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THE BEHAVIORAL SUPPORT OF FOUR GROUP
DECISION PROCESSES: AN EXPERIMENTAL STUDY
OF INTRA-GROUP AGREEMENT AND INDIVIDUAL PREFERENCES
Carl H. Castore and J. Keith Murnighan
#303
College of Commerce and Business Administration
University of Illinois at Urbana-Champaign
FACULTY WORKING PAPERS
College of Commerce and Business Administration
University of Illinois at Urbana-Champaign
March 9, 1976
THE BEHAVIORAL SUPPORT OF FOUR GROUP
DECISION PROCESSES: AN EXPERIMENTAL STUDY
OF INTRA-GROUP AGREEMENT AND INDIVIDUAL PREFERENCES
Carl H. Castore and J. Keith Murnighan
#303
THE BEHAVIORAL SUPPO, T OF FOUR GROUP
DECISION PROCESSES: AN EXPERIMENTAL STUDY
OF INTRA-GROUP AGREEMENT AND INDIVIDUAL PREFERENCES*
by
Carl H. Castore J. Keith Murnighan
Purdue University University of Illinois
West Lafayette, Xnd. Urbana, Illinois
*This research was supported in part by a grant from the National
Science Foundation (No. GS27711) and in part by a contract
(No. N0001H-67-A-0226) from the Office of Naval Research, each
to the first author.
THE BEHAVIORAL SUPPORT OF FOUR GROUP DECISION
PROCESSES: AN EXPERIMENTAL STUDY OF
INTRA-GROUP AGREEMENT AND INDIVIDUAL PREFERENCES
by
Carl H. castors J. Keith Mumighan
Purdue University University of Illinois
Abstract
This research investigated the effects of four decision rules, majority
rule, dictatorship, unanimity, and consensus, of the behavioral support and
subjective rei ^tions of the group members following that decision. The
effects of two other variables, the amount of preference agreement among
the group members and the individual similarity of group members' preferences
to che group decision, were also investigated. The results for individuals'
subjective -reactions to the decision generally indicated that satisfaction
with and commitment to the decision increased as agreement within the group
increased and as an individual's preferences were more similar to his group's
decision. Ratings of difficu] ;y and changes in preferences were greatest
for groups which reached unanimous decisions. The result:;, for the behavioral
support of the decision indicated that the greatest support was evidenced
by groupr. with the greatest amounts of preference agreement and by group
meirbers v;A1ose individual preferences were most similar to the yro;.-p decision.
In addition, the unanimity and dictatorship groups showed remarkable
similarities in the amount of behavioral support evidenced at each level
of preference agreement. While the majority rule groups evidenced ligh
.aviorial support of the decision at all levels of preference agreement,
the consensus groups evidenced increasing amounts of behavioral support as
preference agreement increased.
Group Decisions
2
THE BEHAVIORAL SUPPORT OP POUR GROUP
DECISION PROCESSES: AN EXPERIMENTAL STUDY
OF INTRA-GROUP AGREEMENT AND INDIVIDUAL PREFERENCES
The present study investigated :he effects of three variables (i.e.,
the decision rule, the degree of agreement among the group members, and
the similarity of individual group member's preferences to the group
decision) on the group members' subjective reactions to their decision
and their behavioral support of that decision, While a major focus in
the previous research on groups has been group problem- solving (Davis,
1969), the present study distinguished between problem- solving, where
groups attempt to find a solution based on factual evidence, and decision-
making, where groups attempt to resolve disparities in opinion between
group members. Because decision-making groups often utilize facts, and
problem- solving groups often utilize opinions, there is some overlap
between problem- solving and decision-making. The present study, however,
has considered a task which is almost completely based on opinion and
therefore might be considered an investigation of "pure" decision-making.
Among the many variables which might affect both the decision which
is reached ?nd the effectiveness of chat decision are che decision rule,
the situation which the group faces, and the individual differences between
the group members. Bach of these three variables can have an impact on
almost any group decision, and the present study investigated each of them.
Although research on group decision rules began prior to World War II,
there are only a few utudias in the literature. Lewin, Lippitt, and White's
(1939) study comparing the effectiveness of majority rule, authoritarian,
and laissez-faire decision processes suggested that the superiority shown
by majority rule could be attributed to the increased participation and
involvement by group members in making the decision, tore recently,
Group Decisions
3
Harnett (1967) has shown that individuals will only resort to decision
processes other than strict majority rule when they cannot resolve their
differences using majority rule. These results imply that majority rule
is considered to be "fair", and that it is frequently the decision process
which groups use.
The study of social welfare and social choice, however, implies that,
under certain situations, majority rule may be clearly unfair. Research
on social choice centers around Arrow's (1951) classic conclusion, the
general possibiity theorems Given five reasonable conditions which one
must find in any general decision process, no single decision process can
be formulated to include all of the five conditions. There exists at
least one situation where each decision role will yield an inequitable
decision. This applies to the many forms of majority rule as well as
other decision schemes.
Although the work of the social choice theorists has not dealt with
effectiveness directly , the suspicion that a decision process which is
inequitable will also be ineffective is unavoidable (Cartwright and Zander,
1968) . Social choice theorists do imply, however, that decision processes
become inequitable when substantial disagreement exists within the group
(Black, 1958). Blake f Shepard, and Mcutcn (1964) support this point when
they suggest that maximally effective group functioning can only be
achieved when there is a total consensus among the group members on the
group's goal priorities and the decisions related to these goals. In
other words, as the diversity of members* preferences for different
operationalizable goals (March and Simon, 1958) increases, a group's
effectiveness will decrease. On the other hand, when the members of the
Group Decisions
4
group hold similar opinions or sirrdlar preferences, whatever decision
process a group uses will be equitable and the effectiveness of the group
will be relatively high.
The implications from social choice theory, then, lead to the
hypothesis that majority rule decision processes will be increasingly
equitable and increasingly effective as preference agreement among the
group members increases. In addition, the Lewis, et ral . , (1939) study
leads to a prediction that participative decision rules such as majority
rule are more effective than non-participative decision rules. These two
predictions can be combined into a single hypothesis: While the effectiveness
of majority rule decisions will vary positively with increasing agreement,
the effectiveness of non-participative decisions will remain unchanged as
preference agreement increases, relative to the majority rule decisions.
The third variable which was considered in the present study focused
on one of the individual differences between the members within each group.
While personality differences, for instance, may vary for different
groups, every group must deal with the fact that the individual preferences
of different group members will not be identical to the decision which the
group reaches. Indeed, group members whose own snces are more
similar to the group decision might be expected to be more supportive of
that decision (Hackman and Morris, 1975). Coleman (1966) has also suggested
that the support that an individual accords a group decision, given no
coercion, is in large part dependent upon the correspondence between his
personal goals and those of the group, as reflected in its decision.
In addition, social comparison theory (Festinger, 1954) suggests that, to
the extent than an individual views himself as a part of the dominant
Group Decisions
5
majority within a group, he will be relatively satisfied with the outcomes
of the group decision and will be relatively supportive of th
Alternatively, to the extent that an individu; < self as a
relatively uninfluential member within a gr< be relatively
dissatisfied with the outcomes of coup decision process, regardless
of the absolute level of satisfaction he feels.
A previous study (Castore, 1973) examined two of the variables
investigated in the present research: the level of overall agreement on
goal priorities within a group and the similarity between an individual's
goals and the goal established, by his group's decision. Four-person
groups used the method of elimination (Black, 1958, p. 217) , a form of
majority rule, to make their decisions. The results showed that the
level of overall agreement within the group significantly influenced all
of the affective responses. As predicted, there were higher ratings of
commitment, satisfaction and representativeness and lower ratings. of
difficulty with higher levels of agreement. In addition, the degree of
preference agr ement within the group ignificantly inf li 2nced the behavioral
support shown by group members s the least behavioral support for the
group's decision was found in the ersity conditions. The
degree of relative similarity between a and the goals
established by the group decision also resulted in positive (and significant)
effects on the individuals' ratings of satisfaction and their behcivioral
support of the group decision. It is interesting to note that post hoc
analysis of the significant effect for behavioral support indicated that
the individual whose preferences were most similar to the group decision
showed less support than the individual whose preferences were the second
Group Decisions
6
most similar to the group decision. The other group members showed
significantly less support than either of these two sets of individuals.
The pre&^nt study, then, extended this research to three other
decision processes, increased the rather small sample size of the previous
study, and utilized five-person rather than four-person groups to ramove
the possiblity of a stalemate between two pairs within the group.
Method
Subjects. The subjects in this study were 200 male volunteers
enrolled in introductory psychology at a large midwestern university. All
subjects appeared in response to an advertisement promising a free 33 1/3 LP
record album and credit toward a course requirement of participating in
experiments. It was made clear to all subjects prior to their actual
participation that the exact LP album they would receive would depend
upon the decisions reached by their particular group.
Task. The group decision task used in the first portion of the
experiment was chosen to simulate conditions which are present when
individuals ir a group must reconcile conflicting priorities for alternative
operationalizable goals. The decision task required the group members to
rank a set of five LP record albums, using one of the four decision rules.
The subjects were free to discuss their preferences as long as they wished.
They were informed that the group ranking would (in part) determine the
album each of them would receive for their participation, in the following
manner: The group ranking would be used to establish a lottery such that
the first choice of the group would have a 35% chance of being the album
all received; the second choice, a 30% chance; the third choice, a 20%
chance; the fourth choice, 15% chance; and the fifth choice, a 0% chance.
Group Decisions
7
As a reminder to the subjects, these probabilities were posted on a
blackboard on the wall of their group room.
Following the ranking, each group member completed four scales
(0-100 graphic rating scales) describing his reactions to the group
decision in terms of: (a_) how satisfied he personally was with the
ranking; (b) how fairly he thought it represented the preferences of
the group as a whole; (£> how committed he would be to the group decision
if he had to defend it; i.e., how strongly he would support it; and
(d) how much difficulty he thought his group had experienced in reaching
the decision. In addition, the subjects also indicated the proportion
of influence they thought each of the members of their group, including
themselves, had on the group decision. This latter question formed the
basis of two variables in the analysis: (a) the average amount of
influence on the group decision attributed to an individual by his
associates in his group; and (b) the relative amount of influence an
individual saw himself as having on the group decision process.
The second portion of the experiment was a bargaining
situation. Each subject was placed ir. a situation where the possibility
of coercive pressure from the other group members was minimal, allowing
for measurement of the extent to which an individual independently
supported his group's decision. Because two groups made their rankings
of the same set of five record albums at the same time, each group member
could be paired with a member of the other group. Individuals were
instructed to act as a representative of their group in their negotiation
with a member of the other group. The result of the five negotiations were
up Decisions
8
five rankings of the LP albums. Then, the subjects -/ere informed that
their negotiated solution? \ be weighted as h heir gz
decision in determining the lotter select th group
members would receive,. An individual avioral support of his grov
decision was calculati naan R
between his negotiated ranking and his group's tanking of the LP albums.
Procedures. All potential i . were given a number of five
album sets of LP records to rank one week prior to participation in
the experiment. The rankings of the albums within each of these sets
provided the basis for scheduling individuals into groups such that eight
five-person groups were formed having indices of concordance (W) between
.00 and ,20, between .20 and ,40, between .40 and ,60? between .60 and
.80, and between .80 and 1.00, for a total of 40 five-person groups (two
groups under each decision rule at each level of concordance) .
Upon arrival at the experiment, the group decision task and the
lottery were explained to the subjects and any questions they had were
answered. The group discussions were hegur after it was clear that
all group members understood the mechanics of the lottery. After the
group decision was reached, the group members we parated within their
group rooms and administered the scales which were ussd to record the
impressions of the group decisions and s influence that each
had on the decision.
After the rating forms had been completed, the dyadic negotiations
task was presented to the subjects. At this point, the manner in which
their individual solutions would be added to their group's decision to
make up the actual lottery was explained. The subjects' only instructions
Group Decisions
9
for the negotiation task were "to act as a repres< .ve of your c-
If there were any questions from t .ts about whether they tfere to
act in their own in1 their sst, the experimenters
simply reiterated that they were to "act as a representative mr group. j!
Following these instructions, the it random to
dyads and these dyads were seated in rooms to conduct their
negotiations.
Aftex the negotiations were completed f the lotteries were constructed
and the drawings held to determine the record the group members would
receive.
Desigji. The overall design for the experiment was a 5 (group
concordance) X 4 (relative correspondence between an individuals goal
preferences and the decision of his group; X 4 (decision schemes) factor:
design. The level of overall group agreement on goal priorities was
operationalized in terms of Kend- >f Concordance e W
(Kendall, 1943). The value of W was calculated for a group on the basis
of the individuals5 preference orderings of the available outcomes expressed
prior to their partic Latent. Subjects we
preselected and asi to group -person groups
were formed at each of five < W < .20;
(2) . W < .40; (3) .40 < W < .60; {4 ■ .80 < W < 1.00,
Within each of these levels the e ■• attempted to form groups
with the lowest concordance values poss
The relative correspondence between an individual's preferences and
the decision reached by his group was opera tionaiised by ranking the five
persons in each group , one through five, in terms of the similarity between
up I
10
their Initial preference ranking c alternatives and that arrived at
by the group (calculated as :n Pho rank cor: Ion, Peatman ,
1963).
Pour different group decisi ss were major ule,
dictatorship* unanimity, at lajority rule were
instructed to begin by cho
discussion, to vote between, them., as to be
paired next with one of tiing alternatives. Sequential pairings
of this sort continued until one of the aitem ■ s the
group's first choice. The remaining alternatives were selected, discuss
and voted upon in the same manner until the second , third, fourth* and
fifth choices were determined. In the unanimity conditions, any group
member could keep the discussion open as long as he desired until
decision which ranked the five alternatives was unanimously accepted.
One subject in each dictatorship group was randomly designated as I
"decision maker" for that group. The other group members were told that
they could present arguments in favoi personal preferences,
but the final decision depended solely In the
consensus condition, subjects were told to discuss the five alternatives
and arrive at a consensus about t & given no formal
procedure to arrive at ranki
Re-
Eight dependent variables were considered, within the framework of
the present study. Four of these variables (i.e., rated satisfaction,
commitment, difficulty, and representativeness) were taken from the
Group Decisions
11
subjects' responses on the IOC—point graphic rating Two of tl
variables were derived from the proporl e the subjects
attributed to the o of th luding sives) . The
seventh measure in the analys Ls M ent to wn lual
chanced his preferei Ion* Th
was calculated as a pa she indi
initial preference ai group - hange in the
individual's post decision preference
Percentage 1 .hange
00 - initial
where final is the Spearman rar- /.'elation between an individual's final
preference ranking and his group's decision and initial is the corresponding
correlation for an individual's preference ranking prior to the group
discussion, The final variable in the analysis was the previously
described measure of behavioral support of the group decision.
Dec isig :n_Rul es . Each dependent variable was analyzed in separate
analyses of variance. The me decision rule
for each of the dependent variables wh ch ... - v ficant differences
are shown in Table 1. Rated satisfa ed representativeness, and the
Insert Tb
two influ Measures did not evl Lsion rule main
effects. The results for ra1 Lty and for preference change are
not surprising; unanimi rcoups t was store difficult to reach
their decision than the other groups and members of these groups changed
their preferences more than members of other groups.
Group Decisions
12
The results for behavioral support generally agree with the predictions
derived from group dynamics research: participative decision rules (majority
rule, unanimity, and consensus) result in greater support than non-partici-
pative decision rules (e.g., dictatorship). However, the corresponding
ratings of commitment, which were expected to closely parallel the
behavioral support data (Fishbein and Ajzen, 1972) , showed that members
of the majority rule groups felt that they would be less committed than
members of the other groups. This unexpected result may be explained by
the fact that the members of the majority rule groups were constrained
by a very formal decision process, one that resulted in very little
group discussion. Instead of discussing their preferences, group members
merely voted on each pair of alternatives as they were presented. As
a result, there was little chance for the development of the group
cohesiveness which the group dynamics literature indicates is crucial
in participative decision processes. Participation, which in these
groups meant merely voting, may not be sufficient by itself to generate
commitment by group members. Participation through discussion may be the
crucial determinant.
Preference Agreement. All four ratings (other than the influence
ratings) revealed significant differences for overall agreement of
preference within the group (see Table 2) . The means for the four ratings
Insert Table 2 about here
and for behavioral support indicate that group members with the most overall
Group Decisions
13
preference agreement reacted most positively to the decision and the
decision process: (1) they rated themselves as the most committed to
and the most satisfied with their decision; (2) they rated their decision
as the most representative and least difficult; and (3) they showed the
xnost behavioral support for their groups' decisions. However, the
converse was not true for the groups with the least intra-group preference
agreement. Rather, the members of the groups in the second lowest agree-
ment level evidenced the least behavioral support, the lowest commitment,
satisfaction, and representativeness ratings, and the highest difficulty
ratings. Observations by the experimenters provided a possible explanation
for these results. Many subjects in each of the conditions voiced an
opinion prior to the group discussion that the experimenters would
probably be making the decision as difficult as possible by constructing
groups with members whose preferences were extremely diverse. In the
lowest concordance groups many subjects found that this prediction was
correct. Instead of engaging in verbal conflict, however, many of these
individuals responded by attempting to avoid conflict. A spirit of
compromise often became apparent. Because they recognized their plight,
the subjects in the lowest concox-dance groups "made the best of it" and
were not as frustrated as one might have expected. Members in the other
groups, however, were not so fortunate. At the other concordance levels,
each group member was generally able to find at least one other group
member whose preferences resembled his own. However, particularly in the
second lowest concordance groups, there were rarely more than two group
members who held similar preferences. Thus, with only a minority of the
group agreeing with each other, individuals in these groups became quite
frustrated and responded with negative ratings and low behavioral support
of their decision relative to the responses of the members of other groups.
Group Decisions
14
Relative Similarity to the Group Decision. The means for the
significant main effects for relative similarity to the group decision
are shown in Table 3. Although the main effects for rated difficulty
and rated representativeness were not significant, the findings for the
Insert Table 3 about here
other dependent variables indicate that the least similar group members
rated themselves as less committed, less satisfied, and less influential
than other group members. They also evidenced the most preference change
and the least behavioral support of the group decision than other group
members. Similarly, the most similar group members had the highest
commitment, satisfaction, and influence ratings and evidenced the least
amount of preference change and the most behavioral support. The expec-
tations for the other group members were also supported: in general, the
more similar an individual's preferences were to the group decision,
relative to the other members of his group, the more positively he
responded. The only exception to this pattern occurred for the two
influence ratings. The means for these variables reveal that the second
most similar group member received lower influence ratings than the
third most similar group member. These differences, however, were not
significant.
The Decision Rule - Preference Agreement Interaction. Of all the
analyses which were conducted, only one resulted in a significant interaction,
between the decision process and the overall preference agreement within the
group for behavioral support of the group decision (see Table 4) . Post hoc
Group Decisions
15
analysis revealed that there were only minor , unsystematic changes in the
Insert Table 4 about here
behevioral support of majority rule decisions as a function of agreement
within the group. However, there were systematic changes in the behavioral
support of dictatorial, unanimous, and consensual decisions as a function
of overall agreement. In particular, both unanimity and dictatorship
groups evidenced extremely low behavioral support of the decisions reached
in the second lowest concordance groups, while consensus groups evidenced
increasing behavioral support of the group decision as overall agreement
increased .
The Ubiquity of Majority Rule. The final analysis concerned the
similarity of the groups' decisions in each of the conditions to a decision
which would be predicted by the application of a majority rule decision
model to the group member's individual preferences prior to their decision.
The majority rule model which considers each possible pairing of the
alternatives is the 3ame process which the majority rule groups used to
make their decision. However, instead of selecting two alternatives at
random for the first vote, each of the possible pairings of the alternatives
is considered. This technique will detect any cyclical majority (Arrow,
1351 ) which might be present, even though the groups themselves (even the
majority rule groups) may not have been able to detect them.
A 4 (decision rules) by 5 (concordance levels) analysis of variance
was conducted, then, for the Spearman rank, correlation between the actual
Group Decisions
16
group decision and the prediction of the majority rule model. The fact
that groups was the unit of analysis and there were only two groups in
each cell resulted in a small N, whicn in turn reduced che power of the
teat. The results, therefore, should be viewed with caution. The analysis
did result in a significant effect for overall preference agreement within
the group (F{4,20) - 3.70, £ <.021). The main effect for decision rule
and the interaction were not significant (the F_~ratio was less than 1.00
in each case), , The different decision processes, therefore, resulted
in decisions which did not differ in their similarity to the predictions
of the majority rule model. In addition, post hoc tests of the significant
main effect revealed that there was less correspondence between the
majority rule model's prediction and the actual group decision in the
lowest agreement groups (X = .42) than there was in the highest agreement
groups (X « .90). None of the other values were significantly different
from one another.
Discussion
In general, these findings support the results reported earlier
by Castore (1973) . Higher levels of overall agreement and greater
similarity to the group decision resulted in more positive affective
and behavioral responses. The inclusion of four decision rules yielded
several additional findings, indicating that certain participative
decision rules resulted in greater behavioral support of group decisions
and more positive affective responses than non-participative decision
rules.
Group Decisions
17
There were several surprising results within the pattern of results
indicated by the interaction between decision rule and agreement within
the group. Groups employing unanimity as a decision rule did not show
a great deal of support for their decisions, especially in the second
lowest agreement condition. Only in one condition for the dictatorship
groups was there lower behavioral support. One observation that explains
this result is that a group which must use unanimity as its decision rule
proceeds not with a single dictator, as in the dictatorship groups, but
with five dictators. Certainly, the results for the unanimity and
dictatorship groups are surprisingly similar and give some support for
this explanation.
The consensus groups exhibited the varying behavioral support
which social choice theory predicted for the participative decision
rules. As overall agreement increased, so did the behavioral support
of the group members . The majority rule groups, on the other hand,
exhibited the relatively constant, high behavioral support which was
predicted by the Lewin, et al, (1939) research. This does not, however,
correspond to Castore's (1973) findings, which showed that behavioral
support increased as agreement increased. This discrepancy may be the
direct result of the difference in group size between the present and
Castore's study. Because there were an even number of group members
(n - 4) in that study, the groups often faced situations where the vote
was deadlocked, two against two. It is interesting to note that, with
four-person groups, a simple majority becomes a three/fourths majority
because three votes are needed to attain a majority. Thus, if the number
Group Decisions
18
of members within the group is even, the probability of deadlocks increases,
and groups using a formal majority rule decision process may have difficulty
in reaching a majority. Given this dependence on whether the group size is
odd or even, the findings from the groups in the Casio re {1973} study might
be expected to coincide with findings for a five-person group which must
attain a four/fifths majority- Compared to the present study, the
results might be expected to fall somewhere between the results of the
majority rule and unanimity five-person groups. Because of the extreme
nature of the results in the present unanimity groups, the exact correspondence
of the two sets of data is impossible to ascertain. However, the data from
the two studies do suggest that increases in the size of the majority
necessary to reach a decision may result in corresponding decreases in
behavioral support of the group decision when substantial disagreement
within the group exists. Further research in this area is clearly indicated.
The interaction can be dissected even further. Blocking out the
lowest agreement conditions from the data in Table 4 would tend to support
the Lewin, e* al (1939) prediction f<~>r the consensus groups as well as
the majority rule groups and might lead one to classify unanimity in a
category apart from these, closer to autocratic decision processes.
In addition, for the highest three agreement levels, the behavioral
support evidenced by the group members, regardless of the decision rule
they used, was relatively high. It seems , then, that when there is little
difference of opinion, even a dictator may be able to expect support for
his decisions.
The results for preference change also warrant some discussion* There
were significant main effects for decision rule and for individual similarity
to the group decision for the percentage change in the preference of
Group Decisi
19
individuals from the beginning to the end of the experiment. Intervening
between the two measures was a group decision process and a negotiation
exercise for each individual. Both ttay hav< fluenced the change.
Nevertheless, the fact t'- - airnity groups evidenced
more change in their preferences than groups ter decision rules
leads to the proposition that more difficult decision processes may lead
to increased preference change by the group mei effect
which showed thai Individuals whose preferences were least similar to
the group changed their preferences most also supports the theory of social
communication (Festinger, 1950) , which states that communication will be
directed toward those whose individual goals differ from the goals of the
group .
&n analysis of the similarity between the actual decision reached
and a decision reached by a majority rule model (Murnighan, notes 1 and 2}
showed that in all of the decision rule conditions the final decisions
were quite close to the predictions of the majority rule model. In
essence , then? the preferences of the members of each of the groups,
regardless of the decision process tl re instructed to use, were
equally considered in arriving at the group dscis , Although in
some cases the imposition of a different decision rule may have altered
the group's final decision, this finding suggests that the alterations
were relatively minor. The data also support : Lett's finding, in
that, regardless of the decision rule prescribed, the groups' decisions
were a result of a process approximating majority rule. In addition, the
conclusion that the decision, itself has only a portion of the impact on
the post-decision behavior of the group members is unavoidable. The
group members' perceptions of their decision process seems to have a
Group Decisions
20
decided impact on their affective responses toward that decision and the
degree of their subseque. b for it.
Group Decisions
21
Reference Notes
1. Murnighan, J. K, Coalition behavior in decision making groups.
Unpublished doctoral dissertation. Department of Psychological
Sciences, Purdue University, 1974.
2. Murnighan, J. K. A study of coalition behavior in decision making
groups. Working paper #260, College of Commerce and Business
Administration, University of Illinois, 1975.
Group Decisions
22
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Blake, R. R. , Shepard, H. A., and Mouton, J. S. Managing Human Conflict
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Cartwright, D. , and Zander, A. Group Dynamics. New York, N.Y.: Harper
and Row, 1968.
Castore, C. H. Diversity of group member preferences and commitment to
group decisions. Annals of the New York Academy of Sciences, 197.3,
219, 125-136.
Coleman, J. S. Foundations for a theory of collective decisions.
American Journal of Sociology , 1966, 71, 615-627.
Davis, J. H. Group Performance. Reading, Mass.: Addison-Wesley, 1969.
Festinger, L. A. Informal social communication. Psychological Review ,
1950, _57, 271-282.
Festinger, L. A. A theory of social comparison processes. Human Relations ,
1954, 7, 117-140.
Fishbein, M. , and Ajzen, I. Attitudes and opinions, Annual Review of
Psychology , 1972, 23, 487-544,
Hackman, J. R. , and Morris, C. G. Group tasks, group interaction
process, and group performance effectiveness: a review and proposed
integration. In L. Berkowitz (Ed.), Advances In Experimental
Social Psychology, vol. 8, 1975,
Harnett, D. L. A level of aspiration model for group decision making.
journal o_f Personality and Social Psychology ? 1967, 5_, 58-66.
Group Decisions
23
Kendall, M. G. The Advan statistics. Philadelphia, Pa.:
.J. B. o,f 1943.
Levin, K. , Lippitt, R White, R. Patterns of a we behavior
in. expe Journal acial
Psycho 1 - 271-299,
March, J. an; H. A. J-ey and
Sons, Co. , 1958.
Peatman, J. G. I ion t- v'ork, N.Y.:
Harper and Row, ¥.■■
Winer, B.J. Statistical Principles in E u. Design. New York,
N.Y.j McGraw-Hill, 1962.
Group Decisions
24
Footnote
1. Arrow's five conditions can be iraaarized as:
(1) In groups with at least t duals facing at least three
alternatives, all individual orderir. the alternatives are
permissible.
(2) A social choice function asserts that an alternative x
is preferred to an alternative y will also assert a preference
for x when, in any comparison between x and other alternatives,
preferences for x remain unchanged or are zoodified in x's favor,
(3) If a social choice function asserts that x is preferred to y,
it will also assert that x is preferred to y if an additional
alternative z is included in the choice function, even though
z may or may not be preferred to x and/or y.
(4) For each pair of alternatives x and y, there is some profile of
individual orderings such that society prefers x to y.
(5) There is no individual who can determine society's preferences,
regardless of the orderings of the individuals in that society.
Group Decisions
25
SLi 1
A Summary of the Analyses and the Means for Each Dependent
Variable Which Resulted in a Significant Main Effect for Decision Rule
Dependent
Variable
Rated
Commitment
Rated
Difficulty
Percentage
Preference
Change
Behavioral
Support
Majority
Rule
70.9,
15,4
b
26.8
.806
a
Dictator-
77.4
21.
2.7.2
.558
c
Decision Rule
Unanimi Consensus
79.1
34.0
.662,
79.0
18.. 9.
43,8, 29.0
d a
.730
^
p*
2.90
6.40
2.62
9.92
P<
.038
. COOS
.055
. 0001
*df « 3,100
Note : The effects for rated satisfaction, representativeness, and influence were not
significant. Cells sharing a common subscript, within the levels of each dependent
variable, are not significantly different from one another at the .05 level using
the planned comparisons procedure (Winer, 1962
TABLE 2
A Summary of the Analyses and the Means for Each Dependent Variable Which Resulted in a
Significant Main Effect for Overall Agreement
Dependent . 00- . 19
Variable
Overall Agreement (Concordance)
20-. 39 .40-. 59 .60.-79 .80-1.00 F*
P<
Rated
Commitment
74.
02
Rated
Difficulty
21.
52
Rated
Satis-
74.
25
faction
Rated
Represent-
ativeness
81.
55
be
be
be
Behavioral
Support •630.
68.17 75.72,, 80.52 . 84.62 6.07
c b ab a
34.17 22.67,. 21.70,. 12.42 4.68
a b be c
64. 85^ 73.47 _ 82.95 . 86.52 7.17
d cd ab a
70.70,. 83.57 82.37 84.25 4.65
b a a a
.512
.715,
0004
002
,0001
.710,
.877 12.75
a
003
00005
Mf - 4,100
Note: The effects for influence and preference change were not significant. Cells
sharing a common subscript, within the levels of each dependent variable, are not
significantly different from one another at the .05 level using the planned comparisons
procedure (Winer, 1962) .
TABLE 3
A Sugary of the Analyses and the Means tor Each Dependent Variable Which Resulted in a
Significant Main Effect for Relative Similarity to the Group Decision
Dependent Most
Variable Similar
Rated
Commitment 85.85
Rated
Satis-
faction
87.52
Ratings of
One '' s Own
Influence 21.72
Otters'
&at i ngs
Cnflu-
ence
Percentage
Preference
Change
Behavioral
Support
21.55
.14,3
.757
ab
^£j^iye_S i^^r i ty
2nd Most 3rd Mi
Similar Similar
79.2:
ab
79.07
19.2'
ab
76,
jD
81.40
a
22.80
iar
1 . -
71.07,
DC
iA. O a \J* -^/
■±
■lar
66,27
97
16,62,
19.52
abc
22.9
be
690
22.15
38.5 .
ao
19.20
be
42.1
] 8 . 4 7
40.5
sib
68"
ab
,677
ab
.632
b
p*
7.72
8.94
27
2.74
4.84
1.43
P<
.0001
.00005
.07
.05
.002
25
*df - 4,100
Note: The .effects for rated difficulty and. representativeness were not significant.
Cells sharing a common subscript, within the levels of each dependent variable, are
not significantly different from one another at the .05 level using the planned
comparisons procedure (Winer, 1962).
Group Decisions
28
TABLE 4
A Summary of the Analyses and the Means .or the Significant (F (12, 100) = 4.73,
? < .00005) Interaction Between Decision Rule and Overall Agreement for Behavioral Support
Decision
Rule
Majority
Rule
Dictator-
snip
00- - 19
780
ab
570,
Unanimity . 730
nsensus .440
Overall Agreement . _ (Concordance : )
20-. 39 .40-. 59 .6 ,80-1.00
850
160
360
680,
700,
880
,820
ab
660
ab
,600
ab
.800
a
680,
b
540, 1.00
oc a
820
ab
820
ah
.890
2.21
8.99
7,03
6.81
P<
09
,0001
.0003
,0004
FThe F values were calculated for each decision rule separately. Degrees of freedom
in each case were 4 and 4c;.
Kote : Cells sharing a common subscript within each decision rule are not significantly
different from one anoti er at the .05 level usi g the planned comj arisons procedure
(Winer, 1S62) .
t\Y
r-94
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