The nature-nurture debate is interested in contributions of nature (hereditary) and nurture (environment) in individual differences. Nativists (role of nature) stress inherited influences whereas empiricists (environmentalists) believe knowledge is the result of learning and experience. Today, the debate focuses on an interactional approach. This is the belief that both nature and nurture are essential to any behavior and interact in a complex manner; thus supporting the statement ‘nature and nurture interact; both are vital to understanding behavior’.
The main method of studying contributions of hereditary and environment is twin studies. Mz twins share 100% of genes and DZ twin’s share 50%. The rationale is to establish the contribution of inheritance and environment. If MZ twins reared together are more alike then DZ twins reared together then this is due to genetics (e.g. alcoholism). This degree of similarity between twins is expressed as a high concordance rate. Twin studies of IQ and schizophrenia show higher concordance rates for MZ twins – suggesting a genetic influence. Bouchards studies of IQ compared MZ twins even when reared in difference environments. This points to a clear genetic influence. To evaluate the twin studies, MZ twins are more likely to be treated similarly then DZ twins. E.d. they dress the same. This makes it difficult to distinguish the influence of biological or environmental factors. Twins are not likely to be separated at birth and raised in different environments (although it does happen). This means that there is a limited population of people that can be used in this type of twin adoption study. Therefore research is limited using this research.
Unshared environments can explain differences between siblings. A child creates its own