Heritability Practice Questions below, bars represent correlation in personality
ID: 199737 • Letter: H
Question
Heritability Practice Questions below, bars represent correlation in personality character trait values between identical In the figure /monozygo along the y-a tic twins (black bars) and fraternal /dizygotic twins (white bars). Trait correlations are given xis. Numbers along the x-axis represent the heritability of each personality trait. C 1.0 0.8 0.8 04 02 O 0.0 O 0.22 0.46 0.42 0.51 0.40 0.38 0.22 0.50 0.52 1. Look at the trait correlations for processing speed. What could account for the relatively high correlation in trait values for both types of twins, despite relatively low heritability (0.22)? 2. If you were to separate identical twins at birth and raise them in different environments which of the above traits would likely retain the highest correlation in trait values between the separated twins? Hint: use comparison of heredity and trait correlation values to support your answer.Explanation / Answer
1.
Normally, identical twins share their genetic makeup by 100 percent while fraternal twins share their genetic makeup only by 50 percent. But, twins share aspects other than the genetic factors such as uterine environment, education, parenting style, culture, wealth, community. Though they both have a low heritability of processing speed trait, the shared environment in which they grew up and the unique environment that helps in shaping their behavior must have been the same for both. Hence, the environmental influence is stronger on both the twin types that might have brought closer correlation values against processing speed trait.
2.
If the identical twins are separated and grown in different environments, there is a possibility of three traits to retain the same or nearer correlation values. They include extraversion, verbal reasoning, and general intelligence. These three traits have the heritability values as 0.51, 0.50 and 0.52 respectively. Firstly, their heritability can keep up the trait expression to more than 50%. The rest of the trait expression is dependent on the environment in which they are made to grow. The general intelligence trait is more likely to get retained with similar correlation value even after the identical twins are separated and grown. Next comes verbal reasoning. Both these traits have higher correlation values along with higher heritability. So, they both are more likely to get manifested in the identical twins when grown separately.