Integrative Themes, Folders sorted by general area... sort of!

Experimentation, where the researcher is able to manipulate the independent variable and control for the influence of other possible confounding variables (i.e., other potential influences on the dependent variable), is the most reliable and powerful method for determining cause and effect. However, it is not always possible to conduct experiments in psychology (or other sciences, for that matter). Sometimes, you do not have the ability to manipulate a variable. For example, one cannot “make” someone male or female, or a particular age, etc. We can only select subjects already possessing the different attributes. We do not have the power to manipulate geographic or climatic variables to see the extent to which they influence behavior. Many variables cannot be manipulated for ethical reasons. For example, we cannot systematically punish children severely to see if that is an effective technique for eliminating undesirable behavior. Indeed, some have even questioned studying the effect of punishment on the dangerously self-destructive acts of autistic children (Bettelheim, 1985). For these reasons, many in the other laboratory sciences describe psychology as “soft.” Sometimes they even question the possibility of conducting psychology as a science. The research findings described in this book attest to the fruitfulness of applying the scientific method to psychological questions. The discipline of psychology frequently applies non-experimental designs under conditions where experimental procedures are logistically impossible, prohibitive in cost, or unethical. Frequently non-experimental studies can provide information about the relationship between variables despite not being able to demonstrate cause and effect. However, even when relationships between variables are compelling, for example when a substantial statistical correlation exists, it is still not possible to conclude cause and effect. Often there is a hidden third variable underlying the correlation. For example, it is likely there is a high correlation between the number of books in one’s home and success in school. That does not mean that by simply providing books to an individual it will improve school performance. It is likely the number of books in one’s home is indicative of a number of economic and attitudinal advantages. Still, the fact that this correlation exists is informative and could lead to an experiment to test whether there is a cause and effect relationship between the number of books and school performance.