Do Biospheric Values Moderate the Impact of Information Appeals on Pro-Environmental Behavioral Intentions?

“Did you know that producing 1 kg of beef causes 13 kg of CO₂ emissions?” Such information is frequently offered in attempts to persuade people to change their behaviors into a more environmentally friendly direction. The rationale for implementing such informational interventions is intuitively appealing: because people will likely fail to act pro-environmentally when they are unaware that their behavior has a detrimental impact on environmental quality, an obvious approach would be to provide information about the behavior’s negative environmental impact [1,2]. Consequently, information-based interventions are still the most frequently used intervention approach to motivate people to change not only environmentally harmful behaviors but also unhealthy or socially problematic behaviors [1,2]. But are information-based interventions actually effective in motivating people to change their behaviors? First research results on this question showed that providing ‘pure’ information alone is not effective [3,4]. According to the existing literature, this finding is not surprising because information has behavioral consequences only if the recipient of the information is motivated to do something with that knowledge [5]. As a consequence of this insight, research subsequently focused on the question of which motivating factors influence the effectiveness of informational interventions on environmentally friendly behaviors/behavioral intentions [1].

Above all, some research findings indicate that personal values are a central motivating factor for environmentally conscious intentions and actions [6,7]. Values reflect relatively stable, general, and desirable goals that are important in and guide peoples’ lives [8]. Values function as standards by which actions, groups, and individuals are evaluated. All basic human values are endorsed, at least to some extent, by all individuals across the world. Yet, individuals differ in how much they endorse and prioritize each value over others. Furthermore, values only indirectly guide peoples’ behaviors [9]. For example, the Value-Belief-Norm (VBN) theory [10] further specifies how values affect behavior via behavior-specific beliefs and norms. In the environmental domain, four types of values appear particularly important: egoistic, hedonic, altruistic, and biospheric values [6,7]. Egoistic and hedonic values focus on goals that primarily benefit oneself: acquiring possessions and status, and pleasure and reducing effort, respectively. Individuals who strongly endorse these two values are typically less likely to engage in pro-environmental actions, because such actions often have some individual costs. On the other hand, altruistic and biospheric values reflect goals that benefit a greater cause than oneself: nature and the environment, or others and society. The more individuals endorse these two values, the more likely they will engage in pro-environmental actions, as such actions typically support these values [6,7]. Particularly, people with strong biospheric values are more likely to be intrinsically motivated to engage in climate actions, as doing so is in line with what they find important. Intrinsically motivated people act without being forced to do so and without receiving external rewards for doing so because they feel good when they act in accordance with their values and experience intrinsic rewards [11,12,13,14]. Because intrinsic motivation comes from within a person, it is self-sustaining and long-lasting, making it a solid source of consistent climate action [6,15].

Based on these findings, it is argued that whether recipients of information appeals consider environmental protection an important personal goal in their lives is crucial for the effectiveness of these appeals (the ‘values-as-moderator hypothesis’) [1]. In other words, it is assumed that the effectiveness of informational appeals is moderated by the extent to which recipients endorse biospheric values (BioVs) [1]. Informational appeals typically explicate the negative environmental consequences of behaviors that people consider convenient and comforting. Following this line of thinking, such impact information should elicit cognitive dissonance if recipients personally care about environmental quality, because it highlights a discrepancy between what recipients freely choose to do and what they personally consider important [1]. However, people who do not consider protecting the environment an important personal goal should not respond to such an informational appeal because they are not experiencing a discrepancy between their values and behavior. Hence, informational appeals should not have an impact on people with weak BioVs. Besides an experimental study conducted by the founders of this assumption themselves [1], we found two other experimental studies providing empirical support for the moderating function of BioVs on the effectiveness of informational appeals. One study found that the strength of BioVs moderates the effectiveness of an informational appeal on participants’ intention to buy bottled water [1]. In another study it was examined whether provision of information on the environmental impact of street lighting affects the acceptability of reduced street lighting levels [16]. As predicted, low lighting levels were seen as more acceptable when information on the environmental impact of street lighting was provided to individuals that strongly endorsed BioVs. Another research group found a moderation effect of BioVs on the power of an informational appeal to save paper [2].

In recent years, the values-as-moderator hypothesis has been extended to socio-normative appeals, that is, appeals that provide information about the BioVs of others. It is assumed that people are more likely to engage in climate actions when they believe other group members strongly endorse BioVs and engage in climate actions. This seems to be the case particularly when members strongly identify with the relevant group and do not strongly endorse BioVs themselves [17,18,19]. These results suggest that communicating that most other group members care deeply about nature and the environment and act accordingly can encourage individuals to take climate action, especially those who are not strongly motivated themselves.

If the values-as-moderator hypothesis is true, it would have important practical implications for the design of appeals to motivate people to show more pro-environmental behavior. In light of this hypothesis, neither informational nor socio-normative appeals would be able to motivate the entire population. Instead, an approach that tailors such appeals to the values prioritized by an individual would be necessary for their persuasive effectiveness: whereas informational appeals should be persuasive for persons with high BioVs prioritization, socio-normative appeals should be persuasive for persons with low BioVs prioritization. Consequently, it was already suggested to use modern technology, for example smart meters, to assess with a short questionnaire people’s value prioritization and then tailor the delivered appeal to their value profiles [2]. However, deriving practical implications with such serious consequences from research results is legitimate only if their validity is based on strong empirical evidence. In our view, however, the empirical evidence for the values-as-moderator hypothesis is currently not very strong. There are only a handful of experimental studies, mainly conducted by one research group from the Netherlands, that aim to explain very simple and low-cost behaviors, such as using bottled water, saving paper, or accepting reduced street lighting. Furthermore, the assumption derived from the values-as-moderator hypothesis that neither informational nor socio-normative appeals are able to motivate the entire population does not match the results of meta-analyses, which point to the general effectiveness of informational and socio-normative appeals: a meta-analysis summarized the results of 92 studies that evaluated the effectiveness of information interventions appealing to the environmental protection motive (e.g., goal setting, self-contrast feedback, environmental information, and public commitment) in influencing energy-saving behaviors [20]. Overall, an average mean effect size of d = +0.50 was determined for these appeals. Based on the results of 91 studies evaluating the effectiveness of socio-normative appeals, an overall average small-to-medium effect size was found (d = +0.32) [21]. These meta-analytic results provide more support for the view that practitioners might use informational and socio-normative measures as effective interventions without considering people’s value prioritization.

In the following, we report the results of two studies aimed at replicating the test of the values-as-moderator hypothesis in two different contexts: the everyday ‘low-cost’ behavior of purchasing (organic) coffee and the more difficult ‘high-cost’ behavior of adopting a heating style that prevents rebound effects after the energetic renovation of an apartment. For each behavioral domain, we developed an informational appeal highlighting the negative environmental consequences of buying conventional coffee or an energy-wasting heating method versus the positive environmental consequences of buying organic coffee or an energy-saving heating method and compared the effect of these appeals to a no-appeal control condition (CG). Furthermore, we also developed a socio-normative appeal inducing participants to imagine that they work in a very environmentally conscious company, where the head of the company and all the fellow workers put a lot of effort into limiting their negative impact on the environment. We compared the effects of the socio-normative appeal with a CG without explicit socio-normative information. Additionally, we asked participants in Study 1 to imagine the target behavior (purchasing coffee) either for their own household vs. for breaks with colleagues at work. This third intervention element was motivated by the assumption that the private versus public nature of the target behavior may be a second moderator of the impact of socio-normative appeals: if neither the enactment nor the consequences of a behavior are known to others, social norms may lose their motivational power [22,23,24]. Consequently, publicness increases, whereas privateness decreases the effect of socio-normative appeals. By randomly assigning participants to experimental conditions using quotas that ensured that an equal number of high BioVs and low BioVs participants were assigned to each appeal condition, we were able to compare the effects of value-congruent (information appeals for participants with high BioVs and socio-normative appeals for participants with low BioVs) and value-incongruent (informational appeals for participants with low BioVs and socio-normative appeals for participants with high BioVs) appeals. In both studies, the importance that participants assigned to BioVs was assessed using a short scale that we explain in the Methods Section of this paper. The novelty of our studies is to test independently and with a sophisticated experimental design the circulating assumptions about the massive impact of BioVs on the effectiveness of interventions to promote pro-environmental behaviors, and furthermore to examine the effects of the level of publicity of an action. In more detail our studies aim to provide an experimental test of the following six hypotheses:

The assumption that BioVs are the central motivating factor for pro-environmental behavior [6,7,15,16,32] is only partially supported by our studies. Only in Study 1, where the dependent variable was the low-cost intention to purchase organic coffee, we found a weak main effect of BioVs on this intention. In Study 2, where the dependent variable was the high-cost intention to reduce rebound effects after energy renovation, we did not find a main effect of BioVs on this intention.

However, in contrast to the values-as-moderator hypothesis and in line with the available meta-analytic findings [20], both studies showed a main effect of informational appeals on the studied intentions. Furthermore, the impact of the informational appeal was stronger in the case of the low-cost organic coffee purchase intention than in the case of the high-cost rebound reduction intention. For the main effect of the socio-normative appeal the finding was similar: In the case of the low-cost organic coffee purchase intention the main effect of the socio-normative appeal was significant, whereas in the case of the high-cost rebound effect reduction intention the socio-normative appeals had no significant main effect. Thus, the fact that heating-related behaviors are normally performed in a private context may be one reason for the ineffectiveness of the socio-normative appeals in Study 2. Summarizing, our empirical results suggest that it is not peoples’ value profiles, but the perceived effort and costs associated with a behavior as well as the public vs. private nature of the context in which the intended behavior will be performed that are of more significance for the effectiveness of socio-normative appeals: in public contexts and for low-cost intentions the impact of socio-normative appeals is stronger than in private contexts or for high-cost intentions. Another point we may discuss is that the reference group (colleagues at work) may have been less relevant in Study 2 than in Study 1. A more relevant group might have been, e.g., other tenants in rented apartments.

From our point of view, the most important finding of the two studies, however, is that they do not support the values-as-moderator hypothesis. Neither in Study 1 nor in Study 2, the interaction effects of BioVs and the two different appeals were significant. Thus, our results do not support the assumption underlying the values-as-moderator hypothesis that the effectiveness of informational and socio-normative appeals depends on the importance participants assign to BioVs. Instead, our results are more in line with the view that informational and socio-normative appeals influence the behavior of people regardless of their value priorities. These results argue against the high influence attributed to values in activating behavior change [1]. In summary, according to our findings, the target behavior and the behavioral context seem to be of much greater importance for the effectiveness of behavioral interventions than individual value expression. Our findings of context-dependent effectiveness of different types of interventions argue for the approach of multimodal interventions that combine socio-normative triggering information with environmental awareness-raising information. Thus, multimodal interventions may be the best option if the goal is to influence the broadest possible range of behaviors toward more environmentally conscious actions.

An important limitation of our study is that we measured only behavioral intentions and not real behavior. Furthermore, despite the advantages of conducting experiments with random assignment to conditions, the experiments have a quite artificial character. Another limitation is that the mean BioVs scores were overall high in both the ‘high’ and the ‘low’ BioVs subgroups. This confirms the assessment that most people around the world regard BioVs as important [7]. But from a methodological point of view, the relatively small difference between the ‘high’ and ‘low’ BioVs subgroups may be a reason why the interaction of BioVs and the interventions was not significant. Another methodological deficit of our studies relates to the fact that, despite the relatively large sample size (>800 in each study), our studies had too little statistical power to detect minimum effect sizes we considered to be practically relevant. In addition, the participants may have guessed the aim of the studies and thereby might have been influenced to respond in a particular way, especially in Study 2.