This dissertation focused on studying pro-environmental behaviours and examining the influence of motivations on such behaviours. We sought to use different psychometric approaches towards this aim, with the hope of commenting on the advantages and disadvantages of each approach and the information gained within this research context. The dissertation consists of four research projects whereby different methodological approaches were used to examine how motivations might explain variations in pro-environmental behaviours (PEBs).

In the introduction chapter, we outlined a framework for understanding PEBs. We first introduced the concept of motivations – any construct used to capture the ‘why’ behind behaviours – and then reviewed the background literature surrounding the influence of motivations on PEB. We then reviewed other known constructs related to the discussion of motivations and the prediction of PEBs, such as values, attitudes, goals and intentions. We conclude the introduction by justifying the adoption of a framework whereby PEBs are conceptualised as intentional goal-directed behaviours.

In a methodology chapter we provide an overview and relevant background into the methods used within the dissertation. We review the literature surrounding the use of computerised tasks and the concerns around self-report measures, statistical modelling approaches, and the development of measurement scales within psychological research. Each method is discussed in terms of its advantages and disadvantages in how it will allow us to draw conclusions about the power of motivations to help explain variations in PEBs.

In Chapter 4, the research project used an experimental approach where a computerised task was designed to capture recycling behaviour. Recycling behaviour is inherently limited in the feedback or reinforcement, and/or punishment one receives, and it is difficult to reinforce since it is not a simple behaviour but rather one that occurs in response to various cues. Using this task, we examined differences in recycling behaviour across familiar and unfamiliar contexts, considering the given goal to recycle correctly, and investigated if the use of feedback would help support behaviour maintenance towards the goal. Across three studies (N = 530), the results suggested that recycling behaviour patterns in unfamiliar contexts may be more influenced by the changes in sorting rules rather than

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motivations. We discussed the conflicting results and possible challenges of weighing infrastructure demands against considerations of individuals’ interaction with the sorting.

In the Chapter 5 research project, we used a time-series analysis to model longitudinal data. Using a daily diary method, we measured behaviour occurrences and goal importance daily for 3-weeks. While the literature suggests that behaviour performances may impact future mental states (i.e., goals), to our knowledge, this has not been directly tested in an applied setting, nor using multi-level data. We sought to examine a possible dynamic effect between daily goal importance ratings and daily recycling and sustainable consumption behaviours. The results (N = 144) indicated that goal ratings are only predictive of same-day behaviours. Goals and behaviours do not appear to have a dynamic relationship. The results are discussed in line with goal-systems theory with the suggest of the need for future research to replicate the results.

In Chapter 6, the study focused on examining pre-volitions and using a Structural Equation Modelling analysis to examine variations in recycling and sustainable consumption behaviour. We measured pre-volition constructs (i.e., attitudes, norms, perceived behaviour control, and behaviour desire, etc.) and perceived barriers (i.e., wealth, busyness), including a distinction between doing and not doing goals at baseline. Then, recycling and sustainable consumption behaviours were measured over a three-week period using a daily diary method. The results (N =144) suggested that the two behaviours have very different profiles despite both being considered pro-environmental behaviours. We discussed how the findings suggest that recycling may be conceptualised as an incidental behaviour and sustainable consumption may be conceptualised as deliberate, highlighting the importance of considering sustainable behaviours as overlapping yet distinct.

Lastly, in the Chapter 7 research project, the current project aimed to develop a measure of contact with nature that would capture the individual’s experience and improve upon measures of exposure in explaining variations in pro-environmental behaviours. What is currently missing from the literature is support from participant data about interactions with nature that can be reliably classified according to the four typologies – intentional, incidental, direct and indirect. To this end, across three studies (N = 482), we developed a preliminary Experience with Nature scale by identifying intentional interactions with nature supported by participant data. In a fourth study (N = 301), this project then demonstrated that by capturing the individual’s experience, we were able to explain more variations in PEBs compared to exposure to nature alone. The results are discussed in line with the literature about

motivations behind contact with nature and the need to capture the experience in order to improve the prediction of outcomes.

In the final discussion chapter, we combined the results across all studies, providing a nuanced discussion surrounding the power of motivations to explain PEBs. The focus of the discussion is surrounding the methodological advantages and disadvantages of each research project including a critical examination of what each method has allowed us to conclude. We discuss the external validity of the computerised task used in Chapter 4, the benefits of the time-series modelling approach used in Chapter 5, the potential limits of pre-volition models in explaining actual behaviour with respect to Chapter 6, and the limitations of the measurement scale developed in Chapter 7. Overall, this dissertation highlights the important research considerations relevant to each psychometric approach as well as an overview of the challenges related to examining pro-environmental behaviour.