AbstractBlatt's (1900) theory on the two primary dimensions in personality—interpersonal relatedness and self—definition—was applied to the study of loneliness during the transition to university. Participants were 176 students (84 males and 92 females) who completed the Depressive Experiences Questionnaire (DEQ) at the beginning of First‐year university (time 1) and the UCLA Loneliness Scale (trait and state versions) at the beginning and at the middle of first‐year university (time 2). A subsample of students (n= 74) also completed Sharabany's Intimacy Scale at time 2. Trait loneliness was accounted for by higher levels of Self‐Criticism (SC) and lower levels of Efficacy (E). Change in state loneliness from time t to time 2 (i.e., overcoming state loneliness) was predicted by lower Self‐Criticism and higher Efficacy. In the relationship with an intimate partner, Self‐Criticism negatively predicted frankness, sensitivity, and trust, whereas Dependency positively predicted attachment, giving, and trust. The centrality of self‐criticism in vulnerability to loneliness and in lack of intimacy is discussed, and directions for future research on loneliness and personality styles are suggested.