National Academies Press: OpenBook
« Previous: 5 Innovation in Food Production and Distribution to Reduce Environmental Footprint
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

6

Concluding Discussion

In the concluding session of the workshop, moderated by Erik Olson, Natural Resources Defense Council, Washington, DC, five previous speakers or moderators participated in a panel discussion: Adam Drewnowski, Jessica Fanzo, Diego Rose, Marco Springmann, and David Tilman. The session opened with Olson asking the panelists to reflect on the workshop and share their takeaways. He then described a hypothetical future scenario involving a meeting in the White House and asked each panelist to imagine him- or herself as the Czar of Sustainable Foods. He asked the panelists what they would say to each of the other people present at the meeting (the President, Bill Gates, and the chief executive officer [CEO] of Walmart). The session ended with an open discussion with the audience. This chapter summarizes the information and opinions that emerged during this session.

OVERALL IMPRESSIONS AND TAKEAWAYS

The Overwhelming Nature of the Data, the Complexity of the Science, But Promising Steps Forward

Fanzo commented on the rich conversations that had taken place over the course of the workshop and the many different perspectives from science and the private sector they reflected. She noted, however, a gap in representation from government and policy makers and the need for more voices from the social sciences. She also found the data to be a bit overwhelming, while acknowledging that this is an inevitable result of the

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

complexity of working in such a multidisciplinary space. Reflecting on the controversy surrounding the Food and Agriculture Organization (FAO) report Livestock’s Long Shadow: Environmental Issues and Options (FAO, 2006), she described how someone without expertise in a particular area can “go down a rabbit hole” and believe that the content of whatever he or she is reading is robust, whether it is or not. Given the difficulty that even she has in interpreting climate data, she imagined that it must be extremely difficult for consumers, producers, and policy makers to “weed through” and make sense of the science. She observed further that some people believe what is in the FAO (2006) report, while others are very critical, depending on their perspectives, incentives, and funding. Context always matters, she stressed.

At the same time, given the many minds being brought together to address sustainability, Fanzo expressed hope. Using the United Nations (UN) Sustainable Development Goals (SDGs) as a framework and having conversations such as those at this workshop is, she argued, “a promising step compared to where we were 5, 10 years ago.”

Equity, Trade-Offs, and Unanswered Questions

Tilman identified the issue of equity as a recurring theme over the course of the workshop. In his opinion, the world will be stable in the long term only if greater equity exists among individuals both within and across societies. He observed that the poorest countries are now among those with the highest economic growth rates; thus, 50 to 100 years from now, there will be much greater economic equity among countries. But there will be a cost to that equity, he asserted, because of the greater per capita environmental impacts that richer individuals tend to create. Diet has major implications for human health, he added, but asked what the environmental impacts will be of people worldwide living longer, healthier lives, with lower morbidity and mortality rates.

Tilman also was bothered by some of the comments about relative greenhouse gas (GHG) emissions among nations. For him, the question is, “What do we on average, as a citizen of Earth, have the right to do if we are going to have a world that is really equitable and sustainable in the long term?”

While Tilman acknowledged not having answers to these questions, he believes much of the change needed is behavioral. For him, the most difficult question is how to come to grips with the various costs and benefits of how people live and how they agree as individuals, as nations, and globally about choices around foods, energy, land, water quality, and other

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

issues related to sustainable diets. He expressed his hope that there is still time for rational thought and change. “It’s not a freight train about to hit a wall,” he acknowledged. Nonetheless, he argued, sustainable life on Earth not just 10 years from now, but 1,000 and 10,000 years from now, will require a multidisciplinary, multicultural approach that recognizes global interdependence.

Shifting Toward More Plant-Based Eating

Springmann agreed with Fanzo’s and Tilman’s remarks about the need for multiple perspectives. However, he did not find the data overwhelming or the questions unanswerable. For him, looking at different perspectives actually helps reduce confusion and clarify direction. He explained that the basic factor underlying the differential environmental footprints of animal- and plant-based foods is the feed conversion ratio; that is, it always takes more feed to feed animals than if humans were to eat the feed themselves. He remarked on the extensive discussion during the workshop, particularly in the last session (summarized in Chapter 5), on GHG emissions associated with different diets. But he stressed that it is also clear that if people in high meat-consuming countries were to eat less meat, especially less red and processed meat, large health benefits would result, citing as an example that there is a possible mechanistic explanation for an association between red meat, for example, and colorectal cancer. Thus, he summarized, there are benefits in both dimensions—environmental and human health. He added that plant-based foods in general are known to be cheaper—perhaps not in supermarkets such as Whole Foods where plant-based foods are marketed to a specific demographic, but generally from a production perspective. The challenge, he asserted, is how to structure the food system to make those foods available. Overall, he argued, a dietary change toward a more sustainable diet probably means a shift toward a more plant-based diet.

Springmann clarified that this observation does not necessarily mean that everyone needs to become vegan; rather, it means a shift toward plant-based eating. The challenge, he suggested, is how. He referred to Ranganathan’s presentation (summarized in Chapter 4) on lessons learned from private-sector marketing on how to shift behavior. He speculated that it is probably unrealistic to expect people to eliminate meat from their diets entirely, but it is more likely that some people would eat vegan for a certain amount of time each week. He encouraged the retail sector to provide plant-based products so that people would have that choice, stating that if people ate red or processed meat only once per week, for example, the world would probably be much more sustainable.

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

The Complexity of Sustainable Food Systems, the Challenge of Obtaining Good-Quality Data, and the Issue of Health Equity

The first takeaway for Drewnowksi was that sustainable food systems are complicated, multisectoral, and transdisciplinary and that achieving sustainability will require the involvement of a range of expertise, from social science to epidemiology to the food industry. For him, it is helpful to revisit the FAO definition of a sustainable diet and its four domains: (1) health and nutrition, (2) economics, (3) society, and (4) the environment. Thus, he stressed, the environment is only one of several domains of a sustainable diet, and he urged greater consideration of the broader picture and other parts of that picture, from affordability to labor issues to health equity. In his opinion, focusing only on the environment can be misleading, especially since the environmental context is so different from one country or geography to another—even within the United States. Globally, he pointed out, there are differences not only in context, but also in the quality of environmental data.

Indeed, the need for good-quality data was a second take-home message for Drewnowski. Referring to Afshin’s presentation on the health metric, consumption, and other data that the Global Burden of Disease (GBD) project is combining, coding, and converting into models (see Chapter 3), he commented on the complexity of understanding even where dietary data are and sustainable diets based on those data can be modeled. In Drewnowski’s opinion, while GBD has been extremely expensive, it is “money well spent,” given that it has created the best picture available of the global burden of disease.

A third takeaway for Drewnowski was the issue of health equity. There is no standard diet, he asserted; rather, different people consume different diets with different costs. He mentioned again that in Seattle, he has observed differences in obesity rates on the order of 600 percent based simply on where people live—a socioeconomic difference that dwarfs any kind of difference by race, ethnicity, age, sex, or any other factor. He encouraged workshop participants to keep in mind the issue of diet disparity and health equity.

Providing Sustainable Diet Guidance, Understanding What Drives Individual Behavior, and Communicating Among Disciplines

Rose drew a parallel between the workshop discussion on sustainable diets and the dietary guidance process in the United States. He explained that in the late 1970s, before the first Dietary Guidelines for Americans (DGA) was issued in 1980, the U.S. Senate issued a set of dietary guidelines

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

called The Dietary Goals for the United States. That senators were promulgating guidelines prompted the nutrition community, as well as the legislative community, to call for the involvement of professionals. In Rose’s opinion, one of the wise decisions made when the first DGA was issued was to revisit the guidelines every 5 years. Thus, he observed, experts can communicate to the public what is understood based on the best available science, knowing there will be an opportunity in another 5 years to revise their recommendations. “I think we are sort of at that point here with sustainable diets,” he suggested. Much is known and can be communicated to the public and policy makers now, and this information can be revisited in 4 to 5 years to see whether any changes should be made to the advice offered.

Another takeaway for Rose was the importance of modeling at the individual level, given that it is individuals who make decisions about what to eat (as described in Heller’s presentation, summarized in Chapter 5, on their joint work in linking environmental impacts to National Health and Nutrition Examination Survey [NHANES] dietary data). “That is where the change happens,” Rose asserted. If the goal is to move people toward less waste and a more plant-based diet, he elaborated, it is important to know what motivates individuals. Thus, he called for a greater focus on drivers of individual-level change, noting that Ranganathan had described some of these drivers in her presentation (summarized in Chapter 4). He added that, although there had been little discussion about social media at the workshop, they are known to be a powerful driver of behavioral change and are used a great deal in marketing. “I think we need to tap more into that,” he said. Thus, he echoed calls to expand expertise at the next workshop on sustainable diets to include more social scientists, including sociologists, anthropologists, and economists, as well as marketing experts. Because policies and the food environment are also important drivers of change, he argued further for political scientists and politicians to be present in future discussions to enable a better understanding of how politicians perceive the world and what political drivers can create the will to make the necessary changes.

Finally, Rose stressed that having all of these different people in the room will require getting better at interdisciplinary communication. He mentioned that in his own work, Heller is an example of someone from another discipline with whom he has resolved language issues, differences in publication style, differences in how data are handled, and other challenges, and he suspects that anyone working as part of an interdisciplinary team has had a similar experience. “I think it is a challenge that we need to keep pursuing,” he said, “because that is how we are really going to get to a better conclusion.”

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

A HYPOTHETICAL SCENARIO: WHAT WOULD YOU SAY?

Olson asked the panelists to imagine a hypothetical future scenario in which a new President has just been inaugurated, and “you,” the panelist, have been invited to the White House as the Czar of Sustainable Foods to meet with three people: (1) the President, who wants to hear what you, the new Czar of Sustainable Foods, have to say; (2) Bill Gates, who is going to give money to nongovernmental organizations (NGOs) to do whatever he wants them to do; and (3) the CEO of Walmart. You are each allowed two sentences, he instructed the panelists, to tell each of these three people the number one thing they should do.

Drewnowski began. He offered that he would say to the President that the major problems with diet quality are related to income and socioeconomic status and that the “first order of the day” is redistribution of income. To Bill Gates, he would call for accountability. He would tell Gates that it is time to step away from foundations that are not accountable to anyone and to restore functions formerly served by FAO, the World Health Organization (WHO), and government institutions. To the CEO of Walmart, he quipped, “I would say, ‘What are you doing about Amazon?’”

For Springmann, the number one thing he would ask of the President would be to eliminate what he characterized as the “crazy” dairy recommendations in the DGA. He referred to results from Heller’s research showing the role of dairy in nonsustainable diets (see Figure 5-4 in Chapter 5). He would also ask the President to revise the U.S. calcium recommendations, as they underpin the dairy recommendations. As for Gates, Springmann agreed with Drewnowski’s response. In addition, he would ask Gates to rethink official development aid, for example, and instead of investing in specific food groups, think about how to develop sustainable food systems holistically in developing countries. He would suggest that Gates perhaps engage Walmart’s help in cold chain logistics. And he would suggest to the Walmart CEO that the company think more about food groups and their role in sustainable diets.

Tilman would encourage the President to choose a cabinet and cabinet secretaries based on their ability and desire to advance a science-based agenda throughout government. He expressed his view that “with a science-based agenda, we can address many of the problems that this group has been discussing.” He would encourage the Walmart CEO to find ways to package and sell foods that reduce waste at the consumer level. In addition, he would request that Walmart use its marketing skills to encourage consumers to purchase more fruits and vegetables. To Gates, he would request money for a Nobel-like prize for developing and popularizing the best tasting, healthiest foods possible. Each year, the winners would be chosen based on an international contest with a highly publicized televised cook-off.

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

Fanzo would ask the President to commit to the SDGs and to hold the United States accountable for attempting to achieve those goals. She would ask Gates to invest more in nutrition. According to Fanzo, Gates has historically not been convinced of the case for nutrition, particularly undernutrition, and the current portfolio for nutrition of the Bill & Melinda Gates Foundation is very small compared with health or even agriculture development. “I would present the case to him that diets are incredibly important,” she said. Acknowledging the impossibility of such a request, she would say to the Walmart CEO, “Stop selling junk food.” She would suggest that Walmart be the first retailer not to have any junk food in its stores. “Wouldn’t that be amazing?” she asked.

To the President, Rose would argue the importance of sustainable diets, particularly with respect to climate change, and he would point out the many tools in the President’s administration available for addressing this issue (e.g., guidelines, food labeling, taxes). Like Fanzo, he would encourage Gates to increase the foundation’s nutrition portfolio. Also like Fanzo, he would urge the Walmart CEO to reduce the sale of junk food. In addition, he would urge Walmart to reduce food waste and, more generally, commit to sustainable foods.

QUESTIONS FROM THE AUDIENCE

Different Approaches to Analyzing and Interpreting Data on Sustainable Diets

Tahiri agreed with Fanzo’s remarks about the overwhelming nature of data on sustainable diets. For her, it is as though everyone is climbing the same mountain, but from different angles. She finds this to be especially true with respect to modeling the population effects of changes in meat consumption. She asked whether it is possible to consolidate all the different datasets that had been examined over the course of the workshop.

Springmann countered that the different perspectives and multiple data sources discussed throughout the workshop are not to be discouraged. He described the data as “imperfect descriptions of reality.” So in his opinion, the more sources there are, the better—one can then ask the same question of the different sources to see if they agree.

Rose added that in a way, a convergence has already taken place. He mentioned results from the models Springmann had described (summarized in Chapter 4) converging with results from the individual-level study described by Heller (summarized in Chapter 5). “Basically we are seeing some of the same patterns,” Rose said, including that food waste and beef and dairy are driving many of the environmental impacts of the food system.

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

The Four Dimensions of Sustainable Diets

Tahiri expressed concern that the focus on the environmental dimension of sustainable diets and the failure to consider the other three components (health and nutrition, economics, and society) is worse than misleading, as Drewnowski had observed. In her opinion, if health, affordability, and accessibility are not taken into account, it will be impossible to convince consumers and others who need to be convinced to do what is necessary to advance sustainable diets. She observed that there had been little discussion during the workshop about how to be an ambassador for all four components of sustainability, not just the environmental component.

Drewnowski referred to Tilman’s idea of a “great cook-off” to find a food that is nutrient-rich and also affordable, appealing, and planet-friendly. “What is that food?” he asked. He agreed that affordability in particular is of utmost concern, as it “goes to the heart of health equity.”

Related to these other dimensions of sustainability, an audience member suggested that perhaps another workshop should be planned to focus on the economic impacts of the dietary transitions that had been discussed at this workshop. She expressed particular interest in the impacts on farmers’ incomes in developing countries, but also in developed countries, given that 28 percent of the global workforce is in this sector. If farmers do not earn a decent living, she argued, they will be unable to invest in the productivity increases needed to reduce the environmental impact of agriculture.

Fanzo agreed that this would be a great workshop idea, calling attention to a recent Lancet series on the economics of noncommunicable diseases. “I think we need the same thing,” Fanzo said, but on the economics of nutrition outcomes.

Breaking Down Silos and Thinking More Holistically

Kate Houston of Cargill, Inc., suggested that part of the challenge to addressing all four components of sustainable diets is that everyone acknowledges the components’ equal importance, yet, she said, “we get so siloed in our work.” She added that this is the case even in companies, where experts are working to solve different elements of a broader challenge. She asked the panelists for suggestions on how to break these silos down and encourage different parts of the academic community and the private sector to think more holistically about the issues and solutions.

Tilman responded that, based on his experience, the only way to get people with different backgrounds to collaborate is to gather them in the same place. Architecture or geography, he said, “ends up being intellectual destiny.” He described how at his university, he had a math professor across the hall from him, an economist down the hall, and a historian neighbor

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

as well. He encouraged finding such opportunities to enable regular interaction. He added that in many disciplines, working groups are formed when some sort of formal funding mechanism brings people together four or five times per year. A similar working group encompassing the diversity represented at this workshop could make great progress, he asserted. He cautioned, however, that the first few meetings would be dedicated to simply finding out how to communicate effectively.

Building on Tilman’s response, Fanzo observed that there are many ways to think about “place.” She suggested that the global framework of the SDGs is another type of place, one where the world has been meeting and where a universal framework of action around sustainable development for the next 15 years has been constructed. She stressed not only that the development of the SDGs brought every country to the table, but also that the agreement reached was more collective than was the case for the Millennium Development Goals, with donors really rallying behind the SDGs. Now, she noted, countries are making their own SDG plans, but with different priorities. For example, Nepal, being a land-locked country, is not focusing as intensely on the SDG related to life under water. Countries also are basing their priorities on what they can feasibly do within the next 10 years. According to Fanzo, however, almost every country has prioritized SDG 2: end hunger, achieve food security and improved nutrition, and promote sustainable agriculture.

Drewnowski suggested yet another strategy for breaking down silos, one that operates at what he described as a micro level. He reported that the University of Washington recently approved an undergraduate major in food systems, to be administered by the School of Public Health in collaboration with the School of Business, the School of Law, the College of Engineering, the College of the Environment, and the College of Built Environments. The new major is serving as a mechanism for bringing people from different disciplines and sectors together, in some cases for the first time, all working toward population health. Drewnowski is hoping that the faculty from these different schools and colleges will come together initially to talk about the undergraduate curriculum, but eventually will discuss research and joint projects and grants.

Rose added that beyond finding ways to work together either in a place or on a specific project, as Fanzo and Tilman had discussed, or ways to study together, as Drewnowski had described, it is also important to convey the need for a certain humility to students—that what they study or what they know is not everything. It is vital, he stressed, for students to understand that there are important issues beyond their disciplinary knowledge and that they need to respect other people’s disciplines and talents.

In addition, Rose emphasized the importance of not just working together but also playing together if people are to get along with one another.

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×

As an example, he cited dinners or receptions after workshops such as this, where people have the opportunity to see each other as people, not just professionals. Doing so, he argued, makes it easier to overcome the hurdles that exist in the face of disagreement, misunderstanding, or differing objectives.

Springmann echoed Rose’s call for play and added that tolerance is also important. He encouraged talking to one other, asking questions about what drives people in other disciplines or sectors, and being tolerant of different views.

Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page123
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page124
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page125
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page126
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page127
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page128
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page129
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page130
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page131
Suggested Citation:"6 Concluding Discussion." National Academies of Sciences, Engineering, and Medicine. 2019. Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/25192.
×
Page132
Next: References »
Sustainable Diets, Food, and Nutrition: Proceedings of a Workshop Get This Book
×
Buy Paperback | $60.00 Buy Ebook | $48.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

On August 1 and 2, 2018, the National Academies of Sciences, Engineering, and Medicine hosted a public workshop in Washington, DC, on sustainable diets, food, and nutrition. Workshop participants reviewed current and emerging knowledge on the concept of sustainable diets within the field of food and nutrition; explored sustainable diets and relevant impacts for cross-sector partnerships, policy, and research; and discussed how sustainable diets influence dietary patterns, the food system, and population and public health. This publication briefly summarizes the presentations and discussions from the workshop.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!