The notion of “birds of a feather flock together” points out that similarity is a crucial determinant of interpersonal attraction. Studies about attraction indicate that people are strongly attracted to look-a-likes in physical and social appearance (“like attracts like”). This similarity is in the broadest sense: similarity in bone-structure, characteristics, life goals, ethnicity and appearance. The more these points match, the happier people are in a relationship (Folkes, 1982, Wilson et al., 2006).
The lookalike effect plays an important role called self-affirmation. A person typically enjoys receiving confirmation of every aspect of his or her life, ideas, attitudes and personal characteristics and it seems that people are looking for an image of themselves to spend their life with. One of the basic principles of interpersonal attraction is the rule of similarity: similarity is attractive. It is this underlying principle that applies to both friendships and romantic relationships. There is a high correlation between the proportion of attitudes shared, and the degree of interpersonal attraction. Cheerful people like to be around other cheerful people and negative people would rather be around other negative people (Locke & Horowitz, 1990).
According to Morry’s attraction-similarity model (2007), there is a lay belief that people with actual similarity produce initial attraction. Perceived similarity develops for someone to rate others as similar to themselves in on-going relationship. Such perception is either self-serving (friendship) or relationship-serving (romantic relationship). Theodore Newcomb (1963) pointed out that people tend to change perceived similarity to obtain balance in a relationship. Additionally, perceived similarity was found to be greater than actual similarity in predicting interpersonal attraction. A 2004 study, based on indirect evidence, concluded that humans choose mates based partly on facial resemblance to themselves.
Similarity in different aspects
Findings suggest that interpersonal similarity and attraction are multidimensional constructs (Lydon, Jamieson & Zanna, 1988), in which people are attracted to others who are similar to them in demographics, physical appearance, attitudes, interpersonal style, social and cultural background, personality, interests and activities preferences, and communication and social skills. A study conducted by Newcomb (1961) on college dorm roommates suggested that individuals with shared backgrounds, academic achievements, attitudes, values, and political views typically became friends.
The matching hypothesis proposed by sociologist Erving Goffman suggests that people are more likely to form long standing relationships with those who are equally matched in social attributes, like physical attractiveness, as they are. The study by researchers Walster and Walster supported the matching hypothesis by showing that partners who were similar in terms of physical attractiveness expressed the most liking for each other. Another study also found evidence that supported the matching hypothesis: photos of dating and engaged couples were rated in terms of attractiveness, and a definite tendency was found for couples of similar attractiveness to date or engage. Several studies support this evidence of similar facial attractiveness. Penton-Voak, Perrett, and Peirce (1999) found that subjects rated the pictures with their own face morphed into it as more attractive. DeBruine (2002) demonstrated in her research how subjects entrusted more money to their opponents in a game play, when the opponents were presented as similar to them. Little, Burt, & Perrett (2006) examined similarity in sight for married couples and found that the couples were assessed at the same age and level of attractiveness.
A speed-dating experiment done on graduate students from Columbia University showed that although physical attractiveness is preferred in a potential partner, men show a greater preference for it than women, but other studies show otherwise. Moreover, other than investigation the effect of physical looks on interpersonal attraction, quality of voice that can improve interpersonal attraction was also observed. Two studies were done. For the first study the spotlight, subjects, had 25 female students from a university whereas there were four male target people from a different university. The level of attraction of voice and physical look of the target people was ranked by the subjects. The level of attraction of voice and physical look had their own separate results on interpersonal attraction. For the next study, there 62 subjects, 20 males and 42 females, from a university and there 16 target students, 8 males and 8 females, from a different university. The outcomes of the first study were actually replicated. Hence, cheerful, gentle voices, minimal voiced pitch plus a little scale of vocal pitch tend to result in a greater personal attraction.
According to the ‘law of attraction’ by Byrne (1971), attraction towards a person is positively related to the proportion of attitudes similarity associated with that person. Clore (1976) also raised that the one with similar attitudes as yours was more agreeable with your perception of things and more reinforcing she/he was, so the more you like him/her. Based on the cognitive consistency theories, difference in attitudes and interests can lead to dislike and avoidance (Singh & Ho, 2000; Tan & Singh, 1995) whereas similarity in attitudes promotes social attraction (Byrne, London & Reeves, 1968; Singh & Ho, 2000). Miller (1972) pointed out that attitude similarity activates the perceived attractiveness and favor-ability information from each other, whereas dissimilarity would reduce the impact of these cues.
The studies by Jamieson, Lydon and Zanna (1987, 1988) showed that attitude similarity could predict how people evaluate their respect for each other, and social and intellectual first impressions which in terms of activity preference similarity and value-based attitude similarity respectively. In intergroup comparisons, high attitude similarity would lead to homogeneity among in-group members whereas low attitude similarity would lead to diversity among in-group members, promoting social attraction and achieving high group performance in different tasks (Hahn & Hwang, 1999).
Although attitudinal similarity and attraction are linearly related, attraction may not contribute significantly to attitude change (Simons, Berkowitz & Moyer, 1970)
Social and cultural background
Byrne, Clore and Worchel (1966) suggested people with similar economic status are likely to be attracted to each other. Buss & Barnes (1986) also found that people prefer their romantic partners to be similar in certain demographic characteristics, including religious background, political orientation and socio-economic status.
Researchers have shown that interpersonal attraction was positively correlated to personality similarity (Goldman, Rosenzweig & Lutter, 1980). People are inclined to desire romantic partners who are similar to themselves on agreeableness, conscientiousness, extroversion, emotional stability, openness to experience (Botwin, Buss, & Shackelford, 1997), and attachment style (Klohnen & Luo, 2003).
Interests and activities
Activity similarity was especially predictive of liking judgments, which affects the judgments of attraction (Lydon, Jamieson & Zanna, 1988). Lydon and Zanna (1987, 1988) claimed that high self-monitoring people were influenced more by activity preference similarity than attitude similarity on initial attraction, while low self-monitoring people were influenced more on initial attraction by value-based attitude similarity than activity preference similarity.
According to the post-conversation measures of social attraction, tactical similarity was positively correlated with partner satisfaction and global competence ratings, but was uncorrelated with the opinion change and perceived persuasiveness measures (Waldron & Applegate, 1998).
When checking similar variables they were also seen as more similar on a number of personality characteristics. This study found that the length of the average relationship was related to perceptions of similarity; the couples who were together longer were seen as more equal. This effect can be attributed to the fact that when time passes by couples become more alike through shared experiences, or that couples that are alike stay together longer (Zajonc et al, 1987).
Reasons of spouse similarity
Social homogamy refers to “passive, indirect effects on spousal similarity” (Watson et al., 2004, p. 1034). The result showed that age and education level are crucial in affecting the mate preference. Because people with similar age study and interact more in the same form of the school, propinquity effect (i.e., the tendency of people to meet and spend time with those who share the common characteristics) plays a significant impact in spousal similarity.
Convergence refers to an increasing similarity with time. Although the previous research showed that there is a greater effect on attitude and value than on personality traits, however, it is found that initial assortment (i.e., similarity within couples at the beginning of marriage) rather than convergence, plays a crucial role in explaining spousal similarity.
Active assortment refers to direct effects on choosing someone similar as self in mating preferences. The data showed that there is a greater effect on political and religious attitudes than on personality traits. A follow-up issue on the reason of the finding was raised. The concepts of idiosyncratic (i.e., different individuals have different mate preferences) and consensual (i.e., a consensus of preference on some prospective mates to others) in mate preference. The data showed that mate preference on political and religious bases tend to be idiosyncratic, for example, a Catholic would be more likely to choose a mate who is also a Catholic, as opposed to a Buddhist. Such idiosyncratic preferences produce a high level of active assortment which plays a vital role in affecting spousal similarity.
In summary, active assortarity plays a large role, whereas convergence has little evidence on showing such effect.
Effects of similarity on interpersonal attraction
Similarity has effects on starting a relationship by initial attraction to know each other. It is showed that high attitude similarity resulted in a significant increase in initial attraction to the target person and high attitude dissimilarity resulted in a decrease of initial attraction (Gutkin, Gridley & Wendt, 1976; Kaplan & Olczak, 1971). Similarity also promotes relationship commitment. Study on heterosexual dating couples found that similarity in intrinsic values of the couple was linked to relationship commitment and stability (Kurdek & Schnopp-Wyatt, 1997).
The model of complementarity explains whether “birds of a feather flock together” or “opposites attract”.
Studies show that complementary interaction between two partners increases their attractiveness to each other (Nowicki and Manheim; 1991). Complementary partners preferred closer interpersonal relationship than non-complementary ones (Nowicki & Manheim,1991). Couples who reported the highest level of loving and harmonious relationship were more dissimilar in dominance than couples who scored lower in relationship quality. (Markey & Markey (2007)).
Mathes and Moore (1985) found that people were more attracted to peers approximating to their ideal self than to those who did not. Specifically, low self-esteem individuals appeared more likely to desire a complementary relationship than high self-esteem people. We are attracted to people who complement to us because this allows us to maintain our preferred style of behavior (Markey & Markey (2007), and through interaction with someone who complements our own behavior, we are likely to have a sense of self-validation and security (Carson, 1969).
Similarity or complementarity?
Principles of similarity and complementarity seem to be contradictory on the surface (Posavac, 1971; Klohnen & Mendelsohn, 1998). In fact, they agree on the dimension of warmth. Both principles state that friendly people would prefer friendly partners. (Dryer & Horowitz, 1997)
The importance of similarity and complementarity may depend on the stage of the relationship. Similarity seems to carry considerable weight in initial attraction, while complementarity assumes importance as the relationship develops over time (Vinacke, Shannon, Palazzo, Balsavage, et-al, 1988). Markey (2007) found that people would be more satisfied with their relationship if their partners differed from them, at least, in terms of dominance, as two dominant persons may experience conflicts while two submissive individuals may have frustration as neither member take the initiative.
Perception and actual behavior might not be congruent with each other. There were cases that dominant people perceived their partners to be similarly dominant, yet in the eyes of independent observers, the actual behavior of their partner was submissive, in other words, complementary to them (Dryer 1997). Why do people perceive their romantic partners to be similar to them despite evidence to the contrary? The reason remains unclear, pending further research.
Social exchange theory
People’s feelings toward a potential partner are dependent on their perception of rewards and costs, the kind of relationships they deserve, and their likelihood for having a healthier relationship with someone else. Rewards are the part of a relationship that makes it worthwhile and enjoyable. A cost is something that can cause irritation like a friend overstaying his welcome. Comparison level is also taken into account during a relationship. This suggests that people expect rewards or costs depending on the time invested in the relationship. If the level of expected rewards are minimal and the level of costs is high, the relationship suffers and both parties may become dissatisfied and unhappy. Lastly, the comparison of alternatives means that satisfaction is conditional on the chance that a person could replace the relationship with a more desirable one.
The evolutionary theory of human interpersonal attraction states that opposite-sex attraction most often occurs when someone has physical features indicating that he or she is very fertile. Considering that one primary purpose of conjugal/romantic relationships is reproduction, it would follow that people invest in partners who appear very fertile, increasing the chance of their genes being passed down to the next generation. This theory has been criticized because it does not explain relationships between same-sex couples or couples who do not want children, although this may have something to do with the fact that whether one wants children or not one is still subject to the evolutionary forces which produce them.
Another evolutionary explanation suggests that fertility in a mate is of greater importance to men than to women. According to this theory, a woman places significant emphasis on a man’s ability to provide resources and protection. The theory suggests that these resources and protection are important in ensuring the successful raising of the woman’s offspring. The ability to provide resources and protection might also be sought because the underlying traits are likely to be passed on to male offspring. Critics of this theory point out that most genes are autosomal and non-sex-linked (Gould, et al.)
Evolutionary theory also suggests that people whose physical features suggest they are healthy are seen as more attractive. The theory suggests that a healthy mate is more likely to possess genetic traits related to health that would be passed on to offspring. People’s tendency to consider people with facial symmetry more attractive than those with less symmetrical faces is one example. However, a test was conducted that found that perfectly symmetrical faces were less attractive than normal faces. According to this study, the exact ratio of symmetric to asymmetric facial features depicting the highest attraction is still undetermined.
It has also been suggested that people are attracted to faces similar to their own. Case studies have revealed that when a photograph of a woman was superimposed to include the features of a man’s face, the man whose face was superimposed almost always rated that picture the most attractive. This theory is based upon the notion that we want to replicate our own features in the next generation, as we have survived thus far with such features and have instinctive survival wishes for our children. Another (non-evolutionary) explanation given for the results of that study was that the man whose face was superimposed may have consciously or subconsciously associated the photographically altered female face with the face of his mother or other family member.
Increased female attraction to men in relationships
A 2009 study by Melissa Burkley and Jessica Parker of Oklahoma State University found that 59% of women tested were interested in pursuing a relationship with an “ideal” single man (who was, unknown to the women, fictitious). When they believed the “ideal” man already was in a romantic relationship, 90% of the women were interested in a romantic relationship.
Breaking upRelationship breakup is the ending of a relationship whether it’s a friendship or romantic relationship. There are several reasons that a relationship may come to an end. One reason derives from the equity theory. If a person in the relationship feels that the personal costs of being in the relationship outweigh the rewards there is a strong chance that he/she will end the relationship. Break ups may also occur when the rewards outweigh costs due to guilt and shame.