(Editor’s note (1/30/16): In response to President Donald Trump’s immigration order to close U.S. borders to refugees and visitors from seven predominantly Muslim countries, which has impacted scientists and students, we are republishing the following article from or 2014 special report on how diversity powers science and innovation.)

Collaboration has been a recurring theme in science and technology in recent years. The life of the mind is increasingly transnational in nature. It roams centers of excellence from every continent, linked by communications of great speed and breadth.Twice we have looked at collaboration in our State of the World's Science reports, last year with a focus on innovation, the year before on basic research. Here we address it again, from the standpoint of the individual.

The word “diversity” is shorthand for a vast effort to remake society to include everyone—not just those in privileged positions—in politics, culture and the pursuit of happiness. This ambition goes well beyond the scope of this report; we have stayed within the realm of science and its activities. Because we prefer to look at evidence, we take the opportunity to focus on the empirical grounding of diversity, which often gets lost in the larger conversation.

Diversity, it turns out, goes to the heart of how to do research and innovation effectively. In the scientific literature, it is clear that diversity speaks directly to the quality and effectiveness of teams. As Katherine W. Phillips tells us, starting on page 42, when we have to work with people who are not like ourselves, we tend to prepare more thoroughly and work harder to marshal our arguments, and we do better work as a result. Diversity is beneficial for teams precisely because we react differently to people who are different from us. If the end goal is excellence, diversity is an essential ingredient.

For diversity to be effective, the working environment must be right. For an individual, it takes conscious effort to be on the watch for unconscious biases and to overcome them. For an organization, it takes processes, procedures and an ethos of acceptance. Victoria Plaut points out, beginning on page 52, that groups who abandon color-blind policies and embrace the differences among their members in ways that do not stereotype or pigeonhole tend to be successful in taking advantage of what diversity has to offer.

We do not treat diversity exclusively as a utilitarian matter in this special section, of course. Science imposes the discipline of having to find the best ideas among varied teams of people, which gives scientists and engineers the opportunity to be pioneers in cultural change. So we have sprinkled this package with essays from some extraordinary people who are embracing that challenge.

We would like to have included a Diversity Index—a measure of how nations fare when it comes to inclusiveness in the science and technology workforce. At the moment that is too tall an order, however. In a welcome development from two of the world's most visible technology companies, Google and Apple recently released data on the diversity, or lack of it, of their respective workforces. It is a drop in the information bucket, however. Data overall are scarce, for several reasons.

Racial and ethnic identity, for one, are hard to define consistently. A United Nations census found that two thirds of nations categorized their populations along these lines but used a kaleidoscope of terms— race, ethnic origin, nationality, ancestry, tribal, Aboriginal, and so on. Many countries track the poor and underprivileged, but these categories mean different things in different places. Disability is even more difficult to pin down. Gender is easier to define (although ambiguities exist there as well), but little information is gathered that is specific to the science-related workforce. “Comprehensive, internationally comparable data on the worldwide science and engineering workforce do not exist,” says the National Science Foundation in its Science and Engineering Indicators 2014 report. From what we do know, however, it's clear that we can do better.

To that end, we believe that data should be a high priority. Scientists pride themselves on their objectivity, but personal experience and point of view have a lot to do with what questions get asked in the first place and how researchers go about answering them. The people in science and engineering are driving the world's most vital engine of prosperity and new ideas. Who are they?