Andrew L. Geers

Goal activation, expectations, and the placebo effect.

Motivational factors receive little attention in current theories of the placebo effect. Reasons for this position are reviewed, and an argument is made for reconsidering the influence of motivation on the placebo effect. The authors hypothesize that nonconscious goals alter reactions to a placebo expectation. Specifically, the authors predict that the placebo effect is most likely to occur when individuals have a goal that can be fulfilled by confirmation of the placebo expectation. The authors tested this notion in 5 experiments. The results demonstrate the role of motivation in the placebo effect across a variety of symptom domains and via 4 different goal activation techniques. Moreover, this moderating effect occurred for both positive and negative placebo expectations, across different placebo effect measures, and in brief laboratory experiments as well as in lengthier studies. It is argued that theories regarding the placebo effect should incorporate motivational factors.

Dispositional Optimism Predicts Placebo Analgesia

UNLABELLED Based on prior research identifying dispositional optimism as a predictor of placebo responding, the present study tested the hypothesis that individuals high in optimism would be more likely to respond to a placebo analgesic. Optimists and pessimists were randomly assigned to a placebo expectation condition or a no expectation condition before a cold pressor task. Blood pressure and heart rate were recorded before and during the cold pressor task, and participant ratings of pain and expectations were obtained immediately after the task. Analysis of the expectation manipulation revealed that the placebo instruction was successful in altering participant expectancy during the cold pressor. Supporting the main hypothesis, dispositional optimism was associated with lower pain ratings in the placebo condition but not in the control condition. Because dispositional optimism can alter placebo responding to laboratory pain, future studies should examine the potential role that this individual difference factor may play in patient responsivity to pharmacological and nonpharmacological treatments for clinical pain. PERSPECTIVE This study examined the possibility that individual differences can predict placebo analgesia. Participants were randomly assigned to receive either a placebo expectation or no expectation before a cold pressor task. Dispositional optimism was related to less cold pressor pain in the placebo condition as compared with the control condition.

Expectations and Placebo Response: A Laboratory Investigation into the Role of Somatic Focus

It has been theorized that expectations are an important causal determinant of the placebo effect. Placebo expectations, however, do not always yield placebo effects. In a laboratory study, we tested the hypothesis that ones level of somatic focus moderates the effect of placebo expectations on placebo responding. We also varied whether participants were told the placebo was a drug, could either be a drug or placebo, or was a placebo. The results revealed that individuals who thought they were taking a drug (i.e., unconditional expectations) reported more placebo symptoms when they closely focused on their symptoms. Individuals told they may or may not be receiving a drug (i.e., conditional expectations) did not differ from control participants regardless of how closely they attended to their symptoms. The findings have theoretical implications for expectancy models of the placebo effect as well as for practical research comparing the type of expectations held by individuals in clinical trials and clinical practice.

Mixed-handed persons are more easily persuaded and are more gullible: Interhemispheric interaction and belief updating

Research has shown that persons with mixed hand preference (i.e., who report using their non-dominant hand for at least some manual activities) display an increased tendency to update beliefs in response to information inconsistent with those beliefs. This has been interpreted as reflecting the fact that the left hemisphere maintains our current beliefs while the right hemisphere evaluates and updates those beliefs when appropriate. Belief evaluation is thus dependent on interhemispheric interaction, and mixed-handedness is associated with increased interhemispheric interaction. In Experiment 1 mixed-handers exhibited higher levels of persuasion in a standard attitude-change paradigm, while in Experiment 2 mixed-handers exhibited higher levels of gullibility as measured by the Barnum Effect.

Dispositional optimism and engagement: the moderating influence of goal prioritization.

Research indicates that a positive relationship generally exists between dispositional optimism and goal engagement and attainment. The authors argue, however, that dispositional optimism may not always be associated with more active goal pursuit. Rather, they hypothesized that this relationship is moderated by how highly a goal is prioritized. For high-priority goals, they predicted that optimistic individuals would indeed increase goal engagement and would be more likely to attain their goal relative to individuals low in optimism. For low-priority goals, they anticipated that optimistic individuals would not display greater goal engagement or attainment. In 5 studies they assessed these predictions across a variety of domains, including friendship formation, exercise persistence, and scholastic achievement. Results supported their contention that goal priority acts as a moderator of the relationship between dispositional optimism and both goal engagement and goal attainment. Evidence of 1 mediator of this moderation effect-behavioral intentions-and of a limiting factor-the temporal ordering of goals-is also presented.

Videotaped confessions: Is guilt in the eye of the camera?

Publisher Summary It is noted that in criminal trials, fact finders that include judges and jurors make decisions based on the evaluation of the evidence presented. The kind of evidence that possibly has the greatest impact on the decision making of these trial fact finders is a defendants prior admission of guilt. The type of interrogation pressure used to induce an admission of guilt is one factor that can bias the evaluation of confession evidence. This chapter describes findings from a programmatic series of studies that demonstrate that confession evidence presented in a videotaped format, in certain instances, can introduce an undesirable bias in the evaluation of evidence by trial decision-makers. The chapter presents results from other experiments that examine the basic processing mechanisms underlying this bias and discusses the policy implications of the present research for the system of jurisprudence. The basis lies in the extensive scientific literature concerning how people go about attributing causality to the behaviors and events that they observe in their environment.

Getting to know you: Face-to-face versus online interactions

It is an open question as to how impressions formed via computer-mediated communication (CMC) differ from those formed face-to-face (FtF). Some research suggests that judgments of others formed while interacting over CMC are more favorable than judgments formed in FtF, while other researchers argue the pattern is in the opposite direction. We sought to settle this conflict by examining impressions formed via each communication mode while controlling for the other. Participants interacted with a partner twice: once FtF and once CMC. When controlling for each communication mode, participants interacting FtF, formed more positive impressions of their partner than did those in the other sequence. Furthermore, FtF participants had greater self-other agreement then those who interacted via CMC. Implications for impressions formed over the Internet are discussed.

Illusory Causation: Why It Occurs

Considerable evidence indicates that people overattribute causality to a given stimulus when it is salient or the focus of their attention—the so-called illusory-causation phenomenon. Although illusory causation has proved to be quite robust and generalizable, a compelling explanation for it has not been empirically documented. Four social-attribution studies were conducted to test the hypothesis that illusory causation occurs because salient information is initially registered, or perceptually organized, differently than nonsalient information. The results provide considerable support for the notion that peoples literal point of view affects how they initially perceive, or extract, information from an observed interaction, which in turn affects their judgments regarding the causal influence exerted by each interactant.

Discerning the role of optimism in persuasion: the valence-enhancement hypothesis.

The valence-enhancement hypothesis argues that because of their active coping strategies, optimists are especially likely to elaborate on valenced information that is of high personal relevance. The hypothesis predicts that as a result, optimists will be more persuaded by personally relevant positive messages and less persuaded by personally relevant negative messages than pessimists. It also predicts that when the message is not personally relevant, optimism and persuasion will not be related in this manner. The results of 3 studies support these predictions and supply evidence against several alternative hypotheses. The possibility that the observed effects are not due to optimism but to the confounding influence of 7 additional variables is also addressed and ruled out. Implications are discussed.

Dispositional Optimism and Thoughts of Well-Being Determine Sensitivity to an Experimental Pain Task

BackgroundPrior studies with patient samples have found dispositional optimism to be associated with less pain.PurposeWe examined the relationship between optimism and experimental pain. It was hypothesized that optimists generally cope with a painful stimulus by mentally disengaging from the pain. However, if optimists are prompted to think about health and well-being prior to the painful event, they are more responsive to the pain.MethodsOptimists and pessimists were primed with words related to health or with neutral words prior to the cold pressor task. Pain, distress, and cardiovascular reactivity to the cold pressor task were assessed.ResultsDispositional optimism was associated with lower pain sensitivity, distress, and cardiovascular reactivity in the neutral prime condition. In the health prime condition, optimists and pessimists did not differ on any of the dependent measures.ConclusionsDispositional optimism is associated with reduced pain for healthy adults encountering a brief pain stimulus. This relationship is eliminated, however, when individuals are primed with thoughts of health and well-being. The results are interpreted as evidence for the use of differential coping strategies by optimists in response to pain.