dominant schizogene widespread throughout the population, which would function as a necessary, but not sufficient, condition for schizophrenia. The schizogene would manifest on the cellular level throughout the central nervous system and should be observed as a functional control aberration called hypokrisia. Cells exhibiting hypokrisia should contribute to a characteristic pattern of impaired integrative signal processing across multiple neural circuits in the brain, which Meehl termed "schizotaxia". In response to typical rearing environments and social reinforcement schedules, this neural aberration should invariably lead to a collection of observable behavioral tendencies called "schizotypy". Schizotypy indicators would include neurological soft signs, subtle differences in language usage ("cognitive slippage"), and effects on personality and emotion. Meehl believed many people in society exhibit signs of schizotypy as a result of the schizogene without showing signs of schizophrenia. Schizophrenia would only occur when individuals are carrying other non-specific genetic risk factors ("polygenic potentiators") relevant for traits such as anhedonia, ambivalence, and social fear. These additional traits would be more likely expressed under stress (e.g., trauma) and inconsistent social schedules from parents. Given these combinations of conditions, decompensation from schizotypy to schizophrenia would result. Meehl's dominant schizogene theory had a substantial influence on subsequent research efforts. His theorizing increased interest in longitudinal study of individuals at risk for psychosis and family members of people with schizophrenia who may be carrying the schizogene. Meehl's descriptions of schizophrenia as largely a neurological phenomenon and schizotypy as a genetically based risk factor for schizophrenia have been supported. However, researchers have not uncovered strong evidence for a single schizogene, and instead believe the genetic risk for schizophrenia is better explained by polygenic combinations of common variants and rare genetic mutations. Taxometrics With the help of several colleagues, Meehl developed multiple statistical methods for identifying the presence of categorical groupings within biological or psychological variables. Meehl was a critic of the checklist ("polythetic") structure used to categorize mental illnesses in diagnostic manuals such as the DSM-III. Although many DSM-defined psychiatric syndromes can be reliability identified in clinical settings, Meehl argued that the categorical nature of mental illnesses assumed by these diagnoses (i.e., a person is either sick or well) should be tested empirically rather than accepted at face value. Meehl advocated for a data-driven approach that could, in the words of Plato, "carve nature at its joints", and determine when it is most appropriate to conceptualize something as being categorical or