The Psychological Record, 2009, 59, 155–170
Reviving the Milgram Obedience Paradigm
in the Era of Informed Consent
Douglas J. Navarick
California State University, Fullerton
Participants repeatedly chose between 25 s of cartoon video followed by 5 s of
time-out and 5 s of cartoon video followed by 25 s of time-out. In the first 15 min,
participants chose the former schedule on 80% of trials. In the second 15 min,
they were instructed to choose only the latter. When informed that leaving would
not be a problem for the researcher because enough data were already collected,
approximately 20% quit. When participants were additionally instructed that
most participants withdrew, approximately 50% of them quit, a result supporting Milgram’s (1965a) hypothesis that disobedience increases when it appears
to be normative. As in Milgram’s experiments, participants were more likely
to withdraw on early trials than on later trials. Operant procedures involving
instructions to choose a mildly aversive schedule offer an alternative to simulations as a way of investigating the conflicts and escape processes characteristic
of the Milgram obedience paradigm.
In the 1960s Stanley Milgram (1963, 1965a, 1965b, 2004) conducted a series
of experiments that explored the conditions under which people could be
induced to harm and potentially kill someone they did not know on the orders
of a person who occupied a position of authority in a prestigious institution.
The objective was to reproduce the kind of destructive obedience that Milgram
(2004) maintained was essential to sustaining the bureaucratically managed
forms of mass murder that occurred in Europe during World War II.
Paid participants from a wide range of occupations were recruited by a
newspaper ad and direct mail to serve in a 1-hr experiment on memory and
learning at Yale University. Two participants arrived for each session, one
of whom was an accomplice of the researcher. Based on a rigged drawing,
the genuine participant was assigned the role of teacher and the accomplice
the role of learner in a task involving the memorization of word pairs. The
experimenter instructed the teacher to press levers on a shock console that
ostensibly delivered progressively stronger shocks to the learner whenever
he selected the wrong word on a multiple-choice test. If the teacher showed
I thank Kelly Deegan and Steve Perez for their invaluable assistance. Portions of these data
were presented at the meetings of the Association for Behavior Analysis, San Diego, May 2007.
Correspondence concerning this article should be addressed to Douglas J. Navarick, Department
of Psychology, PO Box 6846, California State University, Fullerton, CA 92834-6846. E-mail:
[email protected]
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NAVARICK
reluctance to continue, the experimenter issued commands of increasing
severity, culminating with, “You have no other choice; you must go on”
(Milgram, 2004, p. 21). In the famous voice feedback condition (Milgram, 1965b,
2004), 62.5% of participants were fully obedient, pressing all 30 of the levers
(with the maximum intensity listed as 450 V) despite hearing increasingly
anguished cries and protests from the learner. Participants often exhibited
distress when they heard these reactions.
The stress, deception, and experimenter pressure that Milgram’s
participants experienced provoked a debate on the boundaries of ethically
acceptable research. Institutionalized standards of review emerged from this
debate and eventually ended Milgram-style experiments in the United States
by the mid-1970s and in other countries by the mid-1980s (Blass, 1991, p. 6).
Despite the absence of ongoing research on obedience, Milgram’s findings
continue to be cited in discussions of diverse forms of destructive behavior,
including suicide terrorism (Atran, 2003) and military prisoner abuse (Fiske,
Harris, & Cuddy, 2004; cf. Zimbardo, 2007).
Some research related to Milgram’s has continued in the form of
simulations, for example, role-playing in a setting closely resembling the
original one (Geller, 1978) and having participants administer “shocks” to a
character created through virtual reality technology (Slater et al., 2006). The
simulations seek to produce the original, destructive form of obedience but
with the provision that participants are assured that no one will be shocked
and the participants can leave at any time in accordance with informed
consent procedures.
An alternative approach, explored in the present study, is to employ
a mildly aversive, nondestructive form of obedience in a conventional
experimental setting. It is predicated on the assumption that one need not
give a participant orders to commit morally repugnant acts to set in motion
the fundamental conflict between obeying the commands of authority and
avoiding aversive consequences. Necessarily absent would be the sweating,
trembling, and other symptoms of emotional strain that were sometimes
observed among Milgram’s participants, most of whom indicated on a
rating scale after the session that they experienced moderate to severe
levels of “tension and nervousness” (Milgram, 2004, p. 42). In that sense, no
contemporary experiment could model the Milgram paradigm. However, a
milder level of aversiveness is just as relevant if the goal is to model the
destructive obedience that occurs in natural settings. In his preface, Milgram
wrote, “Behavior that is unthinkable in an individual who is acting on his
own may be executed without hesitation when carried out under orders.” The
present approach focuses on this form of obedience, which occurs “without
hesitation” in the sense of requiring no additional orders after the initial
instructions are given to maintain the behavior.
In any experiment the researcher presents instructions that describe
behavior the participants must perform to remain in the experiment. A clear
hierarchical structure exists, with the experimenter occupying a position
of greater authority within the institution than the participant. When
participants follow the instructions, they may experience a form of discomfort
such as boredom, frustration, or embarrassment. Because they are instructed
that they can leave at any time, their choice to continue would suggest that
there are uncontrolled factors in the current setting or the participants’
preexperimental history that deter withdrawal and thus function similarly to
Obedience and Choice
157
the commands in Milgram’s experiments. With this assumption of implicit,
ongoing commands that deter withdrawal, any conventional experiment that
provides minimal positive reinforcement potentially fits within the Milgram
paradigm. One purpose of the present experiment was to identify some of
these implicit commands by removing possible deterrents to withdrawal
suggested by studies of obedience as well as by studies of compliance with
experimental demand characteristics (Orne, 1962, 1970).
Of particular interest was the role of conformity to the performance
of other participants, the factor that Milgram (1965a, 2004) found was the
most influential in reducing obedience. In his 1965a study, two confederate
participants assisted with the task, one of whom read the words to the learner
while the other stated whether the learner’s answers were correct or incorrect.
The genuine participant pressed the shock levers on the console. Defying the
demands of the experimenter, the former confederate refused to continue
after the participant had pressed 10 of the 30 levers, and the latter refused
to continue after the participant had pressed 14 levers. Both confederates
remained seated in the room while the participant assumed their roles.
Milgram (1965a) found that in the baseline condition where participants were
alone, 26 of 40 pressed all 30 of the levers, whereas in the group condition
only 4 of 40 reached the highest level of obedience. The mean break-off point
(the highest level reached before quitting) correspondingly decreased from
24.55 to 16.45.
Among the factors that Milgram (1965a, pp. 132-133) suggested may have
contributed to the group’s influence was the representation of defiance as a
“common occurrence” and a “natural reaction to the situation.” The present
study sought to create a similar representation of normative behavior by
having the experimenter include in one condition the statement that “most
of our participants do leave before the experiment is over.” A reduction in
the proportion of participants who were fully obedient would suggest that
conformity to the behavior of most other participants is one of the implicit
commands that maintain obedience to an experimenter’s instructions.
Obedience as Choice Behavior
Milgram (2004) theorized that his participants experienced an “aversive
state” (p. 44) as a result of tension arising from the conflicting tendencies to
obey the experimenter and to help the victim. This tension was characterized
as a source of drive that increased the potential for escape behavior. In terms
of operant conditioning, the type of consequence associated with escape
is negative reinforcement. At every step of the procedure the participant
had a choice between quitting and obtaining negative reinforcement
after a relatively short delay or pressing the lever and obtaining negative
reinforcement after a longer delay. As more and more levers were pressed, the
delay of reinforcement associated with completing the study decreased while
the delay associated with quitting remained constant, a contingency that
should increasingly have favored the choice to continue. Such progressively
shorter delays of reinforcement may have constituted one of the situation’s
“binding factors” that Milgram (2004) theorized promoted obedience.
A potential role for delay of reinforcement in obedience is supported by
studies of choice in nonhuman species (Fantino, 1969, 2000; Fantino, Preston,
& Dunn, 1993) as well as studies with humans responding for consumable
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(intrinsic) reinforcers (Navarick 1996, 2001) that show that relatively short
delays of reinforcement are preferred to longer delays, even if the shorter
delay results in a smaller reinforcer (especially in nonhuman species), a
preference that is often characterized in terms of impulsivity (Navarick &
Fantino, 1976; Navarick, 2004).
Particularly relevant is a study by Navarick (1982) in which college
students chose between schedules of negative reinforcement in which the
reinforcement was cessation of white noise delivered through headphones. In
a discrete-trials procedure, pressing one key turned off the noise immediately
for 5 s, whereas pressing the other key turned off the noise for 20 s after
delays of 20, 40, 60, or 75 s, with the postreinforcement intervals (containing
noise) adjusted to equalize the rates of access to the schedules. The median
choice proportions for the immediate, 5-s reinforcer (analogous to quitting)
at the various delays were .09, .36, .44, and .94, respectively.
Extrapolating to the obedience paradigm, if the same pattern held, the
preference to escape by quitting would be maximal near the start of the
session (analogous to the 75-s delay) and then drop precipitously as the
session continued, with a slower rate of decline thereafter. Indeed, Milgram
(2004) found such patterns of withdrawal, and they contributed importantly
to his theory of obedience.
Method
Participants
A total of 100 students from introductory psychology classes participated
in partial fulfillment of an experimental-hours requirement. Data from
7 additional participants were excluded from the analysis because the
participants did not meet a baseline preference criterion described below. For
the seven groups studied, the mean proportion of female participants was .66
(SD = .14, SEM = .05). Students were able to choose among available studies
on the basis of brief, descriptive titles. The present experiment was entitled
“Cartoon Viewing” to increase the likelihood of recruiting students for whom
the cartoon videos would be an effective reinforcer.
General Procedure
Participants responded in a discrete-trials choice procedure that was
previously used to study compliance with experimenter requests to choose a
nonpreferred schedule of reinforcement (Navarick, 2007). Session durations
were scheduled for 1 hr, as in Milgram’s studies. The reinforcer was a cartoon
video that was selected by the participant at the beginning and midway
through the session from a list of 26 classic and contemporary titles.
The participant initially was seated in a reception room that housed
the programming equipment for the experiment and was read an informed
consent statement, which included the assurance that their participation
was voluntary and that they could leave at any time and still keep their
participation credit. The participant signed two copies of the statement,
keeping one of them, and was then accompanied to an adjacent room in which
the session was conducted. This room, measuring 2.7 m × 2.1 m, was unlit
while the session was in progress.
Obedience and Choice
159
The participant sat facing a video monitor and a response console with
two disks. The experimenter, referring to a desk bell on top of the console,
stated, “If you decide to leave before the experiment is over, you can tap
on the bell there and I will come in and end the experiment.” When the
disks were illuminated, a press on either one turned off both key lights and
immediately started the video. On one side the video played for 25 s, after
which the picture and sound were removed for 5 s. On the other side, the
cartoon played for 5 s, after which the picture and sound were removed for
25 s, which in effect imposed a time-out from the positive reinforcement that
was available on the alternative schedule. When the video resumed on the
next trial, it started at the point where it had previously stopped. When trials
were being administered, the experimenter stayed in the adjacent room.
Participants were instructed that the session would be in two parts, each
lasting “about 15 minutes.” The first part consisted of 4 forced-choice trials
in which participants were instructed to press the keys in the sequence, leftright-left-right, followed by 20 free-choice trials. The free-choice trials in
Part 1 served as a baseline to assess preference. The 25-s reinforcer schedule
was assigned to the side opposite the participant’s stated hand preference
so that a preponderance of choices for that side would more plausibly be
attributable to schedule preference than to position preference. Participants
were excluded from the analysis (a total of 7) if they chose the 5-s reinforcer
schedule on the majority of trials during the baseline phase.
The second half of the session (Part 2) was the obedience phase, in
which the experimenter instructed the participant to press only the key that
produced the brief period of reinforcement followed by time-out. Twenty such
trials were administered, prior to which the participants were instructed to
press the keys in the sequence left-right-left-right to facilitate generalization
from Part 1. As in Milgram’s studies, the degree of obedience was measured
in two ways: by the proportion of participants who quit before the last trial
and by the average number of trials they completed before quitting.
The aversiveness of the 5-s reinforcer schedule is supported both by
choice data and by debriefing statements from both Navarick (2007) and the
present study (see the Results section). In the previous study most participants
characterized the designated schedule in terms of discomfort, the most
common term being “annoying.” One participant stated, “I tried to press the
right button more because you said you preferred me to. But I didn’t like
sitting in the dark, waiting, so it was hard…it was better to watch something
than to sit around with nothing to do” (Navarick, 2007, p. 509).
Instructions for Obedience Phase
After the 20th free-choice trial in Part 1 was completed, the experimenter
returned and read instructions that varied according to the participant’s
group. Participants in the Escape Group (E) were simply instructed to choose
the designated schedule. The desk bell on the console allowed for a withdrawal
response that was as explicit and simple to perform as the response that
represented continuing, that is, pressing the key. To reduce possible habituation
to the reinforcer, participants were offered the option of switching to a different
cartoon. The instructions for the E Group were as follows:
We’ll now start the second part of the experiment. As before, the
first time the disks are lit, press left; the second time, press right;
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160
the third time, left; the fourth time, right. After that, please press
the disk only on the [nonpreferred] side. Would you like to stay with
the same cartoon or switch to another one? Again, the first time the
disks are lit, press left, then press right, then left, then right. After
that, please press the disk only on the [nonpreferred] side.
For the Escape/Approval Group (EA), instructions were added to alter
the study’s demand characteristics (Orne, 1962, 1970), cues that convey a
researcher’s expectations or preferences about the results and that may induce
behavior consistent with those cues because of participants’ motivation to
help the researcher. To offset possible associations between quitting and
interfering with the research, the experimenter concluded the instructions
with the following lines:
As I mentioned when we started, you can ring the bell at any time
and leave the experiment before it is over. If you decide to leave,
it’s not a problem for us because you already finished Part 1, and
we can still use the results even if you don’t finish Part 2.
Rather than express a specific expectation or preference for withdrawal,
the added statement made the option of withdrawal more salient and implied
that it would result in a congenial reaction on the part of the researcher.
For the Escape /Approval / Norm Group (EAN), the experimenter
additionally stated, “Most of our participants do leave before the experiment
is over.” For the EAN+ Group, the experimenter elaborated on that line by
looking up from the instruction sheet and stating casually, “Actually, they
leave after just a few minutes.” Without this line, the ostensible norm could
have extended to a point in the session where quitting offered relatively little
temporal advantage over staying. The experimenter’s statement served to
move the norm to a point where quitting would be more advantageous.
Design
Groups were studied sequentially in two series that differed in several
respects, which provided a test of the replicability of the effects under
substantially changed conditions.
For Series A, conducted during a spring semester, the experimenter was a
female graduate student and the research-participation management system
was paper based, with the experimenter giving the participant a credit
receipt when he or she arrived for the session. The order of conditions was
Escape (E), Escape/Approval (EA), and Escape/Approval/Norm (EAN). This
order was followed because the quit rate found in each condition was used as
the basis for formulating the next condition. However, the period during the
semester when a group was studied was a potentially influential confound.
For example, Group EAN, which was designed to maximize the quit rate, was
studied during the last several weeks of the semester when an accumulation
of academic assignments could have enhanced the value of any free time
the student would have obtained by quitting. There also could have been
dispositional differences between students who signed up later versus earlier,
for example, in the extent to which research participation was an intrinsically
reinforcing activity (cf. Harber, Zimbardo, & Boyd, 2003).
For Series B, conducted more than a year later during a fall semester, the
groups were studied in reverse order so that EAN would be at the start of the
Obedience and Choice
161
semester when, by the previous reasoning, any predisposition to withdraw
would have been weakest, thus permitting a clearer test of the normative
instructions. In Series B, the experimenter was a male graduate student and
the research-participation management system was computer based, with
credit recorded in the student’s web account after the session. Group EAN+
was studied during the same period as Group EAN, and the participants were
randomly assigned to these two groups.
There were 15 participants in each group except Group E, Series B, in which
there were 10 participants. Also, in Group E, Series B, 4 of the participants
were female, in contrast with Group E, Series A, in which 12 of the participants
were female.
Data Analysis
The main dependent variable was the proportion of participants who
quit before they pressed the key on the 20th free-choice trial. In Milgram’s
terms, these would be participants who were not fully obedient. Significance
was assessed by calculating the 95% confidence interval for each group’s
proportion using the modified Wald method suggested by Agresti and Coull
(1998). The proportions of two groups were significantly different if each
group’s proportion fell outside the 95% confidence interval of the other
group. The mean number of trials completed before quitting (analogous to
Milgram’s break-off points) was assessed using one-way analyses of variance,
and Tukey’s HSD tests were used for the post hoc pairwise comparisons. All
statistical tests employed a two-tailed, .05 significance level.
The proportions of choices for the 5-s reinforcer schedule were calculated
in the baseline phase to estimate the degree to which the target schedule was
avoided before participants were instructed to choose it and to determine
whether the choice proportions differed significantly across groups. The
choice proportions were also analyzed in the obedience phase to assess the
extent to which obedience included performing the instructed behavior. It was
possible that participants would remain in the session until completion but
choose their preferred schedule instead of the designated one. Such behavior
would be analogous to participants in Milgram’s studies administering lower
levels of shock than those required by the procedure, a form of behavior
that Milgram (2004) referred to as “subterfuge.” Such behavior was said to
represent a compromise between withdrawal and complete obedience and to
offer partial escape from the aversive procedure.
Results
In the baseline phase for Series A, the mean choice proportion among
the three groups for the 5-s reinforcer schedule was .20; for Series B the
mean choice proportion among the four groups was .19. Analysis of variance
showed no significant differences within either series. For each group a t
test was conducted on the difference between the group’s mean and a range
of hypothetical population means. All seven groups had means significantly
below .35, and five of the seven groups had means significantly below .30.
The effects of instructions on withdrawal rates during the obedience
phase are shown in Figure 1. Groups in Series A are represented by shaded
bars and groups in Series B by unfilled bars. The upper and lower limits
NAVARICK
162
of the 95% confidence intervals, as calculated by the method of Agresti and
Coull (1998), are shown within the bars. The effect of the statement about
most participants leaving the experiment before it was over can be assessed
by comparing the proportions of participants who quit in Groups EAN and EA
within each series. Within both series the quit rates of EAN slightly exceeded
the confidence intervals of EA, and the quit rates in EA fell below the
confidence intervals of EAN. By the criteria stated in the Procedure section,
these proportions were significantly different.
0.9
n = 15
Proportion of Participants Who Quit
0.8
Series A
(Female Experimenter)
0.7
Series B
(Male Experimenter)
0.6
95%
Confidence
Interval
0.5
0.4
0.3
0.2
0.1
0
n = 10
Escape
Escape/Approval Escape/Approval/Norm Escape/Approval/Norm+
Group
Figure 1. The proportion of participants in Groups E to EAN+ who indicated their choice
to leave the experiment by tapping on a desk bell.
It is noteworthy that comparisons across series gave inconsistent results
due to the higher quit rates in Series B than in Series A. Group EAN in Series
A and Group EA in Series B had proportions that fell within each other’s
confidence intervals. However, EAN in Series B and EA in Series A each had a
proportion that was outside the other group’s confidence interval. Although
incidental aspects of the procedure such as the specific person serving as
the experimenter and the particular semester in which the sessions were
conducted may have influenced the absolute quit rates, the instruction that
described normative behavior had a consistent effect when such factors were
held constant. The additional statement in Group EAN+ about participants
leaving after just a few minutes produced no significant increase in
withdrawals as compared with Group EAN, but the withdrawal rate in Group
EAN+ was slightly higher than in EAN and constituted a second replication of
the instructed norm effect.
Obedience and Choice
163
The effect of advising participants that withdrawing would not be a
problem for the researcher can be assessed by comparing the quit rates in
Groups EA and E. No withdrawals occurred in Group E. However, in Group EA,
2 participants withdrew in Series A and 4 withdrew in Series B. In both cases
the proportions fell within the confidence intervals of Group E regardless of
the series that was used for comparison. Considering the similarity of the
results in the two EA groups, and the identical results in the two E groups,
there would be a basis for combining the data from the two series. With the
larger sample sizes (30 and 25, respectively), the proportions, .20 and .00,
would be significantly different. The lower limit of the confidence interval for
.20 would be .09, and the upper limit of the confidence interval for .00 would
be .16. Therefore, averaging over both series, the approval statement may
have produced withdrawals in about 20% of participants. With an average
withdrawal rate in Groups EAN and EAN+ of about 50%, one could infer that
the statement describing normative behavior probably produced withdrawals
in about 30% of participants.
Mean trials completed was a less sensitive measure of the effects of
instructions than was the proportion of the group that failed to reach the last
trial. Going from Group E to EAN in Series A, the means were 20.00, 17.93,
and 14.47, and in Series B the means were 20.00, 15.27, and 10.60 (10.87 in
Group EAN+). Within each series, analysis of variance showed a significant
group effect (Series A: F = 3.696, df = 2, p = .033; Series B: F = 3.693, df = 3, p =
.018). However, in pairwise comparisons, Tukey’s HSD tests found significant
differences only between Groups E and EAN and Groups E and EAN+.
Whether participants completed all of the trials or withdrew, most
chose the designated key on virtually every trial. Of the 100 participants,
91 had choice proportions of 1.00 for the 5-s reinforcer schedule. Among
the 9 participants who sampled their preferred schedule, all but 1 chose
the designated schedule on the majority of trials. Six of the 9 participants
completed the session; their choice proportions were .95, .95, .95, .90, .80, and
.10. The 3 participants who quit the experiment had choice proportions of
.93, .67, and .67. The choice proportion of .10 was from a female participant in
Group E, Series B. In the debriefing she stated that she disobeyed instructions
because she “thought it was ridiculous to sit in darkness.” Considering that up
to half of the participants quit the experiment in some groups, the rarity of
such extreme defiance underscores the differential effects of the instructions
on the two forms of escape that were available to participants.
A total of 29 participants from all of the groups withdrew before the 20th
trial. Figure 2 depicts the proportion of these participants who quit after
completing 0 to 19 trials.
Simple sign tests support the generalization that participants were
far more likely to quit on early trials than on later ones. For example, 25
participants quit on Trials 0–9 and 4 quit on Trials 10–19. With a hypothetical
probability of .50 for a participant falling into either categeory, the obtained
distribution would occur with a two-tailed probability of .0001. Similarly, 22
participants quit after 0–4 trials and 3 quit after 5–9 trials, resulting in a
probability of .0002. Regarding the sharp drop in the curve after 2 trials,
16 participants quit after 0–2 trials and 6 after 3–5 trials. The two-tailed
probability was .052 and the one-tailed probability was .026, which together
would seem to provide at least marginal statistical support for this portion
of the function.
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164
Proportion of Quitting Participants
0.25
n = 29
0.2
0.15
0.1
0.05
0
0
1
2
3
4
5 6
7 8
9 10 11 12 13 14 15 16 17 18 19
Trials Completed Before Quitting
Figure 2. The proportion of all 29 participants who quit as a function of the number trials
they completed before quitting.
In Series A the experimenter conducted debriefings in which participants
were questioned in a scripted but conversational manner, and closely
paraphrased summaries of their replies were recorded immediately after
the participants left the reception room. That quitting functioned as a form
of escape is supported by statements from participants who quit in Groups
EA and EAN. When they were asked why they quit, 7 of the 8 participants
clearly characterized the designated schedule in terms of discomfort. For
example, one participant from Group EA replied, “I just couldn’t sit there any
longer. The right side was way too short and there was this long wait between
the cartoons. I don’t like the dark so I didn’t like sitting there in the dark. I
also had a hard time following the video.” A participant in Group EAN said,
“Because it was so short, and the time in between switching back and forth
was annoying. I didn’t like the wait.” Another participant in EAN replied,
“Because the wait was so long and I hated sitting in the dark. The cartoon was
also a lot shorter.”
Discussion
One of Milgram’s (1965a) major findings on obedience was that the
control exerted by the experimenter over the participant was undermined
by the presence of other participants who defied the experimenter’s
orders. The proportion of participants who were fully obedient decreased
when two confederate participants quit the experiment but remained in
the room while the genuine participant assumed their duties. Milgram
proposed that the confederates’ effect may have been due partly to
representing defiance as a “common occurrence” and appropriate to
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165
the circumstances. The present experiment supports this hypothesis.
For Groups EAN and EAN+, the instructions indicated that withdrawal
was a common occurrence, and these groups had significantly higher
withdrawal rates than Group EA.
Although it was possible to show an analogous kind of group influence,
the instructed norm had a comparatively weak effect, considering that in the
present case withdrawal came against the backdrop of implicit experimenter
approval, whereas in Milgram’s case withdrawal came against the backdrop
of explicit experimenter disapproval and so constituted blatant defiance.
Nevertheless, the effect of the instructed norm was substantial, increasing
withdrawals from about 20% in Group EA to about 50% in Groups EAN and
EAN+. For some participants, conformity to the behavior of other participants
was a decisive factor in withdrawal when demand cues set the stage for this
behavior but were not sufficient to produce it.
Behavioral Processes
The distribution of quits across trials depicted in Figure 2 helps to
clarify the behavioral processes that influenced participants’ choices to
withdraw. As previously discussed, the steeply negatively accelerated curve
is consistent with a process of escape in which one response, tapping the
bell, was associated with a shorter delay to negative reinforcement than the
alternate response, pressing the key. As trials continued, the delay associated
with key pressing progressively decreased, thereby reducing the temporal
advantage associated with the bell.
Another behavioral process that could have contributed to withdrawals
was the direct punishment and weakening of obedient choices by the
designated schedule. However, if punishment were the predominant process,
and the effects of repeated punishments were cumulative, one would expect
to find an increase rather than a decrease in the proportion of quits as a
function of trials.
A decreasing function suggests an interplay of classical and operant
conditioning along the lines described by the two-process theory of avoidance
learning (Kamin, 1956; Mowrer, 1947). The aversive consequences of obedient
choices become associated with contextual stimuli through classical
conditioning, and the withdrawal response is then negatively reinforced by
the removal of these newly aversive stimuli. This dual-process account would
be closer to Milgram’s interpretation of obedience as discussed earlier, in
which participants are said to experience an aversive state of tension that
motivates them to escape.
The dual-process account leaves unexplained most participants’ choice
to escape by leaving rather than by remaining and choosing their preferred
schedule. The instructions appeared to have functioned as an establishing
operation (Michael, 1982, 2000), an antecedent event such as food deprivation
that alters the reinforcing or punishing effects of a consequence. The
statements that leaving would not be a problem for the researcher and that
most participants did leave could have made any covert verbalization that
potentially mediated withdrawal less aversive. In contrast, the experimenter
never stated approval for choosing the alternative schedule or indicated that
other participants had made such choices, so the aversive effects of pressing
the nondesignated key would be unchanged.
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Delay of Reinforcement as a Binding Factor
Milgram (2004) proposed that a variety of antecedent conditions
induced the individual to become an agent of the authority figure,
and once in this agentic state the individual was strongly disposed to
carrying out orders irrespective of their consequences (provided that
the orders were consistent with the authority’s role and appropriate to
the context) and largely independently of the individual’s personality
characteristics. The agentic state was seen as the product of an inherently
unstable hierarchical structure and dependent on binding factors to be
sustained.
One binding factor was said to be the repetitive nature of the behavior
that the participant was ordered to perform. The behavior would generate
its own momentum because, in Milgram’s view, the participant would
engage in a process of self-justification wherein each repetition of the act
added to the psychological cost that would be incurred by quitting and
acknowledging that the previous obedience was an error in judgment.
Recurrent behavior that is increasingly likely to be repeated also
may signify a reinforcement process such as the one discussed above.
If the distribution of quits in Milgram’s studies resembled the present
one, the implication would be that the underlying process of escape was
independent of the particular means used to make the consequences of
obedience aversive. In other words, the escape process would not depend
on a participant’s engaging in a form of moral reasoning related to a
command to harm others, such as the self-justification process that
Milgram hypothesized.
Figure 3 presents data on quit rates in relation to the number of levers
pressed from three groups in Milgram’s proximity series (Milgram, 1965b,
2004) in which he varied the type of feedback that the teacher received
from the learner: voice feedback, auditory only; proximity, auditory +
visual (the learner was seated in the same room and was visible to the
teacher); and touch proximity, auditory + visual + touch (the teacher
was required to place the learner’s hand on a metal plate to administer
shock). Overall, the proportion of participants who reached the highest
shock level was .625 in voice feedback, .40 in proximity, and .30 in touch
proximity. In the present experiment, obedience rates were reduced to
comparable levels. The average proportion of participants who completed
all of the trials was 1.00 in Group E, .80 in Group EA, .57 in Group EAN,
and .40 in Group EAN+.
Figure 3 presents recalculations from Milgram’s data on break-off
points. Using data from participants in a group who stopped before
administering the highest shock level (30), the curve represents the
proportion for whom the indicated levels were the highest ones reached.
These curves may be compared with the analogous curve in Figure 2
with the following qualifications. First, Figure 3 starts with shock level 6,
whereas Figure 2 starts with Trial 0, the period preceding the first trial
for which participants were instructed to press only the nonpreferred
key. Second, Milgram’s procedure had additional trials between the
trials listed because the learner occasionally gave “correct” answers.
The present procedure administered the aversive consequence on every
trial.
Obedience and Choice
167
Proportion of Quitting Participants
0.6
0.5
Voice Feedback, n = 15
Proximity, n = 24
Touch Proximity, n = 28
0.4
0.3
0.2
0.1
0
6
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Highest Shock Level Reached
Figure 3. Calculations of quit rates based on break-off point data from Milgram’s (1965b,
2004) proximity series.
All three curves in Figure 3 are unimodal with their peaks at Level 10,
where the learner first demanded to be let out. The heights of the modes vary
across groups in the same manner as the overall proportions of participants
who were not fully obedient, indicating that the partially obedient participants
were sensitive to the feedback variable relatively early in the session. In all
of the groups, more than half of the quitting participants quit before shock
level 15, the midpoint of the scale.
There are several similarities to Figure 2: The modes occur in the first
half of the obedience trials, and they are followed by sharp drops on the
next trial and then by shallower declines that reach negligible levels near
the end of the session. Such negatively accelerated curves are consistent
with a process of making choices between quitting and continuing on the
basis of relative delays of reinforcement that are changing across trials.
In Milgram’s experiments and in the present one, participants appear to
have been primed to withdraw during the early trials in which aversive stimuli
were presented (relatively mild expressions of pain and repeated exposures to
the time-out, respectively) and before an appropriate occasion for withdrawal
emerged (shock level 10, where the learner demanded to stop, and the first few
choice trials in Part 2, showing that the time-out schedule would be the same
as in Part 1). Once the discriminative stimulus for withdrawal occurred, the
probability of withdrawal appears to have been influenced predominantly by
the choice between escaping an aversive environment after a relatively short
delay and escaping after a longer delay.
168
NAVARICK
An example of withdrawal that seems to have resulted mainly from
cumulative punishment can be seen in a virtual reality simulation of
Milgram’s proximity condition by Slater et al. (2006). The participant wore
stereoscopic glasses as he or she viewed a projected display showing the
learner (female; Milgram’s was male) facing the participant on the other side
of a window. The participant was assured that no one would be shocked. In
the Visible Condition, the learner could be seen and heard throughout the
test, whereas in the Hidden Condition (analogous to the remote condition
in the proximity series, not shown in Figure 3) she was visible only when
introduced at the beginning of the session. The learner gave wrong answers
on 20 of the 32 test trials, with increasingly severe reactions to the shocks
(verbal expressions of pain, facial expressions, and head movements) in the
Visible Condition.
The proportion of participants who withdrew was significantly higher
in the Visible Condition (7/24) than in the Hidden Condition (0/11). Three
participants withdrew after giving 19 shocks and 4 after giving 18, 16,
9, and 5 shocks, respectively. Skin conductance levels and heart rates of
participants measured when they administered shocks were higher in
the Visible Condition than in the Hidden Condition, and these differences
increased across test trials, suggesting that the learner’s reactions were
increasingly stressful to the participants. There was direct behavioral
evidence for cumulative punishment: For shock levels 19 and 20, when
the learner failed to answer, participants in the Visible Condition waited
significantly longer before pressing the button to deliver the shock than did
participants in the Hidden Condition.
Overall, Slater et al. (2006) appear to have produced a process of
sensitization rather than habituation to the aversive consequences of
obedience. In contrast, Milgram’s view was that individuals caught up
in the social structures responsible for destructive obedience were more
likely to become inured than sensitized to the consequences of their
acts.
To investigate obedience, researchers have traditionally sought to
create explicit correspondences to the procedural elements of the Milgram
paradigm, such as participants reading word pairs and administering
shocks, and the victim reacting with expressions of pain. The present
experiment illustrates an alternative approach in which one explores the
generality of the paradigm by creating conceptual analogues to it in new
situations.
References
Agresti, A., & Coull, B. A. (1998). Approximation is better than exact for
interval estimation of binomial populations. The American Statistician,
52, 119–126.
Atran, S. (2003). Genesis of suicide terrorism. Science, 299, 1534–1539.
Blass, T. (1991). Understanding behavior in the Milgram obedience
experiment: The role of personality, situations, and their interactions.
Journal of Personality and Social Psychology, 60, 398–413.
Fantino, E. (1969). Choice and rate of reinforcement. Journal of the
Experimental Analysis of Behavior, 12, 723–730.
Obedience and Choice
169
Fantino, E. (2000). Delay reduction theory—the case for temporal context:
Comment on Grace and Sevastano (2000). Journal of Experimental
Psychology: General, 129, 444–446.
Fantino, E., Preston, R. A., & Dunn, R. (1993). Delay reduction: Current
status. Journal of the Experimental Analysis of Behavior, 60, 159–169.
Fiske, S. T., Harris, L. T., & Cuddy, A. J. C. (2004). Why ordinary people
torture enemy prisoners. Science, 306, 1482–1483.
Geller, D. M. (1978). Involvement in role–playing simulations: A
demonstration with studies on obedience. Journal of Personality and
Social Psychology, 36, 219–235.
Harber, K. D., Zimbardo, P. G., & Boyd, J. N. (2003). Participant selfselection biases as a function of individual differences in time
perspective. Basic and Applied Social Psychology, 25, 255–264. Kamin,
L. J. (1956). Effects of termination of the CS and avoidance of the
US on avoidance learning. Journal of Comparative and Physiological
Psychology, 49, 420–424.
Michael, J. (1982). Distinguishing between discriminative and
motivational functions of stimuli. Journal of the Experimental
Analysis of Behavior, 37, 149–155.
Michael, J. (2000). Implications and refinements of the establishing
operation concept. Journal of Applied Behavior Analysis, 33, 401–410.
Milgram, S. (1963). Behavioral study of obedience. Journal of Abnormal
and Social Psychology, 67, 371–378.
Milgram, S. (1965a). Liberating effects of group pressure. Journal of
Personality and Social Psychology, 1, 127–134.
Milgram, S. (1965b). Some conditions of obedience and disobedience to
authority. Human Relations, 18, 57–76.
Milgram, S. (2004). Obedience to authority. New York: Perennial Classics.
(Original work published 1974) Mowrer, O. H. (1947). On the
dual nature of learning: A re-interpretation of “conditioning” and
“problem-solving.” Harvard Educational Review, 17, 102–148.
Navarick, D. J. (1982). Negative reinforcement and choice in humans.
Learning and Motivation, 13, 361–377.
Navarick, D. J. (1996). Choice in humans: Techniques for enhancing
sensitivity to reinforcement immediacy. The Psychological Record,
46, 539–554.
Navarick, D. J. (2001). Control of impulsive choice through biasing
instructions. The Psychological Record, 51, 549–560.
Navarick, D. J. (2004). Analysis of impulsive choice: Assessing effects
of implicit instructions. The Psychological Record, 54, 505–522.
Navarick, D. J. (2007). Attenuation and enhancement of compliance
with experimental demand characteristics. The Psychological Record,
57, 501–515.
Navarick, D. J., & Fantino, E. (1976). Self-control and general models
of choice. Journal of Experimental Psychology: Animal Behavior
Processes, 2, 75–87.
Orne, M. T. (1962). On the social psychology of the psychological
experiment: With particular reference to demand characteristics and
their implications. American Psychologist, 17, 776–783.
170
NAVARICK
Orne, M. T. (1970). Hypnosis, motivation, and the ecological validity of
the psychological experiment. In W. J. Arnold & M. M. Page (Eds.),
Nebraska symposium on motivation (pp. 187–265). Lincoln: University
of Nebraska Press.
Slater, M., Antley, A., Davison, A., Swapp, D., Guger, C., Barker, C.,
Pistrang, N., & Sanchez-Vives, M. V. (2006). A virtual reprise of
the Stanley Milgram experiments. PloS One, 1: e39. Retrieved August
18, 2008 from http://www.plosone.org/article/info:doi/10.1371/journal.
pone.0000039
Zimbardo, P. (2007). The Lucifer Effect: Understanding how good people turn
evil. New York: Random House.