Chapter 2: Asking and answering research questions (pp. 25–55)
What's it about?
Social psychologists strive to reach general conclusions by developing scientific theories about why people behave the way they do, both to solve large social problems as well as to understand everyday events. These scientific theories must satisfy three requirements: (1) they are about constructs, (2) they describe causal relationships, and (3) they are general in scope.
In order to test their theories, social psychologists must design research that is valid, according to three types of validity. Construct validity, which means the extent to which independent and dependent variables actually measure the intended theoretical construct, is often threatened by the social desirability response bias, when people act in ways that they think are socially desirable. Internal validity ensures that changes in the independent variable actually caused the changes in the dependent variable.
Nonexperimental research designs often lack internal validity because the variables are merely measured (not manipulated); however, experimental research designs using random assignment of participants to groups and manipulations of variables, have high internal validity. External validity, which means that results can be generalized across other setting, populations, and times, is ensured by conducting replications of studies.
When conducting scientific research, it is crucial for researchers to treat participants fairly, either by obtaining their informed consent before the experiment; or, if deception is used, by debriefing participants after the experiment on the purpose of the study, and the reasons for the deception. Although social psychologists cannot provide answers to moral and ethical questions, scientific research can help inform society on the relevant topics of those questions.