Final answer:
According to the Minnesota Study of Twins Reared Apart, identical twins are likely to have very similar personalities due to their genetic identity, making Ruth and Ramona, identical twins, the most probable pair to show the greatest similarity in personality.
Step-by-step explanation:
Identical Twins and Personality Similarity
When considering who is likely to show the greatest similarity in personality, we look at genetic makeup and environmental influences. According to the Minnesota Study of Twins Reared Apart, identical twins have very similar personalities, even when raised in separate environments.
This is because identical twins develop from the same fertilized egg and are thus genetically identical. Unlike siblings or fraternal twins, who only share some genes, identical twins share all the same genes, leading to higher similarities in personality. It is important to note, however, that individuals are influenced by both their genetic predispositions and their environments, which can lead to differences over time, despite the genetic similarities.