Behavioural genetics, also commonly referred to as behaviour genetics, is the field of study that examines the role of genetic and environmental influences on animal (including human) behaviour. Often associated with the ""nature versus nurture"" debate, behavioural genetics is highly interdisciplinary, involving contributions from biology, neuroscience, genetics, epigenetics, ethology, psychology, and statistics. Behavioural geneticists study the inheritance of behavioural traits. In humans, this information is often gathered through the use of the twin study or adoption study. In animal studies, breeding, transgenesis, and gene knockout techniques are common. Psychiatric genetics is a closely related field.