By Clarice Cudischevitch
Simon Levin mixes mathematics, biology and sociology to understand human behavior
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Why do fish swim in schools? How do birds flock so harmoniously? What motivates people not to wear a mask in a pandemic? One of the most fascinating phenomena in life sciences is precisely the conflict between individual and collective behavior. But it’s not exclusive to the biological world. Ecologist Simon Levin extrapolated it to the social sciences to understand the behavior of a particular species: humans.
This is because, although natural selection affects differences between individuals, in nature there is cooperation from the cellular level to different animals. Levin, director of the BioComplexity Center and professor of ecology and evolutionary biology at Princeton University (USA), applies mathematics, his original background, to examine these two contradicting trends.
They are already relatively well known in biology. Due to natural selection, organisms that can survive better are more likely to pass on their properties to their offspring and thus perpetuate their genes. In The Selfish Gene, biologist Richard Dawkins notes that collective behavior, such as flying in a flock, is adopted because it increases the likelihood that a genetic line will survive.
However, when we talk about human interactions, the conversation is more complex. When fish swim in schools for mutual benefit – against predators, for example – collective behavior that is more beneficial to society usually means restricting individual actions. “We have to learn from nature how we can work together,” says Levin.
In mathematics, it is game theory, a technique that modulates the strategic behavior of agents in different situations and makes it possible to understand these relationships. A classic example: if people prioritized public transport over cars, the congestion would decrease and benefit everyone. In this scenario, however, individuals would get out of the car to take advantage of the flow of traffic and re-congest the roads. For the collective, cooperation would be better than selfish individual actions.
This mix of math with sociology and biological influences is useful in understanding the Covid-19 pandemic. Levin, who has studied infectious disease dynamics for more than 40 years, explains that in the case of the coronavirus, we use models that predict the spread of the virus, the differences between patients with and without symptoms, and other aspects that help make you think about strategies. But the social component is missing.
“We see groups who are reluctant to get vaccinated. Why? “Asks Levin. “There are people who refuse to wear masks. China, Japan, and Asia in general are countries that are more open to this type of protection, while others, like Sweden, are resisting. Understanding this is a problem in the social sciences. “
Levin goes further: How are collective decisions made? How are social norms created and maintained? How do individuals interact? One of his current studies aims to understand the dynamics of political polarizations. “People are part of different groups that sometimes overlap. We develop models in which individuals change their minds or migrate from groups due to interactions with other people. “
Such models are also used in international contexts. For example, they not only analyze the relationships between nations, but also the influence of organizations such as the UN and WHO on the decisions and changes in the positioning of the countries.
So many interdisciplinary interventions have resulted in the 79-year-old Levin having a scientific production of almost 700 publications. Doctor since 1964, it is true that the scientist did not start now, but the secret is different.
“I have a wonderful group of students and nothing could happen without them,” he says. “The work is the result of intense collaboration, which is why the effort to train people is so important. The reason I still have students is how much I learn from them and how much they can build. When people work together, they can do so much more. “Here is a successful human example of collective behavior.
Simon Levin will participate in the launch of the quantitative biology and ecology training program in Brazil offered by the Serrapilheira Institute and the South American Institute for Basic Research (ICTP-SAIFR). He will be giving a webinar on March 2nd at 11am. More information here.
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Clarice Cudischevitch is a journalist, communications manager at Instituto Serrapilheira and coordinator of the blog Ciência Fundamental.
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