**Hypothesis 2 (H2).** *Materialism has a negative effect on sustainable consumption behavioural intention.*

Past research suggests that influences from the social environment can be exerted by friends, family, and other groups deemed important to a consumer (Gleim et al. 2013). Piligrimiene et al. ˙ (2020) confirmed the indirect positive impact of the social environment (as part of the external group of factors) on green product purchase behaviour. Thus, it is hypothesised that:
