What's the problem with using homeopathy against the common cold? It seems harmless. Check your horoscope before leaving home, too. The situation becomes a little more nebulous, however, when trying to treat a serious illness using homeopathic preparations or when a worker loses his job because his birth chart is ''incompatible” with that of his boss.
Often enveloped in an affable aura of harmless curiosity, pseudosciences — beliefs that illegitimately claim the same degree of reliability as science — can perversely harm everyone's lives and also the planet. The danger is revealed, for example, when industries or specific sectors of society, for religious, political or economic reasons, come together to take advantage of the population's low knowledge of how science is done, and also the high level of misinformation present in the virtual environment.
With increasing social polarization, there are more and more politicians and influencers who propagate pseudoscientific or even anti-scientific ideas, using known strategies, which have been improved over the centuries, and which now gain extra effectiveness thanks to the internet and new forms of social interaction.
In his 1995 book "The Demon-Haunted World", CarlSagan offers a “nonsense detection kit”, consisting of eight strategies for critically analyzing claims that purport to be scientific.
Sagan, like other authors, suggests that there are common elements that appear in the discourse and position of pseudoscience propagators. Here, we offer a quartet of indicators:
Negative evidence: when the arguments in favor of an idea are limited exclusively to allegations about errors, real or imaginary, that exist in the ideas of others. Even if everyone else is really wrong, that doesn't mean the option offered is correct. She may even be more wrong than the rest.
Correlation and causation: pointing out that, because one thing varies in a similar way to another, it is caused by the other. This is not always true: there are countless examples of disconnected phenomena that vary in similar ways over some time — for example, from 1999 to 2009 the number of deaths from drowning in swimming pools in the USA followed the same trend as the number of films starring by Nicholas Cage.
Hand-picked examples: present only cases that seem to confirm your ideas. No procedure, strategy or treatment works 100% of the time. When the subject is science, anyone who does not take flaws into account, or hides them when presenting results, is incompetent or dishonest.
Appeal to antiquity: claiming that an idea or procedure is appropriate because it has been used for centuries. History is full of nonsense that has survived the test of generations, from the theory that the Earth is at the center of the Universe to the use of bloodletting to combat infectious diseases.
These tactics are usually accompanied by elaborate language, catchphrases and rhetoric that, directly or indirectly, accuses critics of being part of some great conspiracy. Today, it is not difficult to identify those who systematically use such tools.
And the consequences can be serious. In Brazil, public money is wasted on health treatments that are based only on false correlations, antiquity and cherry-picked examples. Global warming denial and creationism are based on negative evidence. The anti-vaccine movement, fueled by conspiracy theories, leads to the resurgence of diseases.
As, unlike legitimate science, pseudosciences have no commitment to reality, they easily adapt to public preferences and the spirit of the times. This makes them attractive. Escaping this attraction may not be easy, but it is increasingly necessary, for the good of our society.
*Marcelo Knobel is rector of the State University of Campinas (Unicamp)
Carlos Orsi is a journalist and director of the Instituto Questão de Ciência
