Il ruolo dell’Influenza normativa e dell’orientamento valoriale biosferico nella predizione dei comportamenti di mobilità sostenibile

The thesis is composed of three studies, which are part of a larger PhD research project concerning sustainable mobility behaviours and their psychological determinants. These studies are focused in particular on the role of the normative influence and biospheric values orientation on transport behaviours. The research’s main context is the hinterland of the city of Cagliari, and its public transport modality. One of the main focuses is on the changes caused by the extension of the light railway line (“Metro Cagliari”) which passes through the area. The main aims of the three studies are: exploring the effects of normative influence on behaviours concerning urban mobility; studying the influences of biospheric value orientation on transport behaviours; detecting and comparing the role of specific motivations and feedbacks (related either to personal, community or environmental consequences) in promoting these behaviours. 1. The focus group The first study presents a preliminary exploration of issues such as the motivations and perceptions of citizens on public transport and its usage. It also analyses the use of private cars and alternative means of transport, such as those shown in literature (Tertoolen, Van Kreveld, & Verstraten, 1998; Steg, 2005; Gardner & Abraham, 2007), through two focus groups, in which participants are assigned to based on their most frequent travel mode used (car drivers & alternative transport users). Data which emerged from the focus groups show the centrality of public transport in the representations of both groups: car users see public transport as insufficient for their needs, whereas the alternative transport users positively view (but at the same time critical) public transport, considering it a “step ahead in the future”. Car users also, however, stated that they would use public transport, but they avoid doing so because of the “logistical problems” related to transport mobility in Cagliari. Another interesting aspect emerged in both groups is related to the symbolic function of car ownership and car usage, with particular reference to the status that results from the latter. Results are thoroughly discussed within the thesis. 2. The survey study The correlational study has the general purpose of exploring and verifying relationships at various levels between different psychosocial constructs and proenvironmental behaviours. In particular, we detected the role of constructs such as those included in the TPB (Ajzen, 1991) and in the VBN (Stern et al., 1999), and the Social Norms (Cialdini, Kallgren, & Reno, 1991), in predicting the choices of sustainable modes of transport. The correlational study has the following objectives: - to analyse the motives underlying the individual choices of sustainable mobility; - to verify the relationship between type of concerns and beliefs orienting pro-sustainable mobility. In order to reach these goals, a questionnaire was developed and then submitted to 342 residents of the Cagliari metropolitan area. The questionnaire includes measures such as motivations/beliefs on mobility choices, (based both on the findings from the focus groups and on literature, i.e. altruistic, biospheric, egoistic, economic beliefs, etc.); concerns about the consequences of environmental issues (Environmental Motives Scale: Schultz, 2000); proenvironmental transport behaviours (adapted from Schultz & Zelezny, 1998); items of the scale of Universal Values (Schwartz, 1992); social norms (Fornara, Carrus, Passafaro, & Bonnes, 2011) and moral norms (Abrahamse & Steg, 2009). Structural Equation Modelling analysis with the R Stat package Lavaan (Rosseel, 2012) was performed in order to find a good-fit model which is consistent with the theoretical framework. We found a direct influence of moral norms (consistently with VBN Theory) and social norms on our target behaviours, i.e. use of public buses in the city, use of trains and buses for travelling in the metropolitan area, use of the light rail “Metro Cagliari”. In our model, different types of Awareness of Consequences influence different kinds of norms. Moreover, in line with other studies (Hopper & Nielson, 1991; Bratt, 1999; Hunecke, Blöbaum, Matthies, & Höger, 2001), the injunctive norm appears as an antecedent in the formation of moral norms. Another interesting finding, in line with literature, shows that different kinds of concerns, which spark from opposite points of view (environmental vs personal concern) have a correlation between them: this can be coherent with the idea that individuals can show kinds of concerns which may appear as opposite, because people can be concerned about consequences of an environmental issue both for themselves and for the environment. This can be due to the different degree of inclusion in the Self of the objects “myself”, “other people”, and “environment”. In line with the VBN Theory, Universal values influence general proenvironmental beliefs (here measured through the Environmental concern): we found a (positive) relationship between the Self-Transcendence values and the Egoistic dimension of the Environmental concern. This result is in line with a previous study (Stern & Dietz, 1994), which showed how different types of values can affect different attitudes (e.g., Self Transcendence values were positively related to Egoistic consequences). This is also consistent with the relationship between opposite concerns, as reported previously. Finally, the Self-Transcendence values directly influence both Biospheric/Moral and Egoistic awareness of consequences/motivations related to the use of public transport, in line with what found by Stern and Dietz (1994). 3. The experiment The experiment is based on the same theoretical framework of the survey study. The main purposes of the experimental study are: • to verify the influences of scenario conditions based on different feedbacks about transportation behaviours (i.e., personal consequences, consequences for the biosphere, the behaviour of other people and about how much other people positively evaluate the use of public transport); • to verify if there is a congruence between the pre-existing value orientation (e.g., Self-Transcendence) and concern (i.e., Biospheric or Egoistic) of participants with their response to the different feedbacks (e.g., Self-Transcendence congruent to Biospheric concern and Biospheric feedback), and if such congruence correlate the behavioural intention oriented towards public transport; Hypotheses will be discussed in depth within the thesis. The experimental design was implemented by means of a questionnaire including the manipulation of the experimental variable (i.e., the framing of the scenario, including the five different modalities summarized below) and the measure of the other variables. Participants are 100 students from the University of Cagliari, who were randomly assigned to the five different scenario conditions. Each experimental condition conferred a different message describing the consequences of choosing a public/alternative. The messages were: a) Biospheric message about consequences for the environment, b) Egoistic message about consequences for the individual, c) Descriptive normative message about how many people use public transport, d) Injunctive normative message about how other people value the use of public transport, and e) a control condition represented by a blank page. The questionnaire includes also a different version (i.e., with a different number of items) of the measures used in the survey study. The results don’t show an effect of the manipulation of the independent variable. This is probably due to the characteristics of the message (e.g. with a video message or a brochure it can result more efficient) or to the small number of subjects for every condition (since the study is a sort of pilot study). However, using the proxy measured variables of the manipulated variables (i.e. the two Concerns and the Social Norms), Biospheric Concern shows an influence toward the intention in behaving proenvironmental (such behaviours as using bike, public transport). At the same time the injunctive norm shows its effect in promoting the intention to avoid the usage of a private car. Interaction effects between the Biospheric Concern and Egoistic Concern (both measured variables) show an interesting dynamic: individuals who are highly concerned about the consequences on themselves show no significant difference in behavioural intention both when they are much or little concerned for the environment. At the same time those who are little concerned about consequences on themselves show a significant difference between who is much or little concerned for the environment. The latter result questions Environmental Concern’s structure, connected to the Self’s structure (i.e. Arnocky et al., 2007). The interaction between Injunctive Norm and Biospheric Concern has an “additive effect “on behavioural intentions in the high Injunctive Norm condition. This gives a hint on how situational influence works on individuals who are already concerned for the environment, and at the same time it can be related to the Environmental Concern formation, as happens to Values (Andersson & Von Borgstede, 2010; Bamberg et al., 2007; Hopper & Nielsen, 1991; Minton & Rose, 1997; Tronu et al., 2012). Further discussion about results of each study, first separately and then in an organic perspective, together with their possible applications, will be discussed in the thesis.