It seems to be conventional wisdom that people are overconfident in their own abilities. People tend to think they are nicer, smarter, and better looking than most other people. But what's the evidence? The scientist-authors of this Wall Street Journal summary explain,
The claim that "most people think they are smarter than average" is a cliche of popular psychology, but the scientific evidence for it is surprisingly thin. Most research in this area has been conducted using small samples of individuals or only with high school or college students. The most recent study that polled a representative sample of American adults on the topic was published way back in 1965.
The authors, Patrick Heck and Christopher Chabris, worked with a third colleague.
..[W]e conducted two surveys: one using traditional telephone-polling methods, the other using internet research volunteers. Altogether we asked a combined representative sample of 2,821 Americans whether they agreed or disagreed with the simple statement "I am more intelligent than the average person."
Here are some of the results:
We found that more than 50% of every subgroup of people — young and old, white and nonwhite, male and female — agreed that they are smarter than average. Perhaps unsurprisingly, more men exhibited overconfidence (71% said they were smarter than average) than women (only 59% agreed).
Perhaps "overconfidence" is really accuracy? Consider this pattern of results:
In our study, confidence increased with education: 73% of people with a graduate degree agreed that they are smarter than average, compared with 71% of college graduates, 62% of people with "some college" experience and just 52% of people who never attended college.
The accessible Wall Street Journal summary is paywalled, but the original empirical publication is open-access in PLOS One.
Questions
a) What kind of study was this? Survey/poll? Correlational? Experimental? What are its key variables?
b) The authors found that more than 50% of every subgroup of people considered themselves smarter than average. Why is this result a sign of overconfidence?
c) The authors of this piece state that their combined sample was "representative". Re-read the section on how they got their sample and then make your own assessment–is the sample representative? (i.e., how is its external validity?). What population of interest do they intend to represent?
d) Sketch a graph of this result:
73% of people with a graduate degree agreed that they are smarter than average, compared with 71% of college graduates, 62% of people with "some college" experience and just 52% of people who never attended college.
e) In concluding their article, the authors wrote, "Our study shows that many people think they are smarter than they really are, but they may not be stupid to think so." What do you think? To what extent does this study's results support this conclusion?
e) Ask a question about this study's construct, internal, external, and statistical validity.