Behavioural genetics, also commonly referred to as behaviour genetics, is the field of study that examines the role of genetic and environmental influences on behaviour, with subspecialties focused on human behavioural genetics and animal behaviour genetics. Behavioural genetics is a field that uses genetic methodologies to understand the nature and origins of individual differences in behavior. 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 genetic association studies or family studies including the twin study or adoption study. In animal studies, breeding, transgenesis, and gene knockout techniques are common. Psychiatric genetics, epigenetic research on behaviour, and genetic research in neuroscience are related subfields within behavioral genetics.