Group Cognition PSY2002

What makes Group Decision making hard to study

Several methodological and conceptual challenges

Internal Cognitive Processes

Much of the reasoning happens during discussion and is not externally visible, making it hard to measure or replicate (Gigone & Hastie, 1997).

Coordination Dynamics

Variation in how group members coordinate their judgments, share information, or revise opinions complicates analysis.

Task Type

Performance differs depending on whether the task is:

Intellective (has a clear, correct answer) or

Judgement-based (requires estimation or opinion).

Individual Differences

Members differ in access to cues, memory ability, willingness to participate, or dominance in conversation.

Ecological Validity

Many lab studies involve small, artificial groups, which may not reflect real-world group settings (Newell et al., 2015).

When does the Wisdom of Crowds phenomenon occur

When the aggregate decision of a group outperforms that of most individuals.

Conditions for the Wisdom of Crowds phenom to hold

Diversity of opinion

Independence

Decentralisation - People must be free to draw on local, specialised knowledge.

Aggregation - There must be a mechanism (e.g., averaging) to combine individual inputs.

Breakdown of the phenom occurs when

Errors are correlated due to conformity or shared bias.

Groupthink or overconfidence takes hold (Janis, 1972).

There is too little or too much knowledge (e.g., recognition heuristic fails).

Factors that hinder group decision making

Groupthink

Polarisation

Overconfidence

Unequal Participation

Shared Biases

Coordination failure

Groupthink

Excessive cohesion leads to pressure for unanimity, suppressing dissent and critical evaluation. Results in poor decisions (e.g., Challenger disaster).

Polarisation

Group discussion can intensify initial opinions, moving decisions toward extremes.

Overconfidence

Groups may feel more certain than individuals, underestimating risks or alternatives.

Unqeual Participation

Dominant individuals may steer decisions, silencing diverse input.

Shared Biases

Correlated errors can undermine accuracy in estimation or judgment tasks.

Coordination Failure

Lack of clear roles, poor communication, or inefficient decision strategies disrupt consensus.

Argumentative theory of reasoning

Reasoning evolved to justify actions and persuade others, rather than to pursue truth in isolation.

Groups improve performance because they allow argument exchange, which enhances reasoning

Evidence for social accounts of reasoning

Individuals often fail the Wason selection task (~80% fail), but when discussed in groups, success rates rise to ~80%.

Discussion improves problem representation and encourages more abstract, accurate reasoning (Moshman & Geil, 1998).

Factors which enable and promote group decision making

Diversity

Social Sensitivity

Equal Participation

Task Clarity

Time and Discussion

Diversity

Brings a range of perspectives and cognitive styles.

Particularly effective in complex or ambiguous tasks.

But requires good coordination to avoid miscommunication or conflict.

Social Sensitivity

Groups with high average Theory of Mind scores (e.g., via the Reading the Mind in the Eyes Test) tend to have higher collective intelligence (Engel et al., 2014).

Equal Participation

Turn-taking and balanced input support better group performance.

Task Clarity

Groups perform better on intellective tasks with a known answer (Laughlin et al., 1991) than on judgment-based tasks.

Time and Discussion

Extended discussion allows correction of errors, weighting of reliable information, and revising opinions (Sniezek & Henry, 1990).

Features of an effective groyup

Leverage diversity, argument, and coordination to surpass individual reasoning.