DECISION MAKING
Chapter 10
Groups Decision Making
None of us alone is as smart as all of us
together (Myers, 2002)
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more people = more information
more people to do more work
more people means people can do what they
are best at
Groups Decision Making
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groups can discuss, process information
(check for errors, etc.)
groups have standards for deciding (e.g.,
majority rules)
people are more likely to follow through if
part of a group that decided
is not caused by any one mechanism,
but by several processes
Why make decisions in Groups?
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The effectiveness of groups as decision makers
 Examples: investment groups, advisory boards,
planners
 Individual vs. group decision making
– Majorie E. Shaw’s (1932) study of groups vs.
individuals
– Individuals solved fewer problems than groups
Type of Decisions
Group effectiveness also depends has a
demonstrated correct solution
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Intellective Tasks (right or wrong answer –
e.g., math problems ) vs. Judgmental Tasks
(no correct answer – jury’s verdict)
Group members are superior in intellective
tasks than judgment tasks.
Anatomy of Group Decision
Functional Theory of Group Decision Making
- Skilled decision making groups are more likely
use procedures that enhance the way they
gather, analyze, and weight information
Phases of Decision Making
- Orientation
- Discussion
- Decision
- Implementation
Orientation
Orientation
Defining the
Problem
Planning the
Process
Discussion
Functional Model of
Decision Making
No Decision
Reached
Decision
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Orientation

Decision
Reached
Implementation
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Development of shared
mental model
Group defines the problem
Sets strategy & goals
More time spent in this
stage the greater the
performance
Remembering
Information
Discussion
Exchanging
Information
Processing
Information
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Remembering Information – 30 % of all comments
made by group members are expressions of
opinions and analysis of issues
 Collective Memory – a group’s combined
memory
 Cross-cueing – recall of memories improved
through group members’ statements
 Transactive Memory – information is distributed
to various members of the group
Remembering
Information
Discussion
Exchanging
Information
Processing
Information
Weakness in group memory - importance of
keeping records (meeting minutes)
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Exchanging information: Acquiring & sharing data
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Processing information: Collective review of info.
Deciding
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Social Decision Schemes – strategy used
to select a single alternative from various
alternatives proposed by the group

Delegation - an individual or subgroup within
the group makes the decision for the group

Statistical Aggregation – group members’
individual decision are averaged
Deciding
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Social Decision Schemes
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Voting – publicly or secret ballot – 50% rule
is used primarily, however, sometimes more
substantial percentages are needed for a
decision to become final
Consensus (discussion to unanimity)
Random Choice – final decision is left to
chance
Implementation
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Implementation
 Evaluating the decision
 Adhering to the decision: Coch and French’s
(1948) clothing mill study
 Participation is key in decision making – if
limited, hostility, turnover, & satisfaction
decreases
Post-Mortem Discussions
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Bringing closure and learning lessons to bring to
future decisions
 Gather group together
 Review decisions made and decision making
process
 Look for lessons learned
 Record them
Individual vs. Group Decision
Making
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Vroom’s Normative Model of Decision Making:
theory of decision making that predicts the
effectiveness of decisional procedures across a
number of group settings

Autocratic I & II – leader solves the problem on
his/her own with information available at the time
or obtains information from group members and
then decides

Consultative I & II – leader either shares the
problem with selected group members or the
entire group
Individual vs. Group Decision
Making
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Vroom’s Normative Model of Decision Making:
 Group – the leader discusses the problem with
the members of the group. Together the leader
and members devise options for a solution.
 The leader acts as a chairperson of a committee
& does not try to influence the group to adopt a
certain a certain solution.
 Procedure must fit the problem to be solved and
the decision to be made
Group Discussion Pitfalls
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Group discussion pitfalls
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Information processing limitations: leveling,
assimilation, sharpening
Poor communication skills
Decisional avoidance (procrastination,
bolstering, avoiding responsibility, ignoring
alternatives, satisficing)
Shared Information Bias
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Is the tendency for groups to spend more time
discussing information that all members know and less
time examining information that only a few members
now
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Oversampling shared information leads to poorer
decisions when a hidden profile would be revealed
by considering the unshared information more
closely.
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Factors that increase (leadership style) and
decrease (using a Group Decision Support System)
the bias
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Judgment errors and heuristic biases
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Sins of omission and commission
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Sins of imprecision: Heuristics
Cognitive Limitations
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Judgment errors and heuristic biases – individual’s
judgments are often distorted by cognitive and motivational
biases
Individuals also overestimate their judgmental accuracy
because they remember all of the times their decisions were
confirmed
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Sins of omission – overlook useful information
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Sins of commission – information misused
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Heuristics – mental rules of thumb
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Sins of imprecision – oversimplify decision
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Confirmation Bias – tendency to seek out information that
confirms one’s inferences rather than disconfirms them
Group Polarization
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Group Polarization – the tendency to
respond in a more extreme way when
making a choice as part of a group, as
opposed to when responding individually
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Social comparison theory
Persuasive-arguments theory
“Risk-supported wins” social decision
scheme
Polarization and Risk
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Group Polarization: A shift in the direction of greater
extremity in individuals' responses
What is Groupthink?
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Janis’s theory of groupthink – a distorted style of
thinking that renders group members incapable of
making rational decisions.
Members try very hard to agree with one another
that they make mistakes that could easily be
avoided
 Example: Kennedy’s advisory group planning
the Bay of Pigs “covert op”
 The theory identifies symptoms, causes, and
possible cures
Symptoms of Groupthink
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Overestimation of the group (illusions of
invulnerability, illusions of morality)
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Close-mindedness (rationalizations, stereotypes
about the outgroup)
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Pressures toward uniformity (self-censorship, the
illusion of unanimity, direct pressure on
dissenters, self-appointed mindguards).
 Pluralistic ignorance and the Abilene Paradox
(Harvey, 1988)
 Entrapment and sunk costs
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Defective decision-making processes
Causes
Causes of Groupthink
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Cohesiveness
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Cordial relationships
Lack of conflict
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Structural Faults
 Insulation
 Control of the leader
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Provocative Situational Context
 How members deal with stress
 Exaggerate the positive and minimize the
negative
Can Groupthink Be Prevented?
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Limiting premature seeking of concurrence
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Open style of leadership
Devil’s advocate, subgroup discussions
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Correcting misperceptions and biases
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Using effective decision-making techniques