Minnesota Twin Study
Conducted by:
-Lykken and Bouchard
The Study:-Used all identical twins to compare those that were raised together to those that were raised apart to determine if their personal qualities are determined by environment or genetics.
-Took 56 pairs of monozygotic reared apart (MZA) participate in intensive psychological and physiological tests.
-Twins compared to monozygotic twins reared together (MZT).
The Experiment:
-As much data as possible in this weeklong experiment
-Each twin completed:
o 4 personality trait scales
o 3 aptitude and occupational interest inventories
o 2 intelligence tests
o 1 life history interview, 1 psychiatric interview, and 1 sexual history interview
Results and Significance:
-Degree of similarity is expressed in the table as the “R” values.
-Larger the correlation = the greater similarity
-Logic: if the environment IS responsible for individual differences then MZT twins(grew together) should be more similar than MZA twins.
-Unfortunately this is NOT what researchers found. -These findings indicate that genetic factors account for most of the variation in variety of human characteristics.
-Monozygotic twins raised apart in different settings grew into adults who are extremely similar. Appearance AND in personal psychology.
-There appeared so little affect of environment on identical twin who were raised in the same environment.
-Larger the correlation = the greater similarity
-Logic: if the environment IS responsible for individual differences then MZT twins(grew together) should be more similar than MZA twins.
-Unfortunately this is NOT what researchers found. -These findings indicate that genetic factors account for most of the variation in variety of human characteristics.
-Monozygotic twins raised apart in different settings grew into adults who are extremely similar. Appearance AND in personal psychology.
-There appeared so little affect of environment on identical twin who were raised in the same environment.