The article analyzes the arguments used in two distinct moments of the 20th century, to justify the use of biological explanations for conducts considered as socially undesirable. Firstly we refer to studies of hygienists in the early century, whose explanation were centered on the organic and innate character of deviations, then we analyze the recent studies in the neurosciences which try to locate these conducts in inadequate synapses and in explanations related to chemical cerebral deficiencies.
cerebral localization; heritage; biological determinism