In the Minnesota study on reunited twins, many of the twins had similarities in facial gestures, nervous tics, voice quality, political beliefs, job histories, hobbies, and favorite foods. Explain whether heredity or environment account for these similarities

Question

What will be an ideal response?

Answer 1

Answer will include that for several decades, psychologists at the University of Minnesota have been studying identical twins who grew up in different homes. Medical and psychological tests reveal that reunited twins are very much alike, even when they are reared apart. They may even be similar in voice quality, facial gestures, hand movements, and nervous tics, such as nail biting. Separated twins also tend to have similar talents. If one twin excels at art, music, dance, drama, or athletics, the other is likely to as well, despite wide differences in childhood environment. However, political beliefs, jobs, most hobbies, and favorite foods would depend mainly on the environment, which can be relatively similar since these twins were the same age and gender and lived in the same historical times and were exposed to the same influences. In fact, unrelated individuals of the same age can often have numerous similarities. Once these twins were reunited, they would be very motivated to seek out similarities, unlike unrelated people. The twins would pay more attention to similarities than to any differences, therefore, illustrating the confirmation bias. Studies of twins make it clear that heredity has a sizable effect on each of us. Thus, it seems reasonable to conclude that heredity is responsible for about 25 to 50 percent of the variation in many personality traits. However, the same figures imply that personality is shaped as much, or more, by environment as it is by biological predispositions. Each personality, then, is a unique blend of heredity and environment, nature and nurture, biology and culture.