23. Maier and colleagues (2008) conducted a study to examine whether the perception of the color red can adversely affect intellectual performance. The researchers based their hypothesis on a theory that, in achievement situations, red is associated with the risk of failure, such as when teachers use red ink to correct students’

errors. To test their hypothesis, the researchers asked 20 German high school students to take a 20-item numeric IQ test and randomly assigned them to one of two experimental conditions. In one condition, a large red rectangle appeared on the cover page of the test. In the other condition, the rectangle was a gray color. The results are shown in Figure 15, which includes standard error bars. Explain what the standard error bars mean, using one of the error bars as an example, to a person who understands mean and standard deviation, but knows nothing else about statistics. (You may be interested to know that the results supported the researchers’ hypothesis: Students who viewed the red rectangle solved fewer of the IQ items than students who viewed the gray rectangle.)