Psych & Life: Correlation Does Not Equal Causation

A correlation exists when 2 variables are related to one another in an orderly way. However, correlation does not equal causation. In other words, correlations don’t tell us whether a cause and effect relationship exists between 2 variables. For example, a child development researcher may want to investigate if the amount of time children spend in daycare is related to aggressive behavior when they enter kindergarten. A correlation between time spent in daycare and aggressive behavior will indicate if the variables are related and how strongly. It is important to note that a correlation NOT will tell the researcher whether or not time spent in daycare causes aggressive behavior.

When the results of research studies are published in the media, they are often written or discussed in a confusing and misleading manner. Articles and news broadcasts may not explicitly state whether the results of the study are based on a correlational study or an experimental study. Think about the catchy lines that the evening news uses to grab your attention (e.g., “Does walking your dog cause cancer? Find out during our 11 o’clock news show.”). However, often these news shows and articles don’t give you the details about how a study was performed so that you can make informed decisions about the results. Read the following 2 articles (i.e., "Luckiest People are born in the summer" and "Eating pizza cuts cancer risk) and examine the graph (i.e., Pirates & Global Warming). Write a 3-4 page reaction paper that addresses the following issues/questions:

1. Did the articles make it clear that correlations were used and that the results did not indicate causation? What parts of the articles made this clear? What parts of the articles did you find misleading?

2. How would you interpret the results of the graph? Why do you think that such a graph may be misleading if it was shown in a newspaper or on a morning news show?

3. What did you find interesting about these articles and graph?

4. Describe another example of correlation being confused with causation. This can be one that you create or one that you find in the media. If you find the example, be sure to tell me where you got it.

5. How can you use the information learned in this exercise?


Luckiest people 'born in summer' (

Eating pizza 'cuts cancer risk' (

Pirates and global warming