Experimental Demand Characteristics Research Articles

Sensitivity to financial rewards and impression management links to smartphone use and dependence

Computational modeling and brain imaging studies suggest that sensitivity to rewards and behaviorist learning principles partly explain smartphone engagement patterns and potentially smartphone dependence. Responses to a questionnaire, and observational measures of smartphone use were recorded for 121 university students. Each participant was also tested with a laboratory task of reward sensitivity and a test of verbal operant conditioning. Twenty-three percent of the sample had probable smartphone addiction. Using multivariate regression, smartphone use, particularly the number of instant messenger services employed, was shown to be significantly and independently predicted by reward sensitivity (a positive relationship), and by instrumental conditioning (a negative relationship). However, the latter association was driven by a subset of participants who developed declarative knowledge of the response-reinforcer contingency. This suggests a process of impression management driven by experimental demand characteristics, producing goal-directed instrumental behavior not habit-based learning. No other measures of smartphone use, including the self-report scale, were significantly associated with the experimental tasks. We conclude that stronger engagement with smartphones, in particular instant messenger services, may be linked to people being more sensitive to rewarding stimuli, suggestive of a motivational or learning mechanism. We propose that this mechanism could underly problem smartphone use and dependence. It also potentially explains why some aspects of smartphone use, such as habitual actions, appear to be poorly measured by technology-use questionnaires. A serendipitous secondary finding confirmed that smartphone use reflected active self-presentation. Our ‘conditioning’ task-induced this behavior in the laboratory and could be used in social-cognition experimental studies.

Not by strength alone : children's conflict expectations follow the logic of the asymmetric war of attrition.

The Asymmetric War of Attrition (AWA) model of animal conflict in evolutionary biology (Maynard Smith and Parker in Nature, 246, 15-18, 1976) suggests that an organism's decision to withdraw from a conflict is the result of adaptations designed to integrate the expected value of winning, discounted by the expected costs that would be incurred by continuing to compete, via sensitivity to proximate cues of how quickly each side can impose costs on the other (Resource Holding Potential), and how much each side will gain by winning. The current studies examine whether human conflict expectations follow the formalized logic of this model. Children aged 6-8years were presented with third-party conflict vignettes and were then asked to predict the likely winner. Cues of ownership, hunger, size, strength, and alliance strength were systematically varied across conditions. Results demonstrate that children's expectations followed the logic of the AWA model, even in complex situations featuring multiple, competing cues, such that the actual relative costs and benefits that would accrue during such a conflict were reflected in children's expectations. Control conditions show that these modifications to conflict expectations could not have resulted from more general experimental artifacts or demand characteristics. To test the selectivity of these effects to conflict, expectations of search effort were also assessed. As predicted, they yielded a different pattern of results. These studies represent one of the first experimental tests of the AWA model in humans and suggest that future research on the psychology of ownership, conflict, and value may be aided by formalized models from evolutionary biology.

Who is being deceived? The experimental demands of wearing a backpack

A growing literature argues that wearing a heavy backpack makes slopes look steeper and distances seem longer (e.g., Proffitt, 2006). To test for effects of experimental demand characteristics in a backpack experiment, we manipulated the experimental demand of the backpack and then used a postexperiment questionnaire to assess participants' beliefs about the purpose of the backpack. For participants in the low-demand condition, an elaborate deception was used to provide an alternative explanation of the requirement to wear a heavy backpack (i.e., that it held EMG equipment). The highest slope judgments were found for those undeceived participants who guessed that the backpack was intended to affect their slope perception and also reported that they thought they were affected by it. When persuaded that the backpack served another purpose, participants' slope estimates were no different from those of participants not wearing a backpack. These findings suggest that backpack effects, and other reported effects of effort on perception, are judgmental biases that result from the social, not physical, demands of the experimental context.

Attenuation and Enhancement of Compliance with Experimental Demand Characteristics

College students chose between reinforcement schedules in which a key press produced a cartoon video followed by nonreinforcement. The experimenter introduced a demand characteristic by stating a preference for choosing one schedule while indicating that the other schedule was also acceptable. With identical schedules (25 s of reinforcement, 5 s of nonreinforcement), compliant choices approached 100%. When the designated schedule presented a 5-s reinforcer followed by a 25-s timeout, participants complied initially, and then chose the other schedule on most trials. The aversiveness of the timeout, combined with the predominantly reinforcing alternative, deterred compliance. Elaborating the instructional context by stating that choosing the designated schedule would “help us with the data analysis” significantly increased compliant choices but did not alter the rise-and-decline pattern found with the simpler instructions. A salient relation between an experimenter’s preference and a scientific benefit thus promotes compliance with demand cues but does not insulate it from attenuation by relatively mild aversive consequences. Demand characteristics are not a uniquely powerful source of behavioral control.

Suggestibility and state anxiety: How the two concepts relate in a source identification paradigm

Source identification tests provide a stringent method for testing the suggestibility of memory because they reduce response bias and experimental demand characteristics. Using the techniques and materials of Maria Zaragoza and her colleagues, we investigated how state anxiety affects the ability of undergraduates to identify correctly the source of misleading post-event information. The results showed that individuals high in state anxiety were less likely to make source misattributions of misleading information, indicating lower levels of suggestibility. This effect was strengthened when forgotten or non-recognised misleading items (for which a source identification task is not possible) were excluded from the analysis. Confidence in the correct attribution of misleading post-event information to its source was significantly less than confidence in source misattributions. Participants who were high in state anxiety tended to be less confident than those lower in state anxiety when they correctly identified the source of both misleading post-event information and non-misled items. The implications of these findings are discussed, drawing on the literature on anxiety and cognition as well as suggestibility.

Other: The unsung variable: Experimenter characteristics in human pain research

Experimenters are inextricable aspects of pain research. State-of-the-art clinical trials in the field of pain employ “double blind” methodology to minimize the influence of experimental demand characteristics and placebo effects on outcome. At an even more basic level, effects of the “mere presence” of an experimenter have been shown to impact subject reports pain research (e.g., Craig et al., 1974). Human research articles in Volume 99 of the International Association for the Study of Pain's journal “Pain” were reviewed. Brief notes, reviews, commentaries, editorials, responses and studies in which participants had no contact with experimenters (e.g., Internet-based experiments) were excluded. The primary investigator and one trained investigator manually reviewed articles and electronically searched using key words (e.g., experimenter, investigator, researcher, assistant, technician, interviewer). Information was recorded about the number of experimenters and their role in the social context of experiment (e.g., verbally administered pain measures versus provision of paper and pencil measures to participants). While 100% of studies reported participant characteristics (e.g., gender, ethnicity) and sample size, only 52% alluded to or indicated anything about the persons who collected data. Four studies out of twenty-three (17%) reported the number of experimenters utilized, and only one study (4%) described any experimenter characteristics (e.g., number of years experience) other than occupation (e.g., nurse). Seven (30%) of the studies reported information related to the experimenter's role in the social context in which pain measures were obtained. Given research evidence that experimenter factors can impact ratings provided by subjects in pain research, those variables should be routinely listed in published reports of pain research that uses human subjects. However, this review indicates that experimenter variables are rarely described. More emphasis needs to be directed towards consideration of the interpersonal and sociocontextual variables that might be operating in human pain research.

Experimental and Psychotherapeutic Demand Characteristics and the Cognitive Therapy Rationale: An Analogue Study

In cognitive therapy (CT) for depression, the treatment rationale is presented in lay terms as an ABC sequence such that A represents a recent event, B represents automatic thoughts about the event, and C represents the resulting affective response. The role of demand characteristics in rationales such as this has been extensively explored in research on systematic desensitization but little has been done with regards to CT. This study investigated the influence of the CT rationale and an alternative rationale on participants' self-reported thoughts and feelings in response to images. While the CT rationale assumes that cognition precedes and causes affect, the alternative rationale flipped the terms of ABC into an ACB theory in which affect is assumed to precede and cause cognition. We found that both rationales influenced reporting: Those who received the ABC rationale reported that more automatic thoughts were evoked first, while those who received the ACB rationale reported that more automatic feelings were evoked first. The rationales also were more influential on high arousal images and less influential for participants with previous therapy experience. Results are discussed in terms of experimental demand characteristics (conscious compliance) and psychotherapeutic demand characteristics (nonconscious changes in clinically relevant behavior) and implications for therapy.

Psychophysically determined work durations for limiting shoulder girdle fatigue from elevated manual work

An early symptom of many soft tissue disorders is excessive muscle fatigue during manual work. This study adopted a psychophysical approach to determine work durations for limiting shoulder-girdle fatigue. In a series of four experiments, each subject monitored his/her level of arm/shoulder discomfort while performing a task requiring repetitive, elevated arm movements. Over the course of a short (3–6 hr) work day, the subject terminated each trial, initiating a 1-min rest period, when the discomfort reached a pre-specified level on Borg's 10-point category-ratio scale. Average trial durations decreased minimally or remained stable over the work day. Nevertheless, increases in task loading variables, including repetition rate, required force, tool weight and reach height, each led to significant decreases in work duration. (Average trial durations associated with varying levels of work demand ranged from 29 to 160 sec.) Rate and force of movement had the largest effects on work duration. The effects of reach height and tool weight were small by comparison. Thus, the former two factors are relatively more crucial in the development of shoulder and arm fatigue. Unexpectedly, males tended to engage in longer work trials than females, despite controlling for upper body strength. The possible role of gender-related experimental demand characteristics is discussed.

Effects of Experimental Context, Demand Characteristics, and Situational Cues: New Data

When in 1964 stress induced by Restricted Environmental Stimulation (REST) was publicized, Orne and Scheibe showed "sensory deprivation" effects could be produced merely by manipulating contextual cues. Since REST is now widely regarded as beneficial, it seemed appropriate to reexamine these early findings. Stringently replicating Orne and Scheibe's procedures, 10 subjects were exposed to conditions designed to generate expected REST effects. Conditions for 10 controls suggested that nothing was expected to happen. Analyses did not confirm earlier findings as no significant difference was found between experimental and control groups on any measure. A postexperimental inquiry identified positive attitudes toward REST. The specific experimental context, demand characteristics, and situational cues did not elicit responses inconsistent with the general sociopsychological context. Researchers are cautioned about attributing causality to contextual cues because context exists merely at a correlative level with data collection.

Color affects perceived odor intensity.

In Experiment 1, some odorous solutions (e.g., strawberry) were rated as smelling stronger when colored (e.g., red) than when colorless. Experiment 2 showed this effect to be due to a perceptual change rather than a response to experimental demand characteristics. Experiment 3 showed that the color-induced increase in odor intensity is not due to subjects' preexperimental experience with particular color-odor combinations, because the increase occurred with novel ones. We conclude that color induces a weak olfactory percept that combines with odorant-induced percepts. The effect may be due to conditioning or may be the result of residual intersensory neural connections left over from infancy.

Self-evaluations following performance on interpersonal tasks by depressed and nondepressed students

Mildly depressed students and nondepressed controls engaged in a series of interpersonal tasks and rated their own performance after each task. Half of each group worked on the tasks and did the self-rating in a “public” condition (experimenter present), whereas the other half of ech group were in a “private-anonymous” condition (experimenter absent). The results indicated that depressed subjects in the public condition evaluated their performance as significantly lower than depressed subjects in the private condition. The latter group's self-ratings were not significantly different from those of nondepressed subjects. The results were discussed in relation to experimental demand characteristics and depression theory.

The cognitive model of depression and mood-induction procedures: A reply to Clark (1983)

In a recent article on mood-induction procedures, Clark (1983) concluded that the Velten Mood Induction Procedure (VMIP; Velten, 1968) produces a good analog state of mild, naturally occurring, retarded depression that is not explicable in terms of experimental demand characteristics. Clark concluded, however, that it is erroneous to view the relative success of the VMIP in simulating the effects of depression as support for cognitive theories of depression. While we agree with the first of Clark's conclusions, we disagree with his second conclusion that the VMIP is not a cognitive manipulation. The purpose of the present article is to argue that his ideas regarding the impact of the VMIP on mood and behavior are not supported by the existing data. Therefore, the VMIP results can be used to support Beck's (1976) cognitive theory of depression.

The Place of the Human Subject in the Operant Laboratory

Although laboratory study of human behavior seems an obvious vehicle for strengthening the scientific base of behavior analysis, the place of the human subject within the operant laboratory remains problematic. The prevailing research strategy has been to link principles developed with animals to human affairs, either through interpretation of naturally occurring human behaviors or through application of the principles to the solution of human problems. The paucity of laboratory research on human operant behavior derives from several misconceptions: the possibility that experimental demand characteristics and pre-experimental behavioral dispositions of human subjects contaminate the results; that ethical considerations place undue constraint on research topics and experimental designs; and that uncontrollable variation in subjects' histories and other relevant personal characteristics prevents observation of reliable functional relations. We argue that these problems do not pose insurmountable obstacles to the experimental analysis of human behavior; that adequate methods of control and analysis are available; and that operant techniques, by emphasizing experimentally imposed contingencies, are well suited for the laboratory study of human behavior.

Restricted environmental stimulation and the enhancement of hypnotizability: pain, EEG alpha, skin conductance and temperature responses.

Abstract Restricted environmental stimulation procedures were used with 10 Ss. The Stanford Hypnotic Clinical Scale: Adult (SHCS) of Morgan and J. R. Hilgard (1975), modified to include a posthypnotic suggestion for an analgesic reaction, and pain threshold and tolerance tests were administered prior to restricted environmental stimulation technique (REST), immediately after REST, and 10–14 days later. Occipital EEG alpha, skin conductance, and peripheral, core, and chamber temperature data were collected prior to, during, and after REST. A control group of 10 Ss was used to assess the effects of repeated hypnosis upon susceptibility scores and demand characteristics of the experiment. Multivariate analysis of variance results showed SHCS and pain tolerance scores to be significantly enhanced for Ss exposed to REST immediately after and 10–14 days later. Orne's (1959) postexperimental inquiry technique did not reveal experimental demand characteristics which might account for the results. EEG alpha densit...

Mental travel: some reservations.

Two experiments were conducted to assess the extent of potential experimental demand characteristics inherent in the image-scanning paradigm. The results of the first "mental travel" experiment that pitted verbal versus imagery coding showed that (a) the positive correlation between physical distance and reaction time was replicated, and (b) when given a choice, subjects' reaction times varied as a function of verbal codes rather than imagery. To isolate the effects due to demand constraints from those produced by mode dominance, a nonexperiment in which subjects received only a description of the image-scanning procedure was conducted. Results demonstrated that subjects were capable of predicting the reaction time results for both verbal and imagery codes. The presence of experimental demand in the image-scanning paradigm necessitates caution when structural interpretations of visual images are considered.

Solomon Design Analysis of Multiple-Choice Rorschach Animal Content

The Solomon four-group design was used to study the effects of a persuasive message on a selected multiple-choice Rorschach index--animal content. The independent variable elicited behavior in a predictable manner. Pretesting as a main effect was not significant, but as an interactional effect obviated the effect of the persuasive message. Although knowledge of test rationale can elicit behavior that conforms to experimental demand characteristics, some subjects nonetheless acted in defiance of such information. A condition for defiance in this experimental arrangement, however, was pretesting. Other possibilities regarding the study of compliance behavior and the use of pathognomonic indicators were suggested. Ethical issues were raised.

Electrical aversion therapy with alcoholics: An analogue study

Chronic alcoholic patients matched on age, education and length of problem drinking were assigned to one of three treatment conditions, with 10 subjects in each group: (1) Electrical Aversion Conditioning (high shock paired with alcohol sips); (2) Control Conditioning (very low shock paired with alcohol sips); and (3) Group Therapy (confrontation psychotherapy). Groups 2 and 3 were included to control for possible ‘attention-placebo’ and expectancy factors involved in the conditioning procedures. Subjects in each group were given instructions designed to produce high expectancy for therapeutic success. Pre-post measures of alcohol consumption and attitudes toward alcohol were obtained using an analogue ‘taste test’ assessment procedure. No statistically significant differences in reduced alcohol consumption or attitudes toward alcohol were found among the groups. Trends in the data support the contention that effects of electrical aversion may be more related to such factors as therapeutic instructions, expectancy, specificity of the procedure or experimental demand characteristics than to conditioning factors.

An Attributional Analysis of Experimental Norms

Like other social situations, experimental encounters are conceived as normatively structured in terms of the dispositional attributions that participants make about one another. Experimental norms or demand characteristics provide individuals with ideas about appropriate and expected behavior. One of these norms seems to be that of reciprocity, such that a likeable experimenter is supposed to get positive responses to his stimuli from subjects interacting with him. It seemed to us that a well-known series of initiation severity in dissonance might be explicable in these terms. Thus, we conducted a simulational study where observers heard the same experiment, with spliced-in variations in introductory rationale and subjects' responses to mild or severe electrical shock. The tape modifications produced differences in observers' ratings of the experimenter, primarily along affective dimensions, and these differences related closely to stimulus-rating changes both among and within conditions. We concluded that dispositionally different experimenters are created by their participation in or responsibility for the manipulations that define conditions and that the kind of person he appears to be may often influence what people consider to be appropriate conduct toward him and expected reactions to his stimuli.

Experimenter Bias Effect as a Function of Demand Characteristics and Experimenter Investment

To clarify the nature of the Experimenter Bias Effect (EBE), the present study attempted to evaluate the influence of experimental demand characteristics and E's investment upon emergence of the EBE. The experimental design consisted of two 2 × 2 factorial designs in which Experimenter Expectancy and Experimenter Investment were each represented on two levels. The Rorschach inkblot test and Number Estimation Test were the tasks used in the two designs. The data did not reflect an EBE with either task or with any combination of experimental conditions. The present findings were discussed in terms of Es' inaccuracies in receiving and/or retaining the stated expectancy, Es' inabilities in identifying the intended demand characteristics, and the unreliable nature of the EBE.

Demand awareness, subject sophistication, and the effectiveness of a verbal "reinforcement"

Summary A cognitive or problem-solving interpretation of verbal conditioning was extended by making explicit the role of demand awareness and cooperation motivation in mediating the behavior. It was found that the word “reinforcement” itself was effective in producing verbal conditioning, and as predicted there was a highly significant difference between subjects who had taken a course in psychology and those who had not Postexperimental measures of contingency awareness, demand awareness and cooperation motivation all correlated with experimental performance That the strongest association was obtained when demand awareness plus cooperation motivation were considered was interpreted as indicating the crucial importance of these variables in mediating so-called verbal conditioning Data were interpreted as questioning the appropriateness of using the concepts of instrumental appetitive conditioning to describe so-called verbal conditioning. The effect seems to be an artifact of subjects cooperating with experimental demand characteristics