One primate study showed that, when a male monkey was experimentally caused to become the dominant monkey in his pack, his serotonin level rose, then fell when he was demoted (Raleigh et al., 1991). For humans, similar experimental data has not been available, and the relationship of serotonin to rank is not well established. However, elevated serotonin levels have been found in the leaders of college fraternities and of athletic teams.
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This paper presents a field experiment that distinguishes the tangible-benefit from the intrinsic-desire explanations for rank seeking. The subjects were students who were enrolled in a regular 4-month English course for undergraduates at a university in Hanoi, Vietnam. To investigate the behavior of rank seeking, we conducted a controlled experiment. The students were randomly divided into three groups: an unranked control group and two treatment groups. The students were tested every two weeks. Students in all three groups received their scores privately after each test. In addition, the two treatment groups were informed of their rankings, one group privately and the other group publicly. At the end of the English course, the students took the Official TOEIC Test. A positive correlation between serotonin level and social rank has also been found among male college students in general (Madsen 1994).
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4 In communication between Frank and McGuire (Frank, 1999) Both treatment groups outperformed the control group on this test. Divulging rank privately (by phone) gave the students no tangible benefits but did motivate them to increase their performance, on average from the 49.5 to the 59.5 percentile of all TOEIC-takers around the world. This impressive improvement strongly supports the hypothesis that rank motivates people even when it brings no tangible benefits.
5 Test of English for International Communication (TOEIC) is a test administered by the Educational Testing Service USA (ETS), which also administers the TOEFL. {This belongs on page 5.}
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One key feature in the design of this experiment was that subjects knew one another socially, much as we know our neighbors or colleagues. This design simulated real life. In Vietnam, students in a class generally know each other relatively well, and openly publicized grades are the standard way of informing students of their scores. This choice of venue allowed us to publicize the ranked scores of the subjects in the publicly informed treatment group.