This study reports the performance of 419 undergraduate and graduate students on three questionnaires addressing their biodata, social and cultural capitals and personality factors. The statistical analysis of the students' diploma Grade Point Averages (GPAs) and monthly family income (MFI) showed that the GPAs and MFIs of students majoring in English as a foreign language were significantly higher than those majoring in Persian as a first/second language. Among the five personality factors, i.e., Neuroticism, Extroversion, Openness, Agreeableness and Conscientiousness, only the last revealed significant relationships with the eight social factors, i.e., Parental Consultation, Family-School Interaction, Family Support, Extracurricular Activities, Family Relationship, Parent-School Encouragement and Facility, Peer Interaction, and Religious Activities, for both English and Persian students. Conscientiousness, however, correlated significantly only with the GPAs of Persian students (r = 0.21, p <0.01). Similar significant differences were found in the relationships among the GPAs and social factors underlying the social capitals of English and Persian students. Since the highest correlations obtained in the study belonged to different cultural, social and personality factors for English and Persian students, it is argued that learners approach a foreign language as a goal in itself whereas students of native languages employ them to achieve various objectives such as establishing interpersonal relationships through Extroversion and overcoming their Neuroticism through social interactions. The implications of the findings are discussed within the context of foreign language teaching and suggestions are made for future research.