Customer citizenship behaviours are important for a sustainable customer-brand relationship, yet little is known about the effect of psychological contract breach on citizenship behaviours. From the perspective of psychological contract theory, this research examined the impact of psychological contract breaches on customer citizenship behaviours through the mediating mechanism of psychological contract violation in the customer-brand relationship. Experiments were used to assess the effect of two types of psychological contract breaches on customer citizenship behaviours. The results show that the negative effect of a relational contract breach differs between the dimensions of citizenship behaviours. A relational contract breach has direct and indirect negative effects on recommendation behaviours and helping behaviours, but it does not affect voice behaviours. A transactional contract breach directly and negatively influences recommendation behaviours, but it has no effect on voice behaviours. A transactional contract breach indirectly increases helping behaviours through psychological contract violation. Psychological contract violation partially mediates the effect of a transactional contract breach on customer recommendation behaviours and fully mediates the effect of a relational contract breach on helping behaviours. These findings generate managerial implications for firms aiming to maintain sustainable customer-brand relationships.

Investigating the contributing factors of career adaptability has always been an important topic in the field of vocational psychology research. From the perspective of person-environment interaction, this study introduced the role accumulation theory into the researches of career adaptability. Using a sample of 379 Chinese college students (mean age = 20.36 years, SD = 1.67), a model of role accumulation affecting college students’ career adaptability was constructed, and the parallel mediating mechanisms of self-efficacy and social support were also discussed. Participants filled out questionnaires regarding role accumulation, self-efficacy, social support, and career adaptability. The results of structural equation modeling (SEM) showed that: (1) Role accumulation positively predicted career adaptability in college students; (2) Role accumulation also indirectly predicted career adaptability through self-efficacy and social support. The present study is the first to validate the psychological pathways linking role accumulation to career adaptability via self-efficacy and social support. The contribution of this study to the literature is to provide a new perspective that can clarify the predictors of career adaptability. In addition, for educational administrators and career practitioners, targeting role accumulation is valuable for developing college students’ career adaptability.