Unit 02

How do Psychologists Conduct Scientific Research on Evil?

Every single person who has, or will ever read this page has their own assumptions, opinions, biases, and beliefs about themselves and other people... but if we actually want to know something about evil, we have to carefully design research studies to test our ideas with observable evidence.  Before we can get too far into the science of evil, let's clarify how we go about designing valid research on affect, behavior, and cognition.

02-A: Pseudoscience, Science, or Common Sense?

• What are some examples of how early psychologists failed to support their assumptions with legitimate research?

• What are the core principles of modern psychological science?

READ: Psychology as a Science - From the top of the page, including the sections titled The Key Features of a Science and The Scientific Process, then stop when you reach the Psychological Approaches and Science section.

02-C: Methods for Collecting Data

• How do researchers use different methods and designs to test their hypotheses? Be prepared to give a few original examples of how you would use each method to collect data.

  • • Measurement methods 

      • • Naturalistic observation

        • Structured observation

        • Self-report

        • Psychophysiological

        • Archival

    • Measurement timelines 

      • • Longitudinal study

        • Cross-sectional study

    • Study designs 

      • • Case study

        • Correlational

        • Controlled experiment

• What are some advantages and disadvantages of each method/design?

READ: "Methods for Collecting Data". 

Imagine that you have been hired to determine whether mindfulness meditation is effective in reducing rage among those who have been convicted of a minor, anger-fueled crime. Having mastered psychological research methods, you know that you'll need to randomly assign the participants into two groups -- one that completes the class and another that does not. You also know that you'll need to measure their rage afterwards to see if there are any noticeable difference between the two groups.

Conceptual variables are the ideas we are interested in studying. In this case we have an intervention to randomly assign (our conceptual IV) and rage to measure (our conceptual DV). In order to actually conduct the study, of course, we have to define exactly what the intervention will involve and exactly how we are going to measure rage afterwards.

First, we need an operational definition of mindfulness meditation... which meditation will they complete? For how long, and how often? Will they do it by themselves using their cellphones, go somewhere and do it as a group? We will operationalize the IV by giving a precise definition for what does and does not count as a valid form of our conceptual variable. Listening to 30 minutes of classical music three times a day might be a reasonable operationalization for relaxing, but it wouldn't work for mindfulness meditation.

Next, we need to operationalize our DV. Do we give them a survey and ask how angry they've been feeling recently? Do we follow them around and look for specific behaviors like yelling (speaking to someone at 60 decibels or louder)? Do we have them come into a lab and intentionally frustrate them with a broken pencil and count the number of swear words they use? There are often many different ways we can operationalize the conceptual variable we're interested in, and each may have different pros and cons. The thing to keep in mind is that you want to be very precise with what you're counting or measuring so that other people looking at the same situation would come to the same measurement. If you're counting swears, which words count?

In summary, conceptual variables are the ideas we talk about and operationalizations are what we manipulate and measure in a study.

02-E: Research Bias and Errors

• What are some of the most common ways that mistakes in research methodology can introduce errors and biases into the data? Describe each of the following biases and how researchers can avoid them:

  • • Demand Characteristics

    • Placebo Effect

    • Rosenthal Effect

    • Social Desirability

READ: Research Bias and Errors. 

02-F: Correlation Does Not Imply Causation

• What does it mean to say that two variables are correlated?

  • • How can you describe positive, negative, & curvilinear correlations?

    • How is the strength of that correlation expressed numerically?

• Describe the nature of correlational research designs

  • • Limitations of what we can conclude from correlations

    • Spurious correlations

• Why do we have to be so careful about how we interpret correlations?

READ: Correlation Does Not Imply Causation

02-G: What Makes a Research Study a True Experiment?

• How do we differentiate between the independent and dependent variables?

• What does it mean to randomly assign participants to experimental conditions?

• Why is random assignment essential if we want to conclude that it was our manipulation of the IV that caused differences in the DV?

• Referring back to the article in the previous section, what are some variables that could not (or would not) be manipulated or randomly assigned? How would we study them with a correlational design?

READ: What Makes a True Experiment?

Closing Thoughts...

No matter how true something seems based on personal experience, it might not actually be true.  If we want to understand the world (rather than our biased intuition about it) we have to use a careful, objective process to observe it.  The more you know about this process the better prepared you are to differentiate an opinion from a scientific fact.

If you're interested in learning more...

READ: Correlational designed studies determine a relationship between two variables. As it turns out, seemingly unrelated variables can be correlated with one another. If you want to see some more (and pretty amusing) examples of spurious correlations explore the linked website. 

READ: If you are interested in learning more about the American Psychological Association's ethical principles you can find them here.