Lecture 11: Group Decision Making

Question 1

What are the downsides of group decision making?

Answer 1

• conformity
• authority
• polarisation
• groupthink

Question 2

why is conformity a downside of group decision making?

Answer 2

• can be interpreted as evidence of people’s independence
• in Asch line experiment, the most common number of errors of judgement was 0
• however, social pressure to conform can have negative impacts on group decisions

Question 3

why is authority a downside of group decision making?

Answer 3

• an investigation into a plane crash found that the engineer did not challenge the captain’s decision to proceed with take-off, despite doubting the runway was clear
• when officers of different rank occupied cockpits together, accidents increased
• 40% of junior co-pilots reported not relaying concerns about safety to senior pilots
• unwilingness to challenge authority

Question 4

what is the risky shift?

Answer 4

• stoner asked ppts to state the minimum probability of success they would when considering a risky move in chess
• participants first made this judgement individually, then again as a group
• found that groups consistently endorsed a riskier (i.e., lower probability of success) judgement than the average of the individuals –> term ‘risky shift’ being used to describe the phenomenon of groups endorsing a riskier view than individual members of that group would endorse (on average) by themselves

Question 5

can risky shift happen in both directions?

Answer 5

yes –> term turned to polarisation

Question 6

why is polarisation a downside of group decision making?

Answer 6

• real life implications e.g., jury decisions
• experiment asking ppts to rate how guilty they thought each of 8 cases were and the severity of punishment –> rate individually, discuss half as a group, rate cases again
• ppts showed evidence of polarisation for both guilt and severity of punishment (more harsh if discussed, less harsh if not discussed)

Question 7

what is groupthink?

Answer 7

members of the group become reluctant to criticise and even actively defend the consensus view from outside critique

Question 8

why is groupthink a downside of group decision making?

Answer 8

can lead to poor policy decisions with disastrous consequences, e.g., bay of pigs

Question 9

what are the characteristics of groupthink?

Answer 9

• cohesive groups striking for unanimity and avoiding conflict or criticism
• exacerbated in homogenous teams, where members are, or become, too similar

Question 10

what are the benefits of group decision making?

Answer 10

• wisdom of the crowd
• improved reasoning

Question 11

why is wisdom of the crowd a benefit of group decision making?

Answer 11

• group of doctors with similar levels of diagnostic accuracy will outperform the best doctor in the group
• have to have similar levels of ability

Question 12

when does wisdom of the crowd fail?

Answer 12

• when highly specialised or novel knowledge is required

Question 13

what are suprisingly popular questions (algorithim)?

Answer 13

• ppts answer a question, then ask how other people would answer the question in the same way
• it is possible to determine how popular each answer is expected to be
• the answer that exceeds its expected popularity will very often be the correct answer

Question 14

what is wisdom of the crowd (within)?

Answer 14

an individual make many estimates and average them to improve their individual performance

Question 15

how is wisdom of the crowd (within) achieved by dialectical bootstrapping?

Answer 15

• first, assume that your first estimate is off the mark
• second, think about a few reasons why that could be. which assumptions and considerations could have been wrong?
• third, what do these new considerations imply? was the first estimate too high or too low?
• fourth, based on this new perspective, make a second, alternative estimate

Question 16

what is wisdom of the crowd good at cancelling out?

Answer 16

• effective at cancelling out random error
• not so effective at cancelling out systematic error, e.g., anchoring

Question 17

what study found irrational individuals with collective rationality?

Answer 17

• experimenters gave ants 2 choices of nest, individuals torn 50-50
• when a decoy nest (similar but worse) was introduced, the ants reliably chose the nest that dominated the decoy
• when colonies made the decision, there was no sign of the decoy effect –> collective rationality

Question 18

how is improved reasoning a benefit of group decision making?

Answer 18

• groups often do better than individuals, and often even better than the best individual in the group (except for groups of 2)

Question 19

what study was conducted which demonstrated improved group reasoning?

Answer 19

• Moshman & Geil observed groups settle on the correct answer, none of the members initially selected the P and notQ cards.
• Implies that collective reasoning improves people’s performance relative to what they could achieve individually
• P Q card reasoning task