Question

In a personality survey, which set of twins would be expected to score most similarly? (A) Identical twins raised in different homes (B) Fraternal twins raised in different homes (C) Identical twins raised in the same home (D) Fraternal twins raised in the same home

Short answer

Option C: Identical twins raised in the same home

Step-by-step solution

Understanding the Question

The question asks to determine which set of twins would have the most similar scores on a personality survey. To answer this, we need to consider the genetic similarities and environmental factors for each option.

Genetic Similarities

Identical twins share 100% of their genes, while fraternal twins share about 50% of their genes. This means that, genetically, identical twins are more similar than fraternal twins.

Environmental Factors

Twins raised in the same home share the same environment, while those raised in different homes do not. The shared environment can contribute to similarities in personality scores.

Comparing the Options

Given that identical twins share more genetic material than fraternal twins, and that twins raised in the same home share the same environment, identical twins raised in the same home (Option C) would be expected to score most similarly on a personality survey.

Key concepts

identical twins

Identical twins, also known as monozygotic twins, originate from a single fertilized egg that splits into two. This process results in two individuals who share 100% of their genetic makeup. Identical twins often look very much alike and have similar physical traits. Their shared genetic information means they may also share many behavioral and personality traits.
When comparing personality survey scores, identical twins are more likely to have similar results compared to other sets of twins due to their genetic similarities. This likeness is present even if they are raised in different environments, though the environment still has a significant impact.

fraternal twins

Fraternal twins, also known as dizygotic twins, come from two different eggs fertilized by two different sperm cells. As a result, they share about 50% of their genetic makeup, just like any other siblings. Fraternal twins can look quite different from each other and may have varied physical and personality traits.
When considering a personality survey, fraternal twins would generally show less similarity in their scores compared to identical twins. This genetic diversity means their personalities and behaviors can diverge more significantly.

genetic similarities

Genetic similarities play an essential role in determining personality traits. Identical twins, sharing 100% of their genes, tend to have much more in common personality-wise compared to fraternal twins, who share only about 50% of their genes.
This higher degree of genetic overlap in identical twins can lead to closer resemblances in responses to personality surveys. Genetic factors largely influence traits such as temperament, intelligence, and other aspects of personality. Therefore, greater genetic similarities result in more consistent personality characteristics.

environmental influences

Environmental influences encompass all external factors that can affect an individual's development from a very young age. For twins, the environment includes factors such as the home they grow up in, their education, social interactions, and life experiences.
Twins raised in the same home experience similar environments, which often contribute to shared hobbies, values, and personality traits. In identical twins, this shared environment combined with identical genetics often results in the most similar personality survey scores.
On the other hand, twins raised in different environments may develop distinct personalities. This demonstrates how powerful environmental factors can be, either reinforcing or altering the traits determined by genetics.