What causes mass shootings? Of course, we have no experimental evidence on this question. Correlational evidence (both within the U.S. and evidence that compares the U.S. to other countries) is consistent with the argument that gun availability is a factor.
However, this post isn't about what really causes school shootings. It's about what people think causes them. And it turns out that the race of a school shooter influences what people believe about the shooter.
After some school shootings (a subset of mass shootings), people have sometimes looked for answers not in the availability of guns, but in video games. Now, there is actually no evidence linking video games to mass shootings. However, this ABC news story talks about when people are more likely to think that video games are responsible:
There's little evidence showing a relationship between violent video games and school shootings, but video games are often blamed for overall violence in our communities. A recent study published in the Psychology of Popular Media Culture set out to find if we look for an external explanation for violence by whites more often than we do for African Americans.
"We try harder to make excuses for white perpetrators," said investigator Dr. James Ivory, a professor in the Department of Communications at Virginia Tech, in an interview with ABC News.
The first study gave people a mock news story about a school shooting. When asked what caused the shooting, people were more likely to blame video games if the shooter was white than if the shooter was black.
It turns out that in the original study (linked here; if it's paywalled you may be able to access via your university library), participants read the mock news story and were randomly assigned to one of two photos of the perpetrator--a mugshot showing either a Black or a White man.
a) There were two variables in this study. Name each one. For each, was it manipulated or measured?
b) What kind of study is this, correlational or experimental?
c) Sketch a graph of the results of this study. What will you put on the y-axis?
d) In the study above, what role does random assignment play? Why did the researchers randomly assign people to see either a Black or White perpetrator?
Here is how ABC news described the second study:
The second study looked at thousands of news articles -- video games were mentioned more often in stories of white shooters [compared to black shooters].
e) What are the variables in the study above? Name each one; for each, was it manipulated or measured?
f) What kind of study is this, correlational or experimental?
g) Sketch a graph of the results of this study.
h) In the study above, the researchers could not randomly assign news article authors to write about a black vs. a white perpetrator. How does that change the impact of this study?
i) Which of the two studies do you think provides the strongest evidence that race influences people's willingness to think video games are a cause of the shooting?
Suggested answers
a) One variable is race of the perpetrator (levels are Black or White), this was manipulated. The other variable is "likelihood to blame video games". This was measured.
b) This was an experiment because one variable was manipulated.
d) Random assignment contributes to the study's internal validity. They can be sure that the same kinds of participants were in each group (reading about Black vs. White perpetrators). Therefore, people who play a lot of video games themselves were equally likely to be in the two groups. You might be interested to know that in the original study, the researchers also pretested the Black and White photos they used to be sure that the faces differed on race but not on perceived attractiveness or dangerousness. This pretesting also contributed to the experiment's internal validity.
e) The first variable was race of the perpetrator in the article (Black or White), which was measured. The second variable was whether or not the article mentioned video games (yes or no).
f) This was a correlational study because all variables were measured.
h) Because this study used naturally-occurring crimes, the researchers may have an internal validity problem. It is possible that the Black and White perpetrated shootings differed not just on race but also on number of victims, age of victims, geography, or some other variable. This introduces an alternative explanation for the result--perhaps people blamed video games for White perpetrated shootings because they had more victims, had older victims, and so on.
i) You might have selected the first study as the strongest because it was an experiment and allows us to make a causal inference. Or you might have selected the second study because it was conducted on "real world" stimuli such as news stories--therefore it appears to have good ecological validity or external validity.
Thanks to Marianne Lloyd for this idea!