Groups

Video Clip 2: Reginald Denny

Outline

Why we live in groups Social facilitation Social loafing Group decision making

• Best reliable predictor of brain size in primates is social group size

• Human beings are adapted to live in social groups

• All primates except ourangutans

Benefits of group living

Protection from predation and from intergroup conflict

Collective hunting of big game & coordinated food gathering

Cultural learning

Social exclusion is painful Eisenberger, Lieberman, & Williams (2003)

Virtual ball-tossing game Inclusion vs. exclusion rounds fMRI scan dorsal anterior cingulate cortex (dACC)

Social exclusion is painful Eisenberger, Lieberman, & Williams (2003)

Greater activation of dorsal anterior cingulate cortex (dACC) when excluded

Excluded subjects who reported being more upset showed greater activation of dACC

Human sensitivity to social exclusion Physical pain = social pain

The Nature and Purpose of Group Living

Group - A collection of individuals that have relations to one another that make them interdependent to some significant degree

Groups vary in the degree of cohesion and interdependence

Social Facilitation

The effect of the presence of others on performance

1. Does the presence of others increase or decrease performance?

2. Resolving the Contradiction: Zajonc’s theory

Social Facilitation

Facilitation: dominant response

1. Task is easy

2. Person is expert

Inhibition: non-dominant response

1. Task is hard/complex

2. Person is novice

Social Loafing

Social loafing: decreased effort put forth by individuals when working in a group

Finding: burglars working in groups more likely to get caught!

Ingham (1974): blindfolded ppts pulled 18% harder when they thought were alone

Explanation: diffusion of responsibility

Social Loafing

Less social loafing:Task is challenging and involvingIndividuals are identifiableMembers are friendsGroups are cohesiveIn collectivistic cultures and among women

Group Decision Making

Important decisions are made in groups…GovernmentsJuriesCommitteesCompany executive boards

How do groups affect decision making?

Group Decision Making

Are many heads better than one? Disastrous decisions by groups Ex: Kennedy’s Bay of Pigs invasion Modern example: Iraq invasion Groupthink: social pressures to reach consensus in a

highly cohesive group which leads to disastrous decisions

Group Decision Making

Conditions that foster groupthink:Stressful situationLike minded members of groupIsolation from outside influencesLack of proceduresStrong group leader

Group Decision Making

Symptoms of groupthinkIllusion of invulnerabilityDissent is discouraged, esp. by “mindguards”Self-sensorship, illusion of unanimityOne-sided debate (collective rationalization)Unwillingness to consider alternatives

Group Decision Making

Strategies to reduce groupthink Encourage criticism Input from outside sources Generate different ideas, approaches before decisions

is made Watch out for illusion of invulnerability