1. Group Influence &
Forensic Psychology

2. I. Social Loafing: the tendency for people to
exert less effort when they pool their efforts
toward a common goal than when they are
individually accountable.
A. What is the typical rate of decline in terms of individual effort matched with group size?

3. B. Cultural and Sex Differences
C. Why do we loaf?
1) The Collective Effort Model: people get lazy if they don’t expect their efforts to lead to personally valued outcomes or if they don’t think their efforts will be instrumental in obtaining those outcomes.
D. Social loafing can be reduced.
1) Evaluation and Accountability: when people believe they’ll be individually evaluated on their performance or held accountable, they’ll work harder than they will if they were not being evaluated or not going to be held accountable.

4. II. Group Polarization: group-produced
enhancement of members’ preexisting beliefs
and attitudes (typically via discussion).

5. A. Why does group polarization happen?
1) Persuasive Arguments Theory: the position that has the largest number of arguments supporting it will pull group members further along in the direction of those arguments.
2) Repeated Expressions Theory: having people in a group individually ruminate or state their positions over and over again will also move the group towards greater polarization.

6. III. Personality Factors
A. Authoritarian Personality: a personality that is disposed to favor obedience to authority and intolerant of out-groups and those lower in status.
B. Dogmatic Personality: a personality that is disposed to unfounded certainty in matters of opinion; arrogant assertion of opinions as truths.
C. Out-Group Homogeneity Effect: the perception of out-group members as more similar to one another than are in-group members.
D. Dogmatic and authoritarian people are close-minded and tend to follow authorities blindly.

7. E. Need for Cognition: a personality variable reflecting the extent to which people engage in and enjoy effortful cognitive activities.
F. Need for Closure: a personality variable reflecting an individual’s desire for a definite cognitive closure as opposed to enduring ambiguity.
G. People high in need for cognition & low in need for closure are more motivated to think critically about evidence and entertain various explanations than are people low in need for cognition & high in need for closure.

8. IV. Minority Influence: those who hold an unpopular opinion eventually change the attitudes of those who hold the majority opinion.
A. What facilitates the influence of minorities?
1) Self-Confidence
2) Defections from the Majority: a minority person who defects from the majority is more persuasive than a consistent minority voice.
B. Psychological Reactance: whenever free choice is limited or threatened, the need to retain our freedoms makes us want free choice significantly more than before. Therefore, we will react against the interference.

9. V. Eyewitness Testimony
A. The mere presence of an eyewitness, regardless of credibility, can increase conviction rates.
B. Flashbulb Memories: these occur when you experience something so emotionally shocking that you remember the event, but as time goes by, you forget the details.
C. Memory Reconstruction: during an event, we construct a memory. When we try to retrieve the memory, we reconstruct an account based partly on surviving memories and partly on expectations of what must have happened.
D. The Misinformation Effect: incorporating “misinformation” into one’s memory of the event after witnessing an event and receiving misleading information about it.