What is Confirmation Bias?
What is confirmation bias? It’s the “tendency to search for, interpret, favor, and recall information in a way that confirms one’s preexisting beliefs or hypotheses.” Because of confirmation bias, even the most intelligent people sometimes end up putting together the most absurd arguments, with the most unassailable confidence in their validity. Confirmation bias is the reason why Raymond Damadian, inventor of the first MR (Magnetic Resonance) Scanning Machine, is a young earth creationist. Confirmation bias is one of the reasons why many meat-eaters are incapable of a rational conversation with vegans…
A friendly conversation
Talking about veganism with non vegans is tricky: the conversation gets easily and rapidly polarized, sarcasm quickly kicks in and there’s often not much space left for an honest conversation (it’s often tricky with vegans as well, but for different reasons…). For some reasons, today the subject came up a few times and I had an open chat with a few colleagues on the subject of veganism and its implications. I’ll report my (biased?) recollection of some of the arguments which were purported against veganism. tl;dr yes, they are those arguments…
A painful beginning…
Plants feel pain!
This is false, as prof. Daniel Chamovitz explains in this course for the Faculty of Life Sciences of the Tel Aviv University. Plants do not have nocireceptors, and even if these were identified in the future, plants do not have a frontal cortex, and are therefore incapable of any subjective processing of the information these could possibly pass on. Plants do feel mechanical stimulation, and they are capable of complex information processing and complex interactions with their environment, but they are not capable of suffering.
Of course this explanation is not enough when you have preemptively decided that plants do suffer, so this is what happens at this stage of the conversation by virtue of confirmation bias:
- the anti-vegan googles “plants suffer”
- the anti-vegan picks the first result where somebody claims that plants suffer
- the anti-vegan mentions the article and celebrates victory saying that bacon is delicious. Checkmate vegans
What follows is typically some reference to the marvelous complexity of plants, maybe pointing to this wonderful TED speech in which prof. Stefano Mancuso discusses the capacity plants have of processing and memorizing information. (of course they are ready to dismiss instantly your rebuttal when you point out what prof. Stefano Mancuso says about eating meat vs eating plants in an interview with the Italian newspaper Repubblica: “I am almost vegetarian. For one kilo of meat you will need 1600 kilos of plants, so it is always better to eat plants“)
Besides, what could possibly be the evolutionary explanation of pain for plants, if they can survive the removal of a large amount of their own biomass, they are cognitively incapable of associating pain with potentially harmful situations, and they are unable to move in order to avoid them if they happen again (see Evolutionary and behavioral role of pain)? No answers were given.
But that was just the beginning. Let’s move on to the next argument:
Imagine that one day scientists will prove that plants suffer like animals, or even more than animals. Then what would you do? Now you couldn’t eat animals and you couldn’t eat plants. Boom! Veganism is destroyed, check mate vegans.
This is another common pattern: introducing a hypothetical scenario in which having a plant based diet is impossible, or “plants suffer more than animals”, and argue from there that veganism is an incoherent proposition. Other popular examples are: what would you do in a desert island where the only thing you can eat is rabbits? What would you do in a tribal prehistoric society in which there’s no alternative to meat eating? You can try to explain that there is no moral dilemma if there is no choice, and that necessity changes how an act should be evaluated morally, but the argument will be dismissed, and maybe commented with some jokes about how succulent steaks are. Or you can say that rather than starve to death you would even eat human flesh, but that doesn’t mean that cannibalism is morally justified. In that case, they might say: “I would rather starve to death” (which is easy to say when you’ve never crashed in the Andes like this guy). In any case, meat eaters prefer to imagine hypothetical scenarios rather than facing the basic question vegans pose: why should I exploit and kill animals in Europe in 2019, when I can live in in perfect health and happiness without exploiting and killing animals? The reason is simply indifference towards animals, but they surely won’t admit that (and here is where they take distance from industrial farming and claim that humane slaughter is not an oxymoron).
Environment and deforestation
Another argument against veganism was the following:
If everybody went vegan a lot of extra land would be needed to produce their food, and this would have tragic effects in terms of deforestation and environmental impact.
This is factually false. It is obviously more efficient to eat plant based food directly, rather than feeding plants to animals in order to eat their dismembered carcasses. Research on the field is quite clear on the subject: in the study The opportunity cost of animal based diets exceeds all food losses from Oxford University (March 2018) it is showed how a vegan shift would increase the US food supply by a third – eliminating all losses due to conventional food waste and feeding all current Americans plus about 390 million more. Without meat and dairy consumption, global farmland use could be reduced by more than 75% – an area equivalent to the US, China, European Union and Australia combined – and still feed the world. The Economist covered the publication of this study with some eloquent infographics, which explain why direct consumption of plant food is more efficient (which means it would require less land).
Another study, this time published in June 2018, investigates real data about the impact of farming on the planet (superseding previous analysis based on mathematical models), and the conclusions are unequivocal: the researcher who lead the study (Joseph Poore, University of Oxford) declared: “A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use. It is far bigger than cutting down on your flights or buying an electric car, as these only cut greenhouse gas emissions.” Prof. Poore was not vegan before beginning the study but he is vegan now.
Need more? This study published in July 2018 reinforces the idea that a plant based shift is what our planet needs. The authors say: “Our analysis finds no nutritional case for feeding human-edible crops to animals”.
Need more? Let’s see what researchers comment on the Lancet (studies are referenced and linked in the page): “Much evidence has shown that plant-based diets have both health and environmental benefits. Therefore, incorporation of sustainability in the dietary recommendations would require inclusion of advice to replace livestock products with plant-based alternatives.”
Ok, what about deforestation? A 2016 study from the Institute of Social Ecology (University of Natural Resources & Life Sciences, Vienna) analyzed the relation between dietary choices, global food supply and deforestation. The result is summed up in this article, which reports the words of the authors: “If the world’s population followed a vegan diet, all combinations of parameters, even those with lowest yield levels and low cropland expansion, would be feasible”.
The results are unequivocal; the friends of the “Truth or Draught” page collected a lot of resources explaining why.
It’s also worth mentioning that the 2019 Global Environment Outlook of the United Nations reaches the same conclusions: “Reducing overall meat consumption as well as providing alternatives to conventional livestock production (eg through plant-based meat alternatives) would substantially reduce the agricultural land-use footprint”. Yes: the planet definitely needs more vegans.
Proteins!!!
I know a person who was vegan and was weak and without stamina. People need proteins in meat, vegan diets are insufficient to satisfy human nutritional needs, especially for those who practice sport…
There are many medical institutions and associations of doctors specialized in human nutrition which have destroyed the myth that a properly planned plant based diet is lacking in proteins (or any other nutrients). Let’s go through a few of them.
Association of Dietitians of Canada
“Anyone can follow a vegan diet – from children to teens to older adults. It’s even healthy for pregnant or nursing mothers. A well-planned vegan diet is high in fibre, vitamins and antioxidants. Plus, it’s low in saturated fat and cholesterol. This healthy combination helps protect against chronic diseases. Vegans have lower rates of heart disease, diabetes and certain types of cancer than non-vegans. Vegans also have lower blood pressure levels than both meat-eaters and vegetarians and are less likely to be overweight.“
British NHS
“With good planning and an understanding of what makes up a healthy, balanced vegan diet, you can get all the nutrients your body needs.“
Source: https://www.nhs.uk/live-well/eat-well/the-vegan-diet/
The association of UK Dietitians (BDA)
“Well planned vegetarian diets can be nutritious and healthy. They are associated with lower risks of heart disease, high blood pressure, Type 2 diabetes, obesity, certain cancers and lower cholesterol levels.”
Note: The article refers to several types of vegetarian diets, including the vegan option.
Source: https://www.bda.uk.com/foodfacts/vegetarianfoodfacts.pdf
American Academy of Nutrition and Dietetics
It is the position of the Academy of Nutrition and Dietetics that appropriately planned
vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide
health benefits for the prevention and treatment of certain diseases. These diets are
appropriate for all stages of the life cycle, including pregnancy, lactation, infancy,
childhood, adolescence, older adulthood, and for athletes. Plant-based diets are more
environmentally sustainable than diets rich in animal products because they use fewer
natural resources and are associated with much less environmental damage. Vegetarians and vegans are at reduced risk of certain health conditions, including ischemic
heart disease, type 2 diabetes, hypertension, certain types of cancer, and obesity. Low
intake of saturated fat and high intakes of vegetables, fruits, whole grains, legumes, soy
products, nuts, and seeds (all rich in fiber and phytochemicals) are characteristics of
vegetarian and vegan diets that produce lower total and low-density lipoprotein
cholesterol levels and better serum glucose control. These factors contribute to reduction of chronic disease. Vegans need reliable sources of vitamin B-12, such as fortified
foods or supplements.
Myth: Vegetarians and Vegans Have a Hard Time Getting Enough Protein
As meat has become synonymous with protein, many consumers struggle to identify non-meat sources of this dietary building block. But adequate protein needs easily are attained through a well-planned diet. And plant-based protein typically contains more fiber and less saturated fat, factors that are cornerstones of a heart-healthy diet. There are many versatile plant-based sources of protein that fit into a healthy eating plan: legumes (beans, lentils, peas and peanuts), soy products, whole grains, nuts, seeds and (for lacto-ovo vegetarians) low-fat or fat-free dairy and eggs.
Italian Society of Human Nutrition
Well-planned vegetarian diets that include a wide variety of plant foods, and a reliable source of vitamin B12, provide adequate nutrient intake. Government agencies and health/nutrition organizations should provide more educational resources to help Italians consume nutritionally adequate vegetarian diets.
Note: The study collects both lacto-ovo-vegetarian diets and vegan diets under the definition of “vegetarian diets”; the study and the conclusions apply to both types of diets (including the vegan one)
Source: https://www.nmcd-journal.com/article/S0939-4753(17)30260-0/fulltext
American Heart Association “Circulation” journal
“many people are afraid to follow healthful, pure vegetarian diets—they worry about “incomplete proteins” from plant sources. A vegetarian diet based on any single one or combination of these unprocessed starches (eg, rice, corn, potatoes, beans), with the addition of vegetables and fruits, supplies all the protein, amino acids, essential fats, minerals, and vitamins (with the exception of vitamin B12) necessary for excellent health. To wrongly suggest that people need to eat animal protein for nutrients will encourage them to add foods that are known to contribute to heart disease, diabetes, obesity, and many forms of cancer, to name just a few common problems.“
Source: https://www.ahajournals.org/doi/10.1161/01.CIR.0000018905.97677.1F
… and the Huffington Post 😀
Ok, this is not a scientific publication, but the author does a very good job in explaining how people “hang on to notions from a 1970s diet fad that’s a “complete” waste of time.” Give it a read!
Source: https://www.huffingtonpost.co.uk/entry/vegetarian-protein-complete-meat_n_5a90357ae4b01e9e56bb3224
End game
After this conversation, the non vegan contributors to the discussion were commenting about “drooling over some tasty fat meat”, sincerely convinced that their arguments were solid.
Checkmate vegans!
