What causes schizophrenia? The short answer may be "nothing" or more precisely "no one thing." In most cases, schizophrenia is an end result of a complex interaction between thousands of genes and multiple environmental risk factors—none of which on their own causes schizophrenia. Daniel Weinberger, in his classic paper on brain development and schizophrenia (10), entertained the "unlikely" possibility that schizophrenia is "not the result of a discrete event or illness process at all, but rather one end of the developmental spectrum that for genetic and/or other reasons 0.5% of the population will fall into." Over 20 years later, this unlikely scenario is looking more realistic. Schizophrenia is increasingly considered a subtle neurodevelopmental disorder of brain connectivity, of how the functional circuits in our brains are wired. Schizophrenia may in fact be the tail end of a distribution of how the estimated 20 billion neurons and their trillions of synaptic connections in our brains are generated, eliminated, and maintained. Schizophrenia may be the uniquely human price we pay as a species for the complexity of our brain; in the end, more or less by genetic and environmental chance, some of us get wired for psychosis.