It is plausible that also the effects of trait affect on PEB may be mediated by other factors, including environmental concern (EC) and perceived consumer effectiveness (PCE). Hence, the aim of this paper is to investigate both the direct and indirect influences of trait affect on PEB through EC and PCE, which are key to systematic behaviours towards the environment. 2. Research background and hypotheses Axelrod and Lehman (1993, p. 153) define PEB as those "actions that contribute to the preservation and/or conservation of the environment". More recently, Stern (2000, p. 408) defined environmentally significant behaviour as "behaviour that has a positive impact on the availability of materials or energy and that positively alters the structure and dynamics of ecosystems or the biosphere". These concepts include actions aimed at avoiding damaging, or rehabilitating, the environment, which can be performed individually or collectively, and which impact directly or indirectly upon it. Following the pioneering work of Gardner and Stern (1996), and similarly to Stern (2000), Lee, Kim, Kim and Choi (2014) classify such actions into three broad categories of PEB: green purchases (the purchase of recycled goods or non-toxic substances), good citizenship (the minimisation of energy consumption, water conservation, along with the reduction of waste production and promotion of recycling), and environmental 4 activism (environmental group membership). In line with Milfont and Duckitt (2004, 2010) and Zhao, Gao, Wu, Wang and Zhu (2014), this study approaches PEB as being comprised of both green purchases and good citizenship behaviour, as detailed in the methodology. 2.1 Affect and pro-environmental behaviour Forgas and George (2001) argue that individuals' thinking and behaviours take place in an affective context, and that it is through cognition that the latter influences individuals' judgments and behaviours. Affect has most commonly been structured around a positive and negative valence (e.g., Thoresen et al., 2003). Positive affect (PA) concerns the extent to which individuals describe themselves as feeling joyful, energetic, alert, enthusiastic or fully concentrated. Negative affect (NA) comprises emotions such as fear, anxiety and sadness (Watson, Clark, & Tellegen, 1988). Early research suggested that individuals high in PA process negative information in a superficial way (Isen, 2008). More recently, a considerable amount of research has proved otherwise (e.g., Isen, 2008). These works have shown that PA enhances thoroughness in processing both positive as well as negative information (Aspinwall, 1998). In this context, individuals scoring higher on PA tend to "approach their environment with more favourable expectations, and display a stronger willingness and enthusiasm to seek out and actively engage in various life events" (Kuiper, McKee, Kazarian, & Olinger, 2000, p. 480). Conversely, individuals with higher levels of NA tend to perceive the world surrounding them in a negative manner (Kuiper et al., 2000), and...