12.1 Wisdom of Crowds and Herd Thinking

Learning Goals

[Link to PlayPosit]

More details

After this lesson, students should

1. Not take for granted that consensus offers the best conclusions.
2. Take seriously (but not as absolute!) the consensus of a group which has reasoned about a question in a careful, appropriate way.
3. Take seriously (but not as absolute!) the average of a large group's independent estimates of a number, under appropriate conditions.

Definitions

• Wisdom of Crowds: Sometimes groups make better judgments than individuals. This happens when
  • Judgments are genuinely independent, preventing herd thinking.
  • Members of the group do not share the same biases.
  • There are enough people in the group to balance out random biases or fluctuations (analogous to the need for an adequate sample size).
  • Works especially well when estimating a quantity, where errors may be large but are not systematic.
• Herd Thinking: Sometimes groups make worse judgments than individuals. This happens when
  • Judgments of individuals are influenced by the judgments of others, leading to groupthink and sometimes polarization.
  • Members of the group share biases, which can be exaggerated by discussion and cannot be decreased by averaging judgments.

Examples

• [item 1]

Common Misconceptions

• Mistaken quote

  Explanation.

Context

This lesson discusses when groups of people make better or worse judgments than individuals. It leads into the last part of the course, which revolves around group decision making, e.g. as a society.

Before

3.1 Systematic and Statistical Uncertainty

Individual judgments can deviate from the truth due to systematic bias and random fluctuation. Reducing shared bias and increasing sample size are ways to improve the effects of Wisdom of Crowds.

8.2 Heuristics and Biases II

Conformity to the group consensus, illustrated by the Asch experiment, and obedience to a perceived authority in a group, illustrated by the Milgram experiment, are psychological tendencies that affect group decision making.

10.1 Confirmation Bias

Confirmation bias can exacerbate other biases in group decision making, such as the motivation to make judgments that conform to the group consensus or agree with the opinion of the authority figure.

After

12.2 Denver Bullet Study

When making group decisions using the Denver Bullet Study method, it is important to survey each expert (on matters of fact) and each stakeholder (on matters of value) individually and independently so as to reduce "herd thinking" effects.

13.2 Deliberative Polling

In a somewhat opposite approach, deliberative polling encourages moderated discussion between all participants punctuated by dialogue with the relevant experts, before participants answer a poll to make informed decisions in society. Conformity with other participants as well as "obedience" to (in the sense of taking advice from) the expert panelists are essential features. The result tends to be a convergence of opinions towards moderation on divisive issues.

Recommended Outline

Before Class

• [Any essential logistical things that need to be done for this class]
• Prepare a seating chart.
• Review PlayPosit and discussion questions and ask faculty, Gabriel, or Emlen any questions you have.
• (Optional) Prepare a presentation.

During Class

• (5 min) Come up with some fun way to assign the roles of spokesperson and notetaker (e.g. earliest birthday in the year, lives furthest from campus). Remind them of the responsibilities of these roles.
• ([#] min) [Description of some module from #Lesson Content]
• (5 min) Collect questions for plenary.

After Class

• [Any essential logistical things that need to be done as followup for this class]
• Collect answers from notetakers for the forum / plenary.

Lesson Content

Clicker Question

1. Question
   1. First option
   2. Second option
   3. Third option
   4. Fourth option

Activity 1: Name

[Brief description of and motivation for the activity]

Discussion Questions

1. Question 1
   1. Subquestion a

   2. Subquestion b
2. Consider the following passage from the Scientific American article "How Diversity Makes Us Smarter",[1]

"Members of a homogeneous group rest somewhat assured that they will agree with one another; that they will understand one another’s perspectives and beliefs; that they will be able to easily come to a consensus. But when members of a group notice that they are socially different from one another, they change their expectations. They anticipate differences of opinion and perspective. They assume they will need to work harder to come to a consensus. This logic helps to explain both the upside and the downside of social diversity: people work harder in diverse environments both cognitively and socially. They might not like it, but the hard work can lead to better outcomes."

How does homogeneity in groups contribute to herd thinking? What benefit does diversity therefore provide?

Collect Questions for Plenary

(5 min) Collect remaining questions from the students for faculty in plenary (can be questions for clarification, extension, discussion, etc.), and add [ here].