What is tolerance and how much of it do democracies require?

When tensions based on differences arise, some leaders often call for “greater tolerance” of groups or ideas and promote the notion of “a more tolerant society.” For example, speaking out against racism, then Secretary-General of the United Nations Kofi Annan said, “Tolerance, inter-cultural dialogue and respect for diversity are more essential than ever in a world where peoples are becoming more and more closely interconnected.” Indeed, tolerance is often invoked as something to which individuals and societies should aspire. According to former Director-General of UNESCO Audrey Azoulay, “Tolerance is an act of humanity, which we must nurture and enact each in our own lives every day, to rejoice in the diversity that makes us strong and the values that bring us together.”

Yet what does this mean in practice? Even if we all agree that some degree of tolerance is necessary for democracy, it is not clear whether societies should always strive for more. Deeply troubled by the Nazi and Fascist movements of World War II, philosopher of science Karl Popper cautioned against unlimited tolerance, because, paradoxically, it may lead to the disappearance of tolerance itself: “If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them…We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant.”

For decades, the idea that protecting liberal democracy and its citizens meant we should not tolerate speech, ideas, or groups that infringe on others’ freedoms and civil liberties was most prevalent among those fighting for the inclusion of minority groups. Yet, in recent years, this same “paradox of tolerance” argument has also been used to advocate for the exclusion of minority groups. For instance, Geert Wilders, the leader of the Dutch Party for Freedom (PVV), uses this same language to justify his view that Muslims should not be allowed to immigrate to the Netherlands: “Multiculturalism made us tolerate the intolerant, and now intolerance is annihilating tolerance. We should, in the name of tolerance, claim the right not to tolerate the intolerant.”

Wilders’ sentiments about the limits of tolerance ostensibly echo Popper’s; however, their ideas about where to draw the line differ. Popper maintained that most forms of diversity should be tolerated. He did not draw the line at the existence of ideas or ideologies that are intolerant of diversity, but instead at incitement to persecute individuals and groups based on some expression of diversity. Wilders advocates for the exclusion of an entire population (based on religious background), something Popper opposed.

Questions of tolerance are central to many of the existential debates that characterize modern politics, like whether hate speech is free speech or whether bans on religious clothing violate freedom of religion and expression. And, the strikingly similar statements above highlight the most challenging aspect of studying tolerance: analytically distinguishing between the limits of tolerance and prejudice. What does it actually mean to be tolerant? Is it putting up with something disliked, like the presence of an out-group? Is it the absence of prejudice towards members of minority group? Or, is it acceptance of or even enthusiasm for diversity? What levels of tolerance do democracies require to function well? How much tolerance of diversity is required of us? Unfortunately, science has not provided many answers.

Historically, political scientists have been most concerned with the empirical study of tolerance. Published between the 1950s and 1990s, seminal studies operationalized tolerance as the willingness to extend civil rights to disliked or unpopular groups in society. While certainly a topic worthy of investigation, by incorporating prejudice into the definition and measurement of tolerance, it is difficult to separate (analytically or empirically) dislike of an out-group from reactions to diversity itself. Indeed, whether or not one supports civil rights for neo-Nazis probably also reflects one’s attitudes towards neo-Nazis.

Meanwhile, sociologists and social psychologists have tended to define tolerance more broadly, focusing instead on positive or negative reactions to the existence of different values, behaviors, and lifestyles. In this conceptualization, dislike of an out-group is not a prerequisite for the possibility of tolerance. Instead, tolerance may be putting up with something disliked or it may be to show genuine esteem for something different. Seeing tolerance as something multidimensional is closer to how political philosophers have understood the concept, with its most diversity-embracing form echoing the prescription contained in the Preamble of the United Nations Charter. However, due to data limitations, empirical studies that define tolerance this way nevertheless use attitudes towards minority groups to measure intolerance. For example, studies have relied on survey items that gauge respondents’ willingness to have members of certain groups as neighbors.

Answering some of the pressing, if not existential questions facing diverse, democratic societies require a clearer understanding of tolerance. Yet before we can begin to assess its impact on various aspects of social, political, and economic life, we need better tools to measure it.

In our recently published research, co-authored with Andrea Bohman and Filip Fors Connolly, we define tolerance as a value orientation towards difference. Synthesizing earlier theoretical work, we identify three expressions of tolerance: acceptance of, respect for, and appreciation of diversity.

The first, acceptance of diversity, is the most basic form of tolerance and constitutes a permissive relationship between members of different groups. In this form, members of different groups do not interfere with each other or their practices but instead accept their presence in society.

The second and third expressions of tolerance are more demanding. Respect for diversity means seeing different groups as morally and politically equal even though they may differ fundamentally in beliefs, practices, and lifestyles. Appreciation of diversity means viewing different beliefs, practices, or lifestyles as something intrinsically valuable and worthy of esteem.

To aid in the development of survey items that capture these three expressions of tolerance, we ran two pilot studies in 2014 and 2015. Then, in 2016, we administered a nationally representative paper survey in Sweden and an online survey in Australia, Denmark, Sweden, the United Kingdom, and the United States. The open access article describes in detail this process, the survey items, our samples, as well as all analyses conducted. Statistical analyses provide support for our proposed model of tolerance in that we find empirical evidence for the existence of these three expressions of tolerance. Results also show that respondents across countries have a similar understanding of these three expressions.

Importantly, we designed survey questions to capture reactions to diversity itself instead of attitudes towards particular out-groups. Further, our measures are temporally and politically neutral, which improves upon earlier research that primarily focused on the extension of civil liberties to groups associated with the political left but not political right. With an abstract approach to the study of tolerance, we avoid conflating intolerance with conservatism and tolerance with progressivism, which is critical given the meanings of conservative and progressive change over time. Only politically and temporally neutral items make it possible to study the causes and consequences of tolerance over time and cross-nationally.

How much tolerance is necessary to reduce discrimination, violence, and other social problems that undermine democratic societies? What expressions of tolerance—acceptance of, respect for, or appreciation of diversity—ensure individual rights while promoting democratic values? We do not have these answers, but by developing tools to study tolerance, we are one step closer to addressing these types of questions.