The pioneering research on temperament was conducted decades before the current revolution in genetic research. At the time there was no real way to separate the effects of environment from the effects of genes. Now, however, there is more and more evidence of genetic contributions to various personality traits. Individual differences in sociability and shyness, impulsivity, anger control, and anxiety have all been shown to have a genetic basis. Therefore the concept of a genetically based temperament that is first evident in early childhood and persists into adulthood is supported by current research.