Establishing nature preserves and other types of protected areas is one of the most common conservation strategies — and its benefit to the environment is clear. What’s less obvious, though, is how these protected areas affect the human communities nearby.

It’s an important question to consider, not only from a social standpoint, but from a conservation perspective as well: If a local community reacts negatively to the establishment of a preserve — which changes the ways in which they’re permitted to interact with the environment — it may be less likely that the protections will last or be successful in the long run.

Until now, it’s an issue that’s been poorly investigated. But a new study, published Friday in the journal Science Advances, may open the door to a new vein of research aimed at fostering greater understanding of the potential of protected areas for both environmental and human well-being. The study finds that protected areas may actually change the social structure of their associated human communities, inciting both higher degrees of cooperation and competition among community members but with a net outcome that, in the right circumstances, can give a boost to overall social cohesion.

“This creative study provides some of the first experimental evidence showing that both negative and positive interactions can intensify after a cooperatively based human network is formed,” said Brian Silliman, a professor of marine conservation biology at Duke University (who was not involved with the new study) by email.

The new study, led by researcher Xavier Basurto, focuses on the social effects of marine protected areas off the coast of Baja California, Mexico.

“A lot of work has been done on the biological effects of marine protected areas, and much less work has been done trying to understand the effects that they have in fishing communities, or in the communities on the coastline that are influenced by marine protected areas,” said Basurto, an assistant professor of sustainability science at Duke University.

His main interest in the issue, he said, came from a civil society perspective.

“If marine protected areas are having a negative effect, that will undermine the local rural civil society that is needed to help sustain and maintain these marine protected areas over time,” he said. “The likelihood that marine protected areas are going to be there in 100 years — in 1,000 years — is not going to be very high. So that’s why we were very curious to understand what kind of effects marine protected areas have on these communities that depend on them.”

Basurto and his colleagues zeroed in on two marine protected areas in Baja California: Loreto Marine Park, established in 1996, and Cabo Pulmo Marine Park, established in 1995. Both are subject to fairly standard protections, according to Basurto. There’s a core “no-take” zone, in which fishing is not permitted, and then a surrounding area where fishing is permitted under certain restrictions.

In order to understand the social effects these marine parks have on local communities, the researchers conducted a series of experiments, both inside communities subject to the fishing restrictions and in nearby communities with no restrictions. The experiments invited community members to participate in a pair of games that have frequently been used in the past by behavioral economists and social psychologists to study the ways humans interact.

The first game focused on “prosocial” behavior in which individuals sacrifice their own immediate benefit for the public good. Participants were each given an allowance of money and told that they could either keep all of the money or privately donate any amount of it to a public project. For any amount donated by a participant, the game’s moderators would add an additional amount of extra money to the project. At the end of the game, the public pot’s total worth would be divided evenly among the participants. In this case, prosocial behavior would involve donating more of one’s personal money to the public project.

The second game focused on antisocial behavior — in which individuals set out to damage the welfare of others, even at their own personal cost. In this case, participants also started out with a personal allowance. They were then told that they could pay some of that money to reduce another participant’s allowance by a greater amount. Choosing to do so — that is, incurring a personal loss in order to damage another player — would constitute antisocial behavior.

Past studies on prosocial and antisocial behavior have essentially assumed that people fall into one category or the other. This study, however, was different in that it assumed the possibility that members of the same community could be both prosocial and antisocial, depending on the circumstances.

And, in fact, the results showed that communities subject to the restrictions of marine protected areas exhibited a markedly higher degree of both prosocial and antisocial behavior than outside communities. And because both types of behavior were so significant, it appears that the increase in antisocial behavior doesn’t actually undermine the communities’ prosocial tendencies. Another way of looking at the issue is to say that the communities exhibited a high degree of competition — but also a high willingness to cooperate.

The games, themselves, don’t actually explain why these behaviors occur — that’s for the researchers to speculate on. But having worked in Baja California communities for 15 years, Basurto said he has some ideas, which were also supported by interviews with community members during the study.

“This simultaneous cooperation and competition in fishing I think is normal and is part of everyday life,” he said.

In a video released alongside the new study, the researchers interviewed local fisher Fabian Gonzalez, who noted the “friendly rivalry” that exists among community members. “The excitement of fishing for a fisher or captain like myself is in always trying to be the best — and to also be a good friend to everyone,” he said.

The researchers postulate that this balance between cooperation and competition exists even in communities that are not subject to the restrictions of protected areas. It’s just that both behaviors become exaggerated when such restrictions are put in place. The reason likely has to do with the ways protected areas change the social stratification of local communities.

In a coastal community with no fishing restrictions, for instance, most community members are likely to rely on fishing for their livelihoods and are thus all more or less on an even playing field, socially speaking. When a marine protected area is established however, and fishing becomes subject to greater restrictions, some community members may turn to other livelihoods, such as tourism — and may even go on to be more successful than some community members who stuck with fishing.

When these different opportunities open up, it can result in a kind of income inequality in the community that did not exist before, Basurto noted. This phenomenon can drive up competition among the community members. But it can also drive up cooperation.

The games in this particular study included both fishers and non-fishers in the community, and found that both groups exhibited an increase in prosocial and antisocial behavior within the marine protected areas. This suggests that while the different groups may be competing with one another, they also band together when it’s necessary for the sake of the community — and their competition doesn’t prevent them from doing so.

So in this way, a healthy balance between competition and cooperation isn’t necessarily a bad thing. In fact, Silliman — the Duke University marine conservation biologist — said such balances are commonly observed in nature.

“This study led by Basurto indicates that, like natural systems, having intense competitors within a cooperative network are potentially key to its stability,” he noted.

But the intensification of both cooperation and competition in a community may also indicate the emergence of social inequalities, which is an issue policymakers should be careful to take into account when designing protected areas.

“Sometimes marine protected areas are seen as something you only do for the ecology, for the well-being of the [biodiversity], and the social system is not necessarily much considered,” said Örjan Bodin, a researcher on social-ecological systems with the Stockholm Resilience Center. “This study shows that you actually change the fundamental social systems in the community just by the establishment of the marine protected area.”

And if these social systems were to degrade in the future, it could threaten the success of the protected area, Basurto pointed out.

“We can see that in other places where social inequality continues to increase, that could have negative effects on social cohesion and suddenly the antisocial behavior breaks the balance and predominates over prosocial behavior,” Basurto said. “The implications for marine protected areas is that when they’re established attention needs to be paid to issues of social inequality or income inequality as part of the design…so that prosocial and antisocial behavior continues to be in balance, and the future of the biodiversity that’s trying to be conserved is not put at risk.”

Such precautions will also benefit human communities by helping to lessen the social impact of certain policies and prevent harmful inequalities from arising in the first place. Allowing local communities to have a greater voice in the decisions that are made in their regions, as well as making sure adequate social programs are in place to aid the disadvantaged when such policies are enacted, could be a helpful step forward, Basurto said.

Further research will be necessary in different locations and among different types of protected areas to find out if the results can be generalized — but Basurto said he thinks it’s likely the same types of effects occur in different contexts. And Bodin added that this paper could help inform an entirely new line of thinking when it comes to predicting the social and ecological outcomes of establishing a preserve, one that’s hardly been explored before.

“It opens up this new perspective on competition and collaboration,” he said.