According to the psycho-lexical approach in the taxonomy of individual differences, those interpersonal differences, which are the most important for social functioning of individual, have been encoded into natural languages. Therefore by analyzing the lexicons of interpersonal differences, it is possible to identify structures of their descriptions. Application of the psycho-lexical approach in the field of psychology of individual differences lead to obtaining the relatively high consistency regarding scientific taxonomy of personality traits. Also models developed on this basis meet the most important criteria of goodness of the psychological structural models. As a result, the accumulation of knowledge about person’s psychological functioning have been intensified. The aim of the article is to present the specificity of lexical studies and their taxonomical potential for social sciences, as well as key threats and limitations, based on experience of previous psycho-lexical research.