Abstract: In this article the authors set a goal to define the relationship between the level of bilingualism and individual personality traits of University students. The object of the research is bilingualism as an indicator of academic success of University students in English combined with one's self-assessment of his or her actual and desired levels of the native and foreign language. The subject of the research is the best age for starting to study a foreign language and individual psychophysiological (peculiarities of brain interhemispheric relations) and psychological (personality traits and values, and intellectual abilities) features of University students. To diagnose the self-development competence the author has used a questionnaire and bilingualism competence as an indicator of academic success. To diagnose biological properties the authors have used an original method of motor screening, to diagnose personality traits the authors have used the Sixteen Personality Factor Questionnaire (16PF) of Raymond Cattell (Form C), to diagnose personal values they have used the AHL 4.2 method and to diagnose the general level of intellectual abilities the authors have used Raven's Progressive Matrices. The authors have carried out correlation and determinant analysis for a group of students with different interhemispheric connections and compared their physiological properties to their personality traits and values and academic success. The hypotheses made by the authors have been proved. The results demonstrate that bilingualism competence of University students has a psychological determination. The earlier the age when a child starts to learn a foreign language is, the higher his or her scores in foreign language tests are. Students with a dominating left hemisphere who received Cs for their English tests have a lesser level of compliance with rules and are more rigid and oppressive. Ambidextrous students are more conforming with the rules and usually need an average level of intellectual abilities to be successful in a foreign language. Right-brain students do not demonstrate any significant differences in their personality traits and values.