Adoption studies are one of the classic research methods of behavioral genetics and are an effective technique for assessing the interconnections of genetic and environmental variables in the elicitation of human qualities such as intelligence (IQ) and diseases such as alcoholism. They also compare personality traits and mental disorders. Adoption studies are used alongside twin studies to identify the roles of genetic and environmental variables in the development of drinking issues along with many other diseases in children who were adopted. These studies often include identical twins who are adopted into different families, and they have pinpointed that some traits such as schizophrenia, IQ, criminality and alcoholism are linked to genetics. Adoption studies also usually compare the res