Deception in Psychological Experiments : Two Misconceptions and a Research Agenda

(1990) traces the history of psychology’s research methodology from the nineteenth century to the emergence of modern rules of experimentation; the changes are striking. In today’s psychology laboratories, there is a strict division of labor. One is either an experimenter or a participant, but never both—at least, not in the same laboratory. Not so in Wilhelm Wundt’s laboratory at the University of Leipzig, the dedication of which in 1879 is generally recognized as the birth of modern experimental psychology. In Wundt’s laboratory, the roles of participant and experimenter were fluid, and laboratory members took on both roles. Wundt himself participated regularly as a subject in the experiments published by his students; he also contributed much of the underlying theory. That this giant himself served as a data source and rarely, if ever, as an experimenter suggests that the role of subject was thought to require greater psychological sophistication than that of experimenter. Retracing the history of one’s discipline helps demonstrate that its practices of experimentation are also a product of its times, notwithstanding often deeply entrenched beliefs to the contrary. Deception of participants is an experimental tool about which many currently harbor strong beliefs; some, for instance, deem it indispensable (e.g., Bröder 1998; Kimmel 1998). In Wundt’s laboratory, deception was impossible. Researchers at the Leipzig laboratory would function as participants, experimenters, and theorists for one another. Deception would have meant self-deception or deception of close collaborators. One does not have to travel in time, however, to realize that a discipline’s preferred practices of experimentation are relative. Sometimes glancing beyond the fence of one’s discipline suffices. In laboratories of experimental economists, the use of deception is essentially impossible because the community has effectively proscribed it (although there are rare exceptions). Economists fear that participants’ expectations of being deceived trigger suspicion and second-guessing, and that these responses swamp the impact of the experimental scenario on behavior (see Hertwig and Ortmann 2001, 2003; Ortmann and Hertwig 2002). Having established that beliefs about the rules of experimentation evolve and differ across disciplines, we discuss two widespread misconceptions about the contemporary use of deception in psychology and sketch a research agenda for the future. Before we do so, however, let us briefly clarify what is typically considered to be deception. Although deception is not easily defined, a consensus has emerged across disciplinary borders that intentional and explicit provision of erroneous information—in other words, lying—is deception, whereas withholding information about research hypotheses, the range of experimental manipulations, or the like ought not to count as deception. In the words of the economist Hey (1998:397), “there is a world of difference between not telling subjects things and telling them the wrong things. The latter is deception, the former is not” Social Psychology Quarterly 2008, Vol. 71, No. 3, 222–227