Two studies are reported in this thesis that were designed to examine the concurrent and longitudinal relationships between psychosocial factors (trust beliefs, loneliness, social integration provisions and negative life events) and academic achievement during the first year of study at Keele University. Three mechanisms were examined: (a) the transfer of knowledge comprising trust beliefs as a factor promoting the acquisition of knowledge and thus academic achievement, (b) peer integration and support comprising trust beliefs in peers as a factor promoting social integration/support and thus academic achievement, and (c) trust beliefs as a buffer to stress comprising trust beliefs as a buffer to life stressor which fostered academic achievement. In the first pilot study (Study 1) 133 undergraduates and in second main study (Study 2) 331 undergraduates completed measures of trust beliefs in peers, trust beliefs in lectures (Study 2 only), generalised trust beliefs, loneliness, social integration provisions and life events. The students' academic achievement was assessed by marks and withdrawal. The measures were administered to the undergraduates, in part, or in total, across two times during the course of the first year of university. The findings of Study 2 demonstrated that, in support of the transfer of knowledge mechanism, trust beliefs in lecturers were concurrently associated with marks. Gender moderated the longitudinal relations found in Study 2. Consistent with the peer integration and support mechanism, females' trust beliefs tended to predict increases, social integration predicted increases. and social loneliness predicted decreases, in marks and withdrawal from university. Males tended to show contrary patterns, however, including the finding that their trust beliefs in lecturers predicted decreases in marks. The fmdings failed to yield clear support for trust beliefs as a buffer to stress mechanism with marks, however lower generalised trust and negative life events did predict withdrawal from university. Consistent with previous research, loneliness predicted withdrawal from university. The findings yielded evidence that trust beliefs and other psychosocial factors (e.g., social integration for females, and global loneliness) potentially affect academic achievement in the first year of university but that trust in a particular target (i.e., lecturers) by males may undermine academic achievement.