Final answer:
The statement is false; the Minnesota Twin Study included both identical and fraternal twins and studied the genetic and environmental factors influencing their personalities.
Step-by-step explanation:
The statement that The Minnesota Twin Study conducted its research only on identical twins, not fraternal twins is False. The Minnesota Study of Twins Reared Apart included both identical and fraternal twins, with a specific focus on the genetic and environmental influences on their personalities. The study involved 350 pairs of twins, both identical and fraternal, and involved twins who were raised apart as well as together. It found that identical twins, regardless of whether they were raised together or apart, showed remarkable similarities in their personalities. These findings underscore the significance of genetics in shaping aspects of our personalities, although the environment plays a role as well.
It's also important to note that the twins in the studies had varied upbringings, which speaks to the complexities involved in the nature versus nurture debate. Limitations of such studies included the fact that the twins might actually be misclassified as identical rather than fraternal (sample errors), the small sample sizes that are often a challenge in twin research, and the potential differences in socialization that must be considered. Also, correlational research in these areas is constrained in the sense that causation cannot always be established.