These questions are clearly related with the well-known saying: “Birds of a feather flock together”. In order to answer these questions, we analyzed the difference in absolute value of the marks obtained in the different exams by students who sat in adjacent chairs, taking into account the number of times they sat together. The result, summarized in Figure 1, is overwhelming: those students who formed steady pairs (14 times or more throughout the year) got marks with a difference in absolute value lower than one tenth. Clearly, this chart shows that the more times two students sit together, the more similar their marks are. To validate this result we performed the Mantel test studying the relation between the number of times two students sit together and their marks. If we only consider theory groups, then we get a Pearson Product Moment Correlation of 0.16, which shows a low positive relation. This means that the relation exists, but other factors must have influence on it. If we consider laboratory groups, then we get a Pearson Product Moment Correlation of 0,34, which is significantly higher. This is a quantified evidence that the influence of a classmate (which is sharing the computer with you) in the lab is much higher that his influence in the theory lectures.
