L89The learned are humble, and the ignorant are arrogant. Darwin wrote in “The Descent of Man”: “Ignorance more frequently begets confidence than does knowledge.” (Ignorance more frequently begets confidence than does knowledge.) In 1999, this old hypothesis was tested experimentally.
Kruger and Dunning were inspired by a “smart and stupid thief” story. In 1995, a robber named McArthur Wheeler robbed two banks in Pittsburgh, Pennsylvania, in broad daylight and without a mask. The case was quickly solved within hours. “I had lemon juice on it,” Wheeler told police, astonished. Apparently, he thought the lemon juice would make him invisible to the camera. Kruger and Dunning hypothesized that people with low levels of ability face a double problem: on the one hand, they are prone to making bad decisions, and on the other hand, their low ability prevents them from correctly recognizing their own inadequacy. They designed 4 studies to test this hypothesis.
In the first study, they recruited 65 college students to answer a questionnaire that listed 30 jokes. The respondents were asked to rate the funnyness of each joke to test their humor evaluation ability. The researchers then emailed eight professional comedians to provide “professional” opinions on the funnyness. The researchers compared the above two scores to obtain the ranking of the students’ humor appreciation ability (calculated in percentiles). At the same time, the students also had to estimate their own rankings.
The results of Study 1 showed that the subjects generally overestimated their own humor appreciation ability, that is, the estimated ranking was higher than the actual one. However, the degree of overestimation was higher among the lower-ability (lower-ranked) classmates. Among the bottom 25% of classmates, the ranks were overestimated by an average of 46%.
The second study instead measured logical ability, which can present a more objective ability score. A total of 44 students completed the test. After answering 20 logical thinking questions, subjects were asked to estimate their rank on the test and estimate the number of questions they answered correctly on the test. The result is similar to the first study, people with lower abilities tend to overestimate their abilities.
As the research didn’t end there, Kruger and Dunning devised a third study, this time measuring the subjects’ English grammar skills. In Study 3, in addition to comparing the differences between the subjects’ self-assessment and substantive abilities, the two groups of students with higher and lower scores were asked to come back for the second part of the study. In the second part of the research, students had to score the tests of other students, assess the ability level of other students, and then re-evaluate their own ability. Level to self-reflection.
The results of Study 3 showed that the subjects in the low-ability group failed to adjust their rankings by checking the test papers of other students (statistically not significant), whereas the subjects in the high-ability group, whether learning Ability rankings and test scores both have significant self-upgrades, narrowing the cognitive gap.
Readers may question that people with low abilities may have a greater chance of overestimating themselves because of their lower scores. Kruger and Dunning also admitted that the first three studies could not rule out this possibility, and called it “regression effect” (Regression effect). Therefore, the last piece of the research puzzle is to explore whether the training courses can improve the subjects’ metacognitive skills (Metacognitive skills), that is, to strengthen the subjects’ thinking about their own cognitive abilities, especially for those with low abilities.
Kruger and Dunning first arranged 140 college students to take a logical reasoning test, and then randomly selected 70 subjects to receive relevant short-term logic training courses, and the other 70 subjects received unrelated courses of the same learning time. Finally, they had to re-examine the tests they had taken before the training, estimate the number of questions they answered correctly and rank, and compare them with previous estimates. Results In both groups of subjects, there was a statistically significant improvement in the performance of the retested items, but the range in the trained group was significantly greater. However, only the trained group showed a significant improvement in the rankings for estimating their abilities.
It took so much effort to prove that the more ignorant people are, the easier it is to overestimate themselves. Psychology calls it the “Dunning–Kruger effect”. Dullimp’s opponents used this effect to explain what Dullimple did. If there is such a person around you, you should also let him know about it.