Final answer:
The Moreland and Beach (1992) study exemplifies the principle of similarity, which states that people tend to be attracted to others who are similar to themselves.
Step-by-step explanation:
The basic principle of attraction exemplified by the Moreland and Beach (1992) study is the principle of similarity. This principle suggests that people are more likely to be attracted to and form relationships with others who are similar to themselves, whether it be through shared interests, values, cultural background, or other commonalities. The study highlights how similarity can influence attraction in relationships, suggesting that shared characteristics can increase interpersonal attraction and the likelihood of relationship formation.