult to observe • Sexual behavior & knowledge of HIV • Sample representative segments of population • Disadvantages • Accuracy of responses: • People may not know the answer—but they think they do!
The Experimental Method • The only way to determine causality is to use the experimental method. • Conditions are identical except for the independent variable (the one thought to have a causal effect on people’s responses). • Use to answer causal questions
Independent Variable (IV) • The IV is what researchers manipulate to see if it has a causal effect • (e.g., type of TV show children watch)
Dependent Variable (DV) • The DV is what researchers measure to see if it is affected • e.g., measure children’s aggression (DV) after they watch television (IV) that is either violent on nonviolent
IV and DV Example Using Latané and Darley (1970) • IV • Number of bystanders • DV • Helping behavior
Figure 2.2Independent and Dependent Variables in Experimental ResearchResearchers vary the independent variable (e.g., the number of bystanders people think are present) and observe what effect that has on the dependent variable (e.g., whether people help).
Internal Validity in Experiments • Internal Validity • Making sure that nothing besides the independent variable can affect the dependent variable • Control extraneous variables
Random Assignment • Ensure all participants have equal chance of being in any experimental condition • Ensures that differences in participants’ personalities or backgrounds are distributed evenly across conditions • most important part of the experimental method.
The Perils of Surveying a Nonrepresentative SampleFailure to Use Random Selection = Misleading ResultsIn the fall of 1936, a magazine called the Literary Digest predicted that the Republican candidate for present would win by a landslide, based on a poll they conducted. Instead, Franklin Roosevelt won every state but two, as seen in the map. What went wrong with the Literary Digest poll? Source: Franklin D. Roosevelt Presidential Library & Museum.
Limits of Experimental Method • Experimental situations can be • Artificial • Distant from real life • Tradeoff with increasing control over the situation to make it similar for all participants
External Validity in Experiments • External Validity • The extent to which the results of a study can be generalized to other situations and to other people.
Two Kinds of External Validity • Generalizability across • Situations • the extent to which we can generalize from the experimental situation to real-life situations • People • the extent to which we can generalize from the people who participated in the experiment to people in general
Generalizability Across Situations • Psychological Realism • Psychological processes triggered by experiments are similar to psychological processes in real life • Cover story • A description of the purpose of a study, given to participants, that is different from its true purpose, used to maintain psychological realism
Generalizability Across People Random selection of participants from population
Do Findings Apply to All People?Social psychologists are interested in how generalizable their findings are to different kinds of people. What are the challenges in doing so? What approaches do social psychologists take? Source: Megapress/Alamy
Improving External Validity • Field Experiments: • Experiments conducted in natural settings rather than in the laboratory • Advantages: • Participants unaware that they are in an experiment • Participants more diverse than typical college sample
Trade-Off Between Internal and External Validity (1of2) Internal validity: randomly assign to conditions and control for extraneous variables External validity: generalize to everyday life
Trade-Off Between Internal and External Validity (2of2) • “Basic dilemma of the social psychologist” (Aronson & Carlsmith, 1968) • Too much control, generalizable? • Too much like real life, control all extraneous variables? • The way to resolve this basic dilemma is not to try to do everything in a single experiment.
Tests of External and Internal Validity • Replications: • Repeating a study, often with different subject populations or in different settings • Ultimate test of external validity • Meta-analysis: • A statistical technique that averages the results of two or more studies to see if the effect of an independent variable is reliable • Test of internal validity
Basic versus Applied Research (1of2) • Basic Research • Designed to find the best answer to why people behave as they do • Conducted purely for reasons of intellectual curiosity • Applied Research • Designed to solve a particular social problem
New Frontiers in Social Psychological Research 2.3 What impact do cross-cultural studies, the evolutionary approach, and social neuroscience research have on the way in which scientists investigate social behavior?
Cross-Cultural Research Conducted with different cultures, to see if psychological processes are present in both cultures or specific to the culture in which people were raised.
The Influence of CultureSome basic psychological processes are universal, whereas others are shaped by the culture in which we live. For example, are people’s self-concepts shaped by cultural rules of how people must present themselves, such as the requirement by the Taliban regime in Afghanistan that women cover themselves from head to toe? Cross-cultural research is challenging but necessary for exploring how culture influences the basic ways in which people think about and interact with others. Source: Tom Koene/Horizons WWP/Alamy
Issues in Cross-Cultural Research • Researchers must: • Guard against imposing their own cultural viewpoints onto an unfamiliar culture • Ensure that IV & DV are understood in the same way in different cultures
The Evolutionary Approach • Evolutionary Theory • Developed by Charles Darwin to explain how animals adapt to their environments • Natural Selection • How heritable traits that promote survival in a particular environment are passed along to future generations • Organisms with those traits are more likely to produce offspring
Evolutionary Psychology • Explains social behavior in terms of genetic factors that have evolved over time according to the principles of natural selection. • Core idea: • Social behaviors prevalent today are due, in part, to adaptations to past environments • Impossible to test with experimental method