Abstract
Over the century, many studies have proposed an association between madness and kin advantages. The first study focusing specifically on reproductive rates among persons suffering from schizophrenia and their relatives was published in 1959. Currently, there are 62 studies of that kind indexed in the main scientific databases, most of which confirm the existence of kin advantages after one generation. Considering that picture, this brief review explores the data of the most recent study of the kind, in order to discuss the percentage of advantage after two generations. Results: The advantage after two generations is considerably lower than in the first generation, although it should not be dismissed. However, it may be biased by the association between schizophrenia and economic status, since low economic status predicts both increased risks of schizophrenia and higher reproductive rates in several different regions of the world. Furthermore, the importance of de novo mutations, copy number variations and other sporadic genetic (and epigenetic) events, which may take part in the etiology of a significant portion of the cases of schizophrenia, presents an indirect challenge to the hypothesis of kin advantages.
Keywords: Schizophrenia, evolution, reproduction, genetics, social psychiatry
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