Two decades ago, it would not have been possible for most people to mentally picture the implementation of pro-environmental behaviours in their daily life. This is not the case any more: recent years have witnessed the blooming of sustainable ways of thinking and behaving. Accordingly, humans have become more and more familiar with pro-environmental behaviours. 

This fact triggered our interest in examining the brain reactivity of individuals when they were asked to reflect on the feasibility of adopting specific types of sustainable behaviours in the near future. We observed that reflecting on increasing (“do more”) sustainable behaviours encompasses strikingly different brain network dynamics than does reflecting on decreasing (“do less”) unsustainable behaviours. Critically, increasing sustainable behaviours was rated as being more feasible than reducing unsustainable ones. Hence, our results suggest that encouraging the development of sustainable behaviours (e.g., using public transportation "more") is more efficient than restricting people from unsustainable behaviours (e.g., using the personal car "less").

These findings have direct societal implications, as the climate change crisis is often depicted as an effortful “self-control” challenge. Individuals are indeed encouraged to prevent short-term-oriented behaviours (e.g., overconsumption) and adopt long-term valuable goals (the preservation of the environment and natural resources). Critically, our findings showed that the development of pro-ecological habits should not resolve around the opposition between unsustainable (“bad” habits) and sustainable (“good” habits) conduct, but rather focuses on how and when implementing sustainable behaviours.

Such an assumption is in line with recent theoretical accounts on addictive disorders (i.e., conditions that are often conceptualized within a disease model in which “addicts” are considered as lacking in willpower), which advance that the maintenance of long-term abstinence from addiction-related habits cannot be reached through effortful self-control but rather by recovering interest in actions/activities that allow the individual to find a sense of agency, self-identity, and meaning in life. A comparable dynamic of behavioural change can also be found in other conditions that represent public health concerns (e.g., obesity).

This view has practical implications that could be operationalised across many fields. For instance, in academia, researchers should be encouraged and reinforced when they choose sustainable ways of sharing their scientific knowledge (e.g., by holding online conferences), and not when they decide to restrict or monitor their own travel mode choices (e.g., taking a plane less often).

Related to this aspect, another intriguing observation from our study is that a large part of the sustainable behaviours (depicted in our experimental task) involved healthy lifestyle habits, such as physical activity (e.g., biking, walking, using stairs, using public transportation, gardening). This aspect signals the potential benefit of adopting integrative and translational research programmes to create affordances (i.e., potential actions made available to the individual by the surrounding environment) for increasing humans effectivity in being physically active through pro-environmental habits (for example, by harvesting biomechanical energy while walking, running, or biking).

The implementation of pro-environmental habits should thus revolve around a wider individual-environment system (i.e., linked to motivations that do not necessarily tap into to the protection of the environment) by creating new affordances across a large range of behaviours.

In the meantime, new knowledge should emerge to open innovative avenues for better understanding of how the human mind switches from mere feasibility judgments to actual and persistent engagement with sustainable behaviour and disengagement from unsustainable behaviour.

Article: Brevers D, Baeken C, Maurage P, Sescousse G, Vögele C, Billieux J. Brain mechanisms underlying prospective thinking of sustainable behaviors. Nat Sustain (2021). https://doi.org/10.1038/s41893-020-00658-3