Diversity isn’t just about justice. It’s about helping us make better collective decisions.

Publication Type: 
Other Writing
Publication Date: 
September 28, 2017

Scott Page is a professor of political science at the University of Michigan, and the author of The Diversity Bonus, a new book based on his research on diversity and collective decision-making (some of which has been developed and presented at workshops organized by the MacArthur Network on Opening Governance). I asked him questions about the implications of his work.

HF: Former Supreme Court justice Antonin Scalia suggested that there was a trade-off between allowing more diversity (e.g. admitting more diverse students to a university) and higher quality. Your book argues that Scalia is dead wrong about many situations. Why?

SP: I argue that Scalia is right in some cases but wrong in the cases that were before the court. Scalia assumes that we have some straightforward method for evaluating people’s ability and it’s one dimensional. He then assumes that the overall ability of a group is no more than and no less than the sum of the abilities of its members.

That calculation may be right for simple routine tasks like chopping wood. If I am able to chop down 10 trees an hour, and you can chop eight, together we can chop 18. But colleges, universities and big firms carry out more complicated tasks — designing aircraft, conducting neuroscience research and analyzing health-care policies. Here, unlike woodchopping, we cannot reduce ability to a single dimension (the number of ideas that an engineer has per hour about how to design aircraft wings is a silly measure of intelligence). And, even if you could measure ability, the team or group’s ability would not be the sum of its members abilities (by working together on designing an aircraft, we may have better ideas than either of us could ever arrive at on our own).

Instead, the ability of the team depends on the knowledge, skills and ways of thinking that its members possess. As I lay out in my book, the best team of people to carry out a complex task will not necessarily be the people who score best at any particular test. It should instead be a team of people with different cognitive toolboxes and bases of knowledge to draw upon.

The cases before the court were not about hiring woodchoppers.  Scalia’s arguments are demonstrably a bad fit for research universities — where his logic was being applied — which confront complex problems where neither assumption holds. You can only make a university work properly if you draw on diverse people, with diverse points of view and understandings. His logic also fails in the tech industry, pharma, consulting, finance and just about anywhere in the knowledge economy.

HF: What is the “bonus” that diversity of viewpoints can produce in situations where people have to figure out the answers to complex problems?

SP: I’m a mathematician by training, so when I say that diversity of viewpoints can produce bonuses, what I mean is that we can measure team performance and demonstrate that the diversity of the team adds a measurable bonus.

Imagine that you ask five people to make predictions about the unemployment rate or the vote share of a presidential candidate in an election. Then take the average of their individual predictions, and call this the group’s prediction. The group’s prediction will have less error than the average error of its individual members. The amount by which the group is better than its average member — the “bonus” — corresponds to the diversity of their predictions. Similar arguments explain why problem solving, innovating and verifying all produce quantifiable diversity bonuses. The math’s all in the book.

The diversity bonus logic differs from a portfolio logic in which people buy a portfolio of stocks to insulate themselves from risk. The return from a portfolio of stocks equals the average of the individual stocks’ returns. It does not produce any bonuses. When we look at how diversity works in cognitive tasks, it does more than spread risk. It produces bonuses. Thus, the math suggests your teams should be more diverse than your stock portfolio.

Read the full piece at The Washington Post