People tend to choose their life partners or romantic partners based on similarities or correspondence of personal, social, cultural, economic, or psychological characteristics. This trend is one of the fundamental factors influencing the formation and duration of human relationships, as it increases the chances of harmony and understanding between the two parties and reduces the likelihood of future conflicts caused by differences in values or interests. Psychologically, this trend is explained by people feeling comfortable and confident interacting with people who are similar to them in thinking, beliefs, and interests, as similarities enhance self-acceptance and a sense of belonging. Choices based on similarity create a common basis for communication, foster strong emotional bonds, and increase the likelihood of a relationship developing into a long-term commitment. From a sociological perspective, the assortativity hypothesis suggests that relationships based on similarity contribute to the stability of families and societies by reducing differences that can lead to conflict and promoting harmony between shared values and beliefs across generations. Applied research shows that conformity is not limited to superficial traits such as appearance or attractiveness, but also includes intelligence, ambition, religious beliefs, and moral compass. The deeper the similarity, the higher the likelihood of long-term survival and continuation of the relationship.