Do women tend to devalue(贬低) the worth of their work? Do they apply different standards to rewarding their own work more critically than they do to rewarding the work of others? These were the questions asked by Michigan State University psychologists Lawrence Messe and Charlene Callahan-Levy. Past experiments had shown that when women were asked to decide how much to pay themselves and other people for the same job, they paid themselves less. Following up on this finding, Messe and Callahan-Levy designed experiments to test several popular explanations of why women tend to get less in pay situations. One theory the psychologists tested was that women judge their own work more harshly than that of others. The subjects for the experiment testing this theory were men and women from the Michigan State undergraduate student body. The job the subjects were asked to perform. for pay was an opinion questionnaire(调查表) requiring a number of short essays on campus-related issues. After completing the questionnaire, some subjects were given six dollars in bills and change and were asked to decide payment for themselves. Others were given the same amount and were asked to decide payment for another subject who had also completed the questionnaire. The psychologists found that, as in earlier experiments, the women paid themselves less than the men paid themselves. They also found that the women paid themselves less than they paid other women and less than the men paid the women. The differences were substantial. The average paid to women by themselves was $ 2.97. The average paid to men by themselves was $ 4.06. The average paid to women by others was $ 4.37. In spite of the differences, the psychologists found that the men and the women in the experiment evaluated their own performances on the questionnaire about equally and better than the expected performances of others. On the basis of these findings, Messe and Callahan-Levy concluded that women's attachment of a comparatively low monetary value to their work cannot be based entirely on their judgment of their own ability. The experiment designed in the passage would be most relevant to the formulation(陈述，表述) of a theory concerning the ______.