There is empirical evidence in different languages on how the computation of gender morphology during psycholinguistic processing affects the construction of sex-generic representations. However, there are few experimental studies in Spanish and there is no empirical evidence about the psycholinguistic processing of morphological innovations used as non-binary forms (-x; -e) in contrast to the generic masculine variant (-o). To analyze this phenomenon, we designed a sentence comprehension task. We registered reading times, precision and response times. The results show the specialization of non-binary forms as generic morphological variants, as opposed to the generic masculine. The non-binary forms consistently elicited a reference to mixed groups of people and the response times indicated that these morphological variants do not carry a higher processing cost than the generic masculine. Contrary to what classical grammatical approaches propose, the generic masculine does not function in all cases as generic and its ability to refer to groups of people without uniform gender seems to be modulated by the stereotypicality of the role names.