The aim of this work is to study why children aged 6-7 do not like other classmates. The article goes in depth in the rationale and definition of each category of reasons for disliking proposed by García Bacete, Marande, Carrero and Musitu (2017), and in the meaning of specific reasons, so  that we can identify more accurately similarities and differences in the constant comparisons reason-reason, reason-category and category-category. This has led to the construction of a complete mapping of the reasons and a guide to facilitate an integrated way of understanding and classifying the reasons in eight categories: aggressive behaviors, dominance behaviors, problematic social and school behaviors, inconvenience to well-being, personal identity, social identity, lack of exchanges and “do not know / no answer”. Although some changes did emerge, the outcome reinforces the original taxonomy. A definition for each category, as well as theoretical basis and representative examples, are provided. The conclusion is that the motives for disliking are diverse and usually not put on display, that they have a group basis and reveal failures in inclusion. Finally, guidelines for prevention and intervention in classrooms are offered.