Final answer:
The assertion that similarity influences attractiveness is true, as people tend to form relationships with others who are similar to them in various ways. This concept is known as homophily, and the matching hypothesis asserts that individuals select partners based on a perceived equality in attractiveness and desirability.
Step-by-step explanation:
The similarity between two individuals indeed influences how attractive one appears to the other, which supports the true assertion that people are attracted to those who are similar to themselves. This phenomenon, known as homophily, suggests that we are more likely to form relationships with others who share our background, attitudes, and lifestyle. Additionally, the matching hypothesis proposes that people often choose partners who they perceive as being roughly equal in physical attractiveness and social desirability.
Cultural factors also play a significant role in defining what is considered physically attractive, which can lead to regional evolutionary changes in body morphology, known as sexual selection. It is interesting to note that, while physical attractiveness is important, people still tend to choose partners based on similarity rather than seeking the most attractive partner possible.