The primary finding of the Minnesota Study of Twins Reared Apart (MISTRA) was that there is a substantial genetic influence on various traits and characteristics, including intelligence, personality, and behavior.
The study, which was conducted by Thomas J. Bouchard Jr. and his colleagues at the University of Minnesota, aimed to examine the relative contributions of genetic and environmental factors in shaping individuals’ development and outcomes. The researchers studied identical twins who were separated at a young age and raised in different environments, allowing them to assess the impact of genetics versus upbringing on various aspects of their lives.
The MISTRA found that identical twins who were reared apart showed remarkable similarities in numerous traits. For example, they exhibited comparable IQ scores, personality traits, and interests, despite growing up in different households with distinct cultural and environmental influences.
The results of the MISTRA indicated that genetic factors played a significant role in shaping individual differences, suggesting a strong hereditary component for traits such as intelligence and personality. While environmental factors still contribute to an individual’s development, the study highlighted the substantial influence of genetics on various aspects of human behavior and characteristics.
It is important to note that the MISTRA focused on identical twins, who share 100% of their genetic makeup. The findings may not necessarily apply to fraternal twins or non-twin siblings who have a different genetic relatedness.