As global environmental concerns continue to mount, it’s no surprise that cities, companies and organizations around the world launch all matter of campaigns, initiatives and educational programs to convince us to be as environmentally-friendly as possible. While personal pro-environmental actions, like walking instead of driving, unplugging devices when not in use and making sure the tap is totally turned off, might not have the biggest impact on the environment, these community-wide and long-term behavioral changes can accumulate to make a major difference. Even though most people understand the benefits of environmental responsibility, however small and simple such actions might be, new research from Japan suggests that how energized and refreshed people feel correlates with how likely they are to actively partake in activities considered good for the environment on a personal level; sleepy people are just too tired.

The intriguing joint study, conducted by The University of Tsukuba’s Naoko Kaida and Institute for Information Technology and Human Factors’ Kosuke Kaida, was designed to “identify the relationships between sleepiness, pro-environmental behaviors and the balance between optimism and pessimism.” Based on the much-researched fact that sleepiness contributes to negative moods, confusion and demotivation, the study’s authors made the logical assumption that sleepy people are less likely to engage in activities, including pro-social behaviors. “From this perspective, identifying psychological factors that influence pro-social behavior, including sleepiness, optimism, and pessimism, is becoming increasingly important in the fields of behavioral research such as behavioral economics and environmental psychology, because human behaviors are not only influenced by rational reasoning, but also by emotions and mood,” explains the research paper. By pro-social behaviors, the researchers mean “individual actions that are intended to improve social conditions and help other individuals,” and explain that actions in favor of the environment are relatively new concept under the pro-social umbrella. “They cover behaviors such as saving energy and reduced consumption of resources, the moderate use of motor vehicles, and nature conservation.”

With this assumption in mind, the research team went about conducting surveys of a random sample of 382 registered voters in Tsukuba City, Ibaraki, Japan, with demographic questions, as well as questions referring to their sleepiness habits, optimism vs. pessimism, and energy conservation habits. For the sleepiness survey, the team used the Epworth Sleepiness Scale which is a subjective, self-reported scale on “sleepiness in everyday situations and its association with other psychological factors and behaviors rather than instant sleepiness at certain times… Respondents were asked to provide their evaluation of sleepiness in eight situations, by using a four-point Likert scale consisting of 0 (would never doze), 1 (slight chance of dozing), 2 (moderate chance of dozing), and 3 (high chance of dozing). Higher scores indicated greater subjective sleepiness.” To assess optimism and pessimism among the respondents, a standard Extended Life Orientation Test was included in the survey, which presents six optimistic statements and nine pessimistic ones and requires answered based on a Likert scale, anchored between 1 (strongly disagree) and 5 (strongly agree). Finally, one simple question was asked to assess the frequency and inclination to perform pro-environmental behaviors – respondents were asked to rate their likelihood to switch off room lights when not in use on a scale of 1 to 6.

Next, the researchers categorized respondents’ optimism/pessimism and pro-environment behavior scores into two groups, based on their sleepiness scores. Perhaps unsurprisingly, the less sleepy respondents were also the most optimistic, and there’s plenty of medical research to support these findings. Meanwhile, people who reported feeling sleepy more often scored higher for pessimism and, crucially, were less likely to switch off unneeded lights. This led the researchers into a second phase of surveys which were designed not only to measure sleepiness but their nightly sleep durations, as well as a more varied set of questions regarding their behavior towards the environment. In study two, “data were collected on participants engagement in the following nine pro-environmental behaviors related to: shopping bags (‘I bring a reusable bag for my daily grocery shopping’), water use (‘I use water sparingly’), electricity use (‘I use electricity sparingly’), reuse (‘I purchase refillable products to allow reuse of plastic containers.’), air conditioner temperature (‘I set the air conditioner at a moderate temperature’), environmentally responsible products (‘I purchase environmentally responsible products whenever they are available’), garbage separation at home (‘I properly separate garbage at home.’) and garbage separation in public places (‘I properly separate garbage in public places.’).

Even with more metrics in place, the sleepier the respondent the less likely they were to engage in pro-environment activities, as less sleepy people: “six out of the nine pro-environmental behaviors examined in Study 2, that is, those related to ‘water’, ‘electricity’, ‘temperature’, ‘products’, ‘home garbage’, and ‘public garbage’ were conducted significantly more frequently by the low sleepiness group than by the high sleepiness group.” And to confirm that the ‘sleepiness’ reported isn’t just laziness, as some may assume, the less environmentally-friendly, sleepier respondents also slept for less time at night, meaning they exhibited true tiredness rather than disengagement was the measure in this study. Meanwhile, the correlations remained the same when demographic differences were taken into consideration, meaning educational levels and wealth made no impact on the likelihood of performing (or not performing) pro-environment actions.

“This suggests that extending sleep duration may be one of the easy and practicable approaches to reduce sleepiness and to facilitate pro-environmental behaviors. Reducing sleepiness may thus let people be prone to pro-environmental activities,” concludes the research paper. With plenty of research that links urban life to insomnia and fatigue, perhaps it’s time public health officials teamed up with environmentalists to encourage more sleep and less waste.