The Importance of Diversity

From "The Trouble With Elections: Everything We Thought We Knew About Democracy is Wrong," Chapter 11.4

A key for bringing forth information and insights that might be ignored by confirmation-biased, motivated reasoners, and experts, is to have broad diversity within the body that is crafting a proposal. I wrote a bit about diversity in chapter 7 when discussing descriptive representation. Even if one were skeptical about the importance of having descriptively representative decision-making bodies, (instead favoring a more skilled, or expert group, — “wise and virtuous” as the Founders would say), diversity is still crucial. A group’s competence hinges on diversity, rather than a mere summing of individual participant competence. 

Elections are often regarded as a way to get the best among us together to solve the problems of society. But this conception is, to say the least, problematic. Margaret Heffernan, a professor of management at the University of Bath, whose interest in productivity drew her to the work of the evolutionary biologist William Muir, gave a TED talk discussing his research. Heffernan described how Muir studied hens, because it is so easy to measure their productivity (you simply count the eggs). To determine what might make hens more productive, Muir devised an experiment: he selected an average flock and let it alone for six generations but also separated out the individually most productive chickens and put them together in a superflock. In each successive generation, he selected only the most productive for breeding. After six more generations had passed, he found that the first group, the average group, was doing well. The hens were all plump and fully feathered, and their egg production had increased dramatically. In the superflock, however, all but three hens were dead. The three had pecked the rest to death. The individually productive chickens had achieved their success by suppressing the productivity of the others. While not directly applicable to human societies, it serves as a metaphor about the danger and unintended consequences of seeking out the best. As Heffernan observes, most organizations and some societies are run in accordance with this superflock model, on the assumption that success is achieved by picking superstars and giving them all the resources and power. The result has been the same as in Muir's experiment: aggression, dysfunction, and waste. 

Even if we naively believed that the U. S. Congress was made up of the best and brightest, the homogeneity of the members is not only unrepresentative but also a liability in terms of group competence when making decisions. Legal scholar, Cass Sunstein, in his book Why Societies Need Dissent, explains how research consistently shows the importance of diversity to optimal decision-making. The observation that diversity trumps homogeneity in groups of problem-solvers is hardly startling: two heads are better than one only if the two are thinking somewhat differently from one another. But the importance of diversity goes far deeper. As James Surowiecki notes, in his best-selling book The Wisdom of Crowds, diverse groups outperform homogeneous ones in many situations, even when the homogeneous group is made up of experts. By definition, experts are those who have experience solving certain kinds of problems, but while that experience may be helpful, it may also act like blinders (hence the adage that generals are always fighting a previous war of their experience). One is better off relying on a diversity, rather than a specialization, of experience and expertise; as Surowiecki observes,

“if you put together a big enough and diverse enough group of people and ask them to ‘make decisions affecting the general interest,’ that group’s decisions will, over time, be intellectually superior to the isolated individual, no matter how smart or well informed he is.”

Exactly what kind of diversity (e.g. cultural, age, cognitive style) is desirable depends on the task at hand. For certain tasks, both diversity and expertise may be irrelevant. For other tasks a diverse set of life experiences are highly relevant. Within the realm of public policy making, seeking out any particular sort of diversity (or expertise) is futile, since it often cannot be known in advance what sort of diversity is important for a particular decision — leaving random selection as the optimal strategy.

Even a conservative such as Edmund Burke saw value in diversity within a legislature, with deliberators representing every relevant point of view. Awareness of the value of diversity dates back at least to Aristotle, who wrote that,

“for the many, of whom each individual is but an ordinary person, when they meet together may very likely be better than the few good, if regarded not individually but collectively, just as a feast to which many contribute is better than a dinner provided out of a single purse.”

Aristotle seems to foreshadow Wikipedia and “crowdsourcing.”

At the time of the debates over the ratification of the United States Constitution, the issue of diversity was raised implicitly in many arguments of Anti-Federalists. Melancton Smith, a prominent merchant and major landowner in New York, argued in 1788 that good governance required that legislators not be restricted to members of the “natural aristocracy” or “first class.” To have the necessary knowledge to adopt wise public policies, the representative body must include the middle classes. In addition to the knowledge held by the wealthy and well educated, the legislature

“should also comprehend that kind of acquaintance with the common concerns and occupations of the people, which men of the middling class of life are in general much better competent to than those of the superior class.”

Including members of racial, religious, and cultural minority groups in deliberation as well has the potential to increase understanding and sympathy for other perspectives and policy preferences among majority participants. (This result is not automatic, however, and some research suggests there is also a potential for increased polarization.) The details of how the deliberation is structured and conducted is crucial.

Diversity does not merely refer to familiar demographic parameters such as race, class, and sex that exactly mirror the community.  Political scientist Joel Parker put it this way:

“We don’t need representatives to ‘represent’ directly any particular set of static interests.  That interests may in fact be shaped by the representative process, and not simply reflected, is ultimately an argument for the importance of resemblance to representation. We need representatives to practice good judgment, perhaps more than we need them to hold precisely the same preferences, in the same combinations, as the rest of us. Interests should arise from, rather than drive, this collective good judgment.”

Political theorists such as Hélène Landemore have stressed “cognitive diversity” or problem-solving styles as well. Cognitive diversity is not just a matter of different perspectives arising from different upbringings and life experiences, which may be associated with categories such as race, sex, or class, but differences in personality and even brain function—different ways of seeing, interpreting, and making predictions about the world. Landemore has written extensively about the epistemic benefits of maximizing cognitive diversity in political decision-making bodies. She contends that this can optimally be achieved through random selection of group members. The ability of random selection to generate a far more representative body than elections is, she argues, self-evident, and also confirmed by all sorts of pilot sortition implementations in the form of citizens’ assemblies. This representativeness is not symbolic or token, but deep. It reflects not only the sex, race, class, age, ethnic makeup, values, life experiences, religious beliefs (or lack thereof), occupations, interests, and political philosophies present in the community, but also its range of cognitive styles, in a way that no elected chamber could ever match.