The investigation compares argumentative individual complexity written in socio-scientific tasks of university students of Psychology, depending on years of study and the presence/absence of an additional representation system (graphs) of information external. 72 students from the argentine university participated. They gave their opinion about a socio-scientific situation that included arguments for and against it, and a group received additional graphic information. The productions were coded according to: (a) whether it was an argumentative text; (b) the relation to the argumentative texts, the number of arguments, the type of difference of opinion, the argumentative structure, and confirmatory bias; (c) he use of information. The results show a relationship between first-year students and non-argumentative texts and between advanced students and the use of argumentative texts. Both t...