Christopher Barrington-Leigh suggests in his essay that despite messages to the contrary, it is quite possible to live both a happy and an ecologically sustainable life. A growing body of empirical research has actually tested this hypothesis empirically, as I’ve reviewed in a forthcoming article.¹ Specifically, a growing number of studies have investigated how measures of subjective well-being (SWB, including happiness, life satisfaction, and hedonic balance) are correlated with people’s engagement in pro-ecological behaviors (PEBs, including recycling, eating locally, political activism, etc.).

The earliest systematic empirical demonstration that SWB and PEBs are positively correlated occurred in 2005; since then, findings from at least thirteen different studies spanning several nations and tens of thousands of subjects have revealed a consistent significant positive correlation between people’s SWB and their engagement in PEBs. While these correlations are not overly strong, the fact that they are consistently positive across multiple samples and means of measurement provides direct support for Barrington-Leigh’s assumptions.

Of course, correlational data cannot yield causal conclusions, and so in my forthcoming article, I reviewed the evidence for three different explanations for why SWB and PEBs are positively correlated.

First, some work suggests that when people engage in PEBs, they are likely to satisfy inherent psychological needs for autonomy (choosing one’s behaviors), competence (feeling effective), and relatedness (feeling connected to others). Such need satisfaction, in turn, is known to promote SWB. Thus, it may be that engaging in PEBs increases people’s SWB.

The second explanation flips the first, suggesting that feeling happy increases engagement in PEBs. While there is little direct evidence confirming this hypothesis, substantial correlational and some experimental evidence makes it clear that when people are feeling happy (vs. neutral or unhappy), they are more likely to engage in pro-social behaviors. Of course, most PEBs have a pro-social component, suggesting that the causal arrow may flow from SWB to PEBs.

Third, it may be that the correlation is due to some “other variables.” In my forthcoming article, I review three possible candidates: (a) the extent to which one prioritizes intrinsic values (for personal growth and relationships) over extrinsic values (for money, image and status); (b) how mindful one is (i.e., how focused a person is on accepting and attending to one’s momentary experiences); and (c) whether one has made a choice to work less and lead a more voluntarily simple lifestyle. Each of these three variables has been empirically associated with both greater SWB and more engagement in PEBs, suggesting that each could potentially explain the documented positive correlation.

Thus, while this growing empirical literature supports the possibility that a happy, sustainable lifestyle is possible, the policies and interventions that might best be implemented depend on explaining the association. For example, if engaging in PEBs causes SWB, then policy should focus on helping people experience greater need satisfaction when they are engaged in PEBs. If, on the other hand, SWB causes PEBs, then policies should be designed to improve people’s SWB in the hopes that they will then engage in more PEBs. Finally, if values, mindfulness, and downshifting are the true drivers of both SWB and PEBs, then policy and intervention efforts should be focused on those variables instead of directly on PEBs or SWB themselves.

1. Tim Kasser, “Living Both Well and Sustainably: A Review of the Literature, with Some Reflections on Future Research, Interventions, and Policy,” Philosophical Transactions of the Royal Society A: Physical, Mathematical, and Engineering Sciences (forthcoming 2017).