Demand characteristics refers to a problem which can distort
research. Demand characteristics as used in experimental psychology, refers to
unintended features of the experiment which affect the results, thus compromising the internal validity of the study.
The term demand characteristic is
also used in the sociology of deviant behavior to refer
to those organizational features of work settings, other than the formal goals of the
organizations or principles such as due process or
fairness, which shape arrest decisions, plea bargaining, or jury deliberations.
Examples of demand characteristics
which police officers may attend to in making decisions on the street are the informal
expectations of police culture, their work load, their
need to accumulate overtime or organizational rules.
Demand Characteristic is a term used
in Cognitive Psychology to denote the situation where the results of an experiment are
biased because the experimenters' expectancies regarding the performance of the
participants on a particular task create an implicit demand for the participants to
perform as expected.
Demand Characteristic result as we
do not simply respond to a situation or context because the meaning of such a situation or
context is not given, but requires interpretation.
Aspects of a research program or of
a researchers conduct, or even appearance, may cause the subject to guess the rationale of
the study and to attempt to confirm the experimenters hypothesis.
The problem is that particular cues
in an experimental situation may communicate to subjects what is expected and what the
experimenter hopes to find. Subjects might do what they think is expected,
demanded, of them rather than respond in any other way.
Demand characteristics have a clear link to Evaluation Apprehension where subjects come to
experiments/interviews expecting the possibility that they will be evaluated. Subjects may
then behave in a way that is thought to project a favorable image of themselves.
symptomatology: the role of social expectancy and experimental demand characteristics
- Psychosomatic Medicine, Vol 47, Issue 1 35-45, Copyright © 1985 by American
Psychosomatic Society - PG AuBuchon and KS Calhoun
The purpose of this study was to examine the effects of experimental demand
characteristics and social expectancies on the report and experience of presumed menstrual
cycle-related moods and symptoms. Participating in the study were 18 healthy women with
regular menstrual cycles who were randomly assigned to either a group told that menstrual
cycle symptomatology was the focus of the study or a group to which no interest in
menstrual cycle symptoms was communicated. Nine males were also included as a control
group. Results indicated that women who were informed of the interest in menstrual cycle
symptomatology reported significantly more negative psychologic and somatic symptoms at
the premenstrual and menstrual phases than did the women and men not so informed. It
appears, therefore, that the report of stereotypic menstrual cycle symptomatology is
influenced by social expectancy and experimental demand characteristics.
Demand characteristics in
body-size estimation in anorexia nervosa
The British Journal of Psychiatry 149: 113-118 (1986) © 1986 The Royal College of
L Proctor and S Morley
We asked 24 patients with anorexia nervosa and 30 normal controls to estimate their
body-size several times, each time using different instructions. The degree of
over-estimation was found to vary predictably with the wording of the instructions.
Informing the subject that she had made an error without specifying the direction of the
error resulted in reduced over-estimation on a subsequent trial, for both anorexics and
controls. 'Internally directed' instructions were associated with a greater degree of
over-estimation than 'external' instructions in both groups, but particularly in anorexic
subjects. Our results indicate the necessity of controlling the demand characteristics of
Demand characteristics, not
effort: The role of backpacks in judging distance
Robert Russell, Frank H. Durgin Department of Psychology, Swarthmore College
Abstract: Does wearing a backpack increase perceived distance, or does it simply encourage
subjects to increase numerical estimates? We first administered a questionnaire to
students describing an experiment in which subjects were required to wear a backpack while
making distance judgments. Nine of 14 subjects stated the "correct" (signed)
hypothesis; the other five made an unsigned prediction. This indicates that the backpack
hypothesis is transparent. In the explicit burden condition subjects were told they would
be wearing a heavy backpack while making distance judgments. In the implicit condition,
the same heavy backpack was worn, but it was described as being part of the equipment
necessary to operate the virtual reality. A no-backpack control condition was also run.
Because subjects made judgments in two different virtual environments, we expected that
people in the control and implicit conditions would believe that the experiment concerned
possible differences between the two environments. However, we expected people in the
explicit backpack condition to believe that they were to judge distances as farther than
they were. Based on an earlier replication of the backpack experiment outdoors with a male
experimenter, we only expected to find evidence of demand characteristics compliance among
women subjects. This prediction was borne out: Only female subjects in the explicit
heavy-backpack condition showed an increase in distance estimates. Wearing a heavy
backpack that was described as part of the VR equipment had no effect. We conclude that
effects of backpacks on judgments of distance are probably due exclusively to demand
characteristics and not to any actual change in perception when burdened.
Demand Characteristics and
Inferential Processes in Psychotherapeutic Change.
Horvath, Peter - Journal of Consulting and Clinical Psychology, v52 n4 p616-24 Aug 1984
Abstract: A brief narrative description of the journal article, document, or resource.
Offers evidence that demand characteristics referring to changes in clients' self-concepts
are the common factors in psychotherapies. Unassertive subjects (N=87) were assigned to
four types of imaginary role playing. Only the demand characteristics condition increased
significantly in assertiveness and self-esteem and decreased significantly in social
discomfort compared to controls.
Demand characteristics of
residential substance abuse treatment programs
Christine Timko, Katherine Yua and Rudolf H. Moosa
Journal of Substance Abuse, Volume 12, Issue 4, Winter 2000, Pages 387-403
Abstract: Purpose: This study examined the objective demand characteristics of treatment
programs in which substance abuse patients, or psychiatric patients, were residing. It
also examined associations of objective demand with substance abuse patients' perceived
expectations for functioning during treatment and patients' in-program participation.
Methods: A total of 994 patients living in 79 programs took part. Results: When patients
had a substance abuse rather than a psychiatric problem, objective demand characteristics
was higher: program policies had higher requirements for functioning and more resident
control; programs offered fewer health-treatment services; and the physical design
provided fewer safety features and socialrecreational aids. Compared to substance
abuse patients in low-demand programs, patients in high-demand characteristics programs
perceived the program to have higher expectations, in that the treatment climate exerted
more press to develop relationships, set goals, and be organized. Patients in high-demand
programs engaged more in self-initiated activities and participated more in treatment
services and program-organized events. Substance abuse patients' activity and
participation levels were determined jointly by the level of demand characteristics and by
the expectations for patients' expressiveness and self-understanding of their personal
problems. Implications: The findings illustrate the importance of considering objective
indices of demand in conjunction with perceived expectations to improve patients'
Demand Characteristics in
Assessing Motion Sickness in a Virtual Environment: Or Does Taking a Motion Sickness
Questionnaire Make You Sick?
Authors Sean D. Young, Bernard D. Adelstein, Stephen R. Ellis
Publisher IEEE Educational Activities Department Piscataway, NJ, USA
ABSTRACT: The experience of motion sickness in a virtual environment may be measured
through pre and postexperiment self-report studies
such as the Simulator Sickness Questionnaire (SSQ). Although research provides converging
evidence that users of virtual environments can experience motion sickness, there have
been no controlled studies to determine to what extent the user's subjective response is a
demand characteristic resulting from pre and posttest measures. In this study, subjects
were given either SSQ's both pre and postvirtual environment immersion, or only
postimmersion. This technique tested for contrast effects due to demand characteristics in
which administration of the questionnaire itself suggested to the participant that the
virtual environment may produce motion sickness. Results indicate that reports of motion
sickness after immersion in a virtual environment are much greater when both pre and
postquestionnaires are given than when only a posttest questionnaire is used. The
implications for assessments of motion sickness in virtual environments are discussed.
1 M.T. Orne, On the Social Psychology of the Psychological Experiment: With
Particular Reference to Demand Characteristics and their Implications, Am.
Psychologist, vol. 17, pp. 776-783, 1962.
2 O. Pfungst, Clever Hans: The Horse of Mr. Von Osten. Holt, Rinehart, and Winston, 1965.
3 R. Rosenthal, On the Social Psychology of the Psychological Experiment: The
Experimenter's Hypothesis as Unintended Determinant of Experimental Results, Am.
Scientist, vol. 51, pp.268-283, 1963.
4 J.W. Kanter, R.J. Kohlenberg, and E.F. Loftus, Demand Characteristics, Treatment
Rationales, and Cognitive Therapy for Depression, Prevention and Treatment, vol. 5,
p. 41, 2002.
5 A.K. Shapiro, A Contribution to a History of the Placebo Effect, Behavioral
Science, vol. 5, pp. 109-135, 1960.
6 A.K. Shapiro and E. Shapiro, Patient-Provider Relationship and Placebo
Effect, Behavioral Health: A Handbook of Health Enhancement and Disease Prevention,
J.D. Mattarazzo, S.M. Weiss, J.A. Herd, and N.E. Miller, eds., pp. 371-383,
7 H.S. Friedman, Health Psychology, second ed. Prentice Hall, 2002.
8 J.D. Frank, Persuasion and Healing. Johns Hopkins Press, 1973.
9 D.L. Paulhus, Measurement and Control of Response Bias, Measures of
Personality and Social Psychological Attitudes, vol. 1, J.P.Robinson, P.R. Shaver, and
L.S. Wrightsman, eds., pp. 17-59, Academic Press, 1991.
10 N. Schwartz, Self Reports: How the Questions Shape the Answers, Am.
Psychologist, vol. 54, no. 2, pp. 93-105, 1999.
11 S.R. Ellis, What Are Virtual Environments? IEEE Computer Graphics and
Applications, vol. 14, no. 1, pp. 17-22, 1994.
12 P. DiZio and J.R. Lackner, Alleviation of Motion Sickness and Postural
Instability during and after Virtual Environment Exposure, technical report, for
Naval Air Warfare Center Training Systems Division, Orlando, Fla., 1998.
13 R.S. Kennedy, J.E. Fowlkes, and M.G. Lilienthal, Postural and Performance Changes
in Navy and Marine Corps Pilots Following Flight Simulators, Aviation, Space, and
Environmental Medicine, vol. 64, pp. 912-920, 1993.
14 M.E. McCauley and T.J. Sharkey, Cybersickness: Perception of Self-Motion in
Virtual Environments, Presence: Teleoperators and Virtual Environments, vol. 1, no.
3, pp. 311-318, 1992.
15 R.S. Kennedy, Gaps in Our Knowledge about Motion Sickness and
Cybersickness, Proc. Motion Sickness, Simulator Sickness, Balance Disorders, and
Sopite Syndrome Conf., Sept. 1988.
16 R.S. Kennedy, K.M. Stanney, J.M. Drexler, D.E. Compton, and M.B. Jones,
Computerized Methods to Evaluate Virtual Environment Aftereffects, Proc.
Driving Simulation Conf. (DSC '99), pp.273-287, 1999.
17 R.S. Kennedy, N.E. Lane, K.S. Berbaum, and M.G. Lilienthal, Simulator Sickness
Questionnaire: An Enhanced Method for Quantifying Simulator Sickness, Int'l J.
Aviation Psychology, vol. 3, no. 3, pp. 203-220, 1993.
18 R.S. Kennedy and J.E. Fowlkes, Simulator Sickness Is Polygenic and
Polysymptomatic: Implications for Research, Int'l J. Aviation Psychology, vol. 2,
no. 1, pp. 23-38, 1992.
19 R.S. Kennedy, J.M. Drexler, and K.S. Berbaum, Methodological and Measurement
Issues for Identification of Engineering Features Contributing to Virtual Reality
Sickness, Proc. IMAGE VII, pp. 245-254, 1994.
20 S. Nichols, S. Cobb, and J.R. Wilson, Health and Safety Implications of Virtual
Environments: Measurement Issues, Presence: Teleoperators and Virtual Environments,
vol. 6, no. 6, pp.667-675, 1997.
21 S.R. Ellis, B.D Adelstein, S. Baumeler, G.J. Jense, and R.H. Jacoby, Sensor
Spatial Distortion, Visual Latency, and Update Rate Effects on 3D Tracking in Virtual
Environments, Proc. IEEE Virtual Reality Conf. (VR '99), pp. 134-139, 1999.
22 M.I. Hill, B.D. Adelstein, and S.R. Ellis, Achieving Minimum Latency in Virtual
Environment Applications, Proc. IMAGE Soc. Meeting, 2004,
23 S.R. Ellis, B.D. Adelstein, and R.B. Welch, Kinesthetic Compensation for
Rotational Sensorimotor Rearrangements: Demonstration with Experimental Controls,
Proc. Ann. Meeting of the Human Factors and Ergonomics Soc. (HFES), pp. 1551-1556, 2002.
24 R.H. So, W.T. Lo, and A.T.K. Ho, Effects of Navigation Speed on Motion Sickness
Caused by an Immersive Virtual Environment, Human Factors, vol. 43, no. 3, pp.
25 Power Calculator, Univ. of California, Los Angeles,
http://calculators.stat.ucla.edu/powercalc/, July 2006.
26 S.D. Young and D. Oppenheimer, Different Methods of Presenting Risk Information
and Their Influence on Medication Compliance Intentions: Results of Three Studies,
Clinical Therapeutics, vol. 28, no. 1, pp. 129-139, 2006.
27 R. Crow, H. Gage, S. Hampson, J. Hart, A. Kimber, and H. Thomas, The Role of
Expectancies in the Placebo Effect and Their Use in the Delivery of Health Care: A
Systematic Review, Health Technology Assessment, vol. 3, no. 3, pp. 1-96, 1999.
28 K. Beecher, The Powerful Placebo, J. Am. Medical Assoc., vol. 159, pp.
29 I. Kirsch, Response Expectancy as a Determinant of Experience and Behavior,
Am. Psychologist, vol. 40, pp. 1189-1202, 1985.
30 I. Kirsch, The Placebo Effect as a Conditioned Response: Failures of the
Litmus Test, Behavioral and Brain Sciences, vol. 14, pp. 200-204, 1991.
31 I. Kirsch, Specifying Nonspecifics: Psychological Mechanisms of Placebo
Effects, The Placebo Effect: An Interdisciplinary Exploration, A. Harrington, ed.,
pp. 166-186, Harvard Univ. Press, 1997.
32 K.L. White, The Task of Medicine: Dialogue at Wickenbug. The HenryJ. Kaiser Family
33 D.E. Moerman and B.J. Wayne, Deconstructing the Placebo Effect and Finding the
Meaning Response, Annals of Internal Medicine, vol. 136, no. 6, pp. 471-476, 2002.
34 R.A. Hahn, The Nocebo Phenomenon: Scope and Foundations, The Placebo
Effect: An Interdisciplinary Exploration, A. Harrington, ed., pp. 56-76, Harvard Univ.
35 M.G. Myers, J.A. Cairns, and J. Singer, The Consent Form as a Possible Cause of
Side Effects, Int'l J. Clinical Pharmacology and Therapeutics, vol. 42, pp. 250-253,
36 G.R. Grice, Dependence of Empirical Laws upon the Source of Experimental
Variation, Psychological Bull., vol. 66, pp. 488-498, 1966.
37 S.D. Young and D. Oppenheimer, Lost in Translation: The Cognitive and Behavioral
Effects of Semantic Presentation of Risk Information, J. Behavioral Decision Making,
38 D. Kahneman and A. Tversky, The Psychology of Preferences, Scientific Am.,
vol. 246, pp. 160-173, 1982.
39 Multiple Articles in Section: Spotlight on Simulator Sickness, Presence:
Teleoperators and Virtual Environments, vol. 1, no. 2, pp.295-363, 1992.
40 J. Cohen, Statistical Power Analysis for the Behavioural Sciences. Academic Press,
41 J.T. Reason and J.J. Brand, Motion Sickness. Academic Press, 1975.