11
Decision
Making
People turn to groups when they
must solve problems and make
decisions. Groups often make
better decisions than individuals,
for groups can process more
information more thoroughly. But
groups, like individuals,
sometimes make mistakes. When
a group sacrifices rationality in its
pursuit of unity, the decisions it
makes can yield calamitous
consequences.
 How do groups make
decisions?
 What problems undermine
the effectiveness of decision making in groups?
 Why do groups make
riskier decisions than
individuals?
 What is groupthink, and
how can it be prevented?
Functional
Perspective
Orientation
Stage
Discussion
Stage
Decision
Stage
Implementation Stage
Who
Decides?
Problems
and Pitfalls
Planning to
Fail
The Difficulty
of Discussion
The Shared
Information
Bias
Cognitive
Limitations
Dysfunctional
Post-decision
Processes
Group
Polarization
Decisions
Involving Risk
What Causes
Group
Polarization?
The
Consequences
of Polarization
Groupthink
Symptoms of
Groupthink
Defective
Decision
Making
Causes of
Groupthink
Emergence
of
Groupthink
Alternative
Models
Preventing
Groupthink
The mob has
no judgment,
no discretion,
no direction,
no discrimination, no
consistency.
Cicero
Madness is the
exception in
individuals but the
rule in groups.
Nietzsche
When "a 100 clever
heads join a group,
one big nincompoop
is the result.”
Carl Jung
Decision Making in Groups
Making Decisions in Groups: The Pluses and Minuses
Why Use Groups?
Why Not Use Groups?
 more people = more information
 sometimes the group doesn't
recognize the correct answer, even
if proposed
 more people to do more work
 more people means people can do
what they are best at
 groups oversample shared
information
 groups can discuss, process
information (check for errors, etc.)
 sometimes work done by just a
few (social loafing)
 groups have standards for deciding
(e.g., majority rules)
 discussion can be manipulated
 people are more likely to follow
through if part of a group that
decided
 groups sometimes make riskier
decisions
 groups sometimes suffer from
groupthink
Functional
Perspective
The ODDI Functional Model of
Decision Making
Functional
Perspective
Orientation:
• identifying the problem, setting goals
• planning the process
• developing a shared mental model
Groups are tempted to bypass
this stage, but time spent in
orientation improves:
• collaboration among members
• time management
Functional
Perspective
Discussion:
•
•
•
•
improved memory
exchange of information
processing of information
error detection
Collective memory processes
• combined individual memories
• cross-cueing
• transactive memory
The key to effective group decision making is the quality of group’s
discussion
Bales’s observations
indicate that groups
spend the majority of
the time during the
discussion dealing
with suggestions,
expressing opinions,
and developing a
shared orientation to
the task.
Functional
Perspective
Delegation
Averaging:
Statistical
“Crowdsourcing”
as averaging
aggregation
(statistical aggregation)
Voting
Consensus (discussion to
unanimity)
Random choice
Social Decision Schemes: How
Groups Make Choices
Functional
Perspective
Implementation:
• Distributive justice
• Procedural justice
Participation effects are strong
• Coch & French verified the “voice”
effect
• More participation means better
engagement in implementation
Who
Functional
Decides?
Perspective
Vroom’s Model of
Decision Making
Consult
(Individual):
Decide:
Leader
makes
decision
Leader
discusses
with
individual
members,
then makes
decision him
or herself
Consult
(Group):
Leader
discusses
with group,
but makes
decision
him or
herself
Facilitate:
Leader
coordinates
problem
solving
session
Delegate:
Leader
turns
problem
over to the
group
Functional
Perspective
Orientation
Stage
Discussion
Stage
Decision
Stage
Implementation Stage
Who
Decides?
Problems
Group’s are Group
prone to the
planning
Groupthink
and Pitfalls Polarization
fallacy
Planning to
70 Fail
60
The Difficulty
50
of Discussion
40
30
The Shared
20
Information
10 Bias
0
Cognitive
Limitations
Individuals
Group
Actual
Dysfunctional
Post-decision
Individuals underestimated the time they would
Processes
need for each phase of the task (planning, analysis,
etc.), but groups’ estimates were even less accurate
than individual’s.
The Difficulty of Discussion
Discussion can be
challenging:
• Poor discussion skills
• Meetings (death by…)
• Wasted time (law of
triviality)
• Muddling through
Discussion is rarely equal: most group members’ voices are not heard
50
Size of Group
45
3-person
40
4-person
5-person
35
Percentage
6-person
30
7-person
8-person
25
20
15
10
5
0
1
2
3
4
5
6
7
8
The Shared
Information
Bias
Oversampling
shared
information
leads to poorer
decisions when
a hidden profile
would be
revealed by
considering the
unshared
information
more closely
Causes
Informational influence
 Normative influence
 Emphasis on consensus vs.
correctness
 Initial preferences
 Impression management goals

Reducing the Shared Information Bias
The SIB can be
reduced by
improving
information
exchange by:
60
50
40
F-to-F
GDSS
30
Good leadership
 Increasing
diversity
 Using a GDSS
(group decision support system)

20
10
0
Pre
Post
Discussion
Cognitive Limitations
Type of Error
Sins of Commission
Sins of Omission
Sins of Imprecision
Cognitive Limitations
Type of Error
Sins of Commission
Sins of Omission
Sins of Imprecision
Dysfunctional Postdecision Processes
Denials of
Groups do not systematically check their work. Instead, they
defend their choices, seeking reassurance rather than
effectiveness.
Responsibility
Abilene
Paradox
Entrapment
(sunk costs)
Functional
Perspective
Problems
Group
Groups are
not more cautious
than
Groupthink
and Pitfalls
Polarization
individuals:
They tend to be riskier!
Decisions
Involving Risk
What Causes
Group
Polarization?
The
Consequences
of Polarization
The Risky Shift
Effect
Decisions
Involving Risk
Polarization and Risk
Group polarization: A shift in the direction of
greater extremity in individuals' responses
What Causes
Group
Polarization?
Social
comparison
theory
Persuasivearguments
theory
Social
identity
theory
Risk and Caution are
Cultural Values
American’s predeliberation
judgments
American’s postdeliberation
judgments
Chinese’s predeliberation
judgments
Chinese’s postdeliberation
judgments
Functional
Perspective
Problems
and Pitfalls
Group
Polarization Groupthink
Symptoms of
Groupthink
Defective
Decision
Making
Causes of
Groupthink
Emergence
of
Groupthink
Alternative
Models
Preventing
Groupthink
Symptoms of
Groupthink
IIrving Janis, in his
book Victims of
Groupthink, used
case study methods
to identify the factors
that combine to cause
a group to make a
disastrous decision.
Defective
Decision
Making
Causes of
Groupthink
Research
suggests
groupthink
becomes most
likely when
cohesion is
combined with
one or more
other causal
factors.
Emergence
of
Groupthink
Janis
suggested
that
groupthink
occurs only
in cohesive
groups—
less
cohesive
groups can
make bad
decisions,
but they
cannot
experience
groupthink.
Alternative
Models
Group-centrism: the tendency for groups tend to rush to make
judgments on the basis of insufficient information, particularly if they
face situations that interfere with their capacity to process
information—time pressures, severe ambiguity, noise, or fatigue
(Kruglanski 2006).
Ubiquity model: groups commonly groups often strive for
consensus and that, in doing so, they tend to limit dissent, denigrate
the outgroup, and misjudge their own group’s competence, and these
tendencies undermine decision making when
• Failure would threat the group’s social identity
• Norms constrain open communication
• Members lack self-confidence (Baron, 2005)
Preventing
Groupthink
Janis suggests that,
rather than limiting
cohesion, groups
take alternative
steps to minimize
the possibility of
groupthink.
Limiting premature seeking of
concurrence
• Open style of leadership
• Devil’s advocate,
subgroup discussions
Correcting misperceptions
and biases
Using effective decisionmaking techniques
Functional
Perspective
Orientation
Stage
Discussion
Stage
Decision
Stage
Implementation Stage
Who
Decides?
Problems
and Pitfalls
Planning to
Fail
The Difficulty
of Discussion
The Shared
Information
Bias
Cognitive
Limitations
Dysfunctional
Post-decision
Processes
Group
Polarization
Decisions
Involving Risk
What Causes
Group
Polarization?
The
Consequences
of Polarization
Groupthink
Symptoms of
Groupthink
Defective
Decision
Making
Causes of
Groupthink
Emergence
of
Groupthink
Alternative
Models
Preventing
Groupthink