Relationships are subjective; individuals search for partners based on their own personal preferences. There is, however, a plethora of literature pointing to relationships having a complementary or similar dynamic regarding personality, hobbies, background, etc. Here the literature is reviewed for these theories and also a combination of complementary and similar traits in relationships. While all research is legitimate, no conclusion can be made because it cannot and should not be assumed what all individuals look for in a relationship or what relationship dyad is the most successful.
Similar Versus Opposite in Romantic Relationships
Everyone has heard the slogan “opposites attract” in romantic relationships, but more recently “birds of a feather, flock together” has been used to describe similarities in partners. Ample research shows both relationship dyads to be successful. Complementary theorists claim that the relationship is a unit; both partners contribute their own attributes to complete the unit. A couple may have one partner who is extraverted and the other introverted. This dynamic works because the individuals feed off of each other’s strengths and weaknesses. While, similarity theorists claim that partners show more relationship satisfaction when they have more in common because they are able to relate more to each other. These couples share common personality traits, hobbies, backgrounds, etc. With a certain factor in common, the couples have more to relate to. Thus far, there is no concrete answer on which theory is correct. Relationships are highly subjective; analysis of both the complementary and similarity theory show that couples may find satisfaction in a dyad of either of the two
Our society is heavily influenced by relationships that are broadcasted to the public through movies, television shows, and celebrity couples. Popular couples such as Jim and Pam from The Office, Ben and Leslie from Parks and Recreation, and Marshall and Lili from How I Met Your Mother are the epitome of similar couples. Throughout the shows, each couple, respectively, demonstrates similarities in their hobbies, personalities, and world-views. On the other hand, couple John Legend and Chrissy Teigen broadcast their complementarity personalities through social media. Legend is very reserved while Teigen is out-going; the couple has been in a committed marriage for several years now. The dynamic of couples is surely influential to their followers. Followers observe couples with opposite or similar compositions and become inspired to find a partner that embodies a character or celebrity. This rationale is toxic because rather than letting fate bring two individuals together, regardless of composition, people will reject or desire a partner because of factors other than their own preference.
Opposites Attract
To begin, couples who have opposite traits are said to be “complementary.” The traits of thee couples work together to create a cohesive unit, or relationship. Similar to magnets, individuals that lack one trait, will search for a partner with this exact trait. This theory proposes a ying and yang effect. In a study completed by Dryer and Horowitz (1997), college students completed a measure of dominance/ submissive goal tendencies, a Five Factor personality measure, and a problem-solving task. Pairs were randomly assigned between the participants. Pairs were then asked to complete a series of problem-solving tasks and then rate their satisfaction upon completion. Results found that partners who were most dissimilar, such as one partner was dominant and the other submissive, rated highest on satisfaction. The study aligns with the notion that opposites attract in order to create one cohesive unit. Both individuals are able to bring a plethora of skills to the relationship which work in a complementary fashion.
Similarly, the creation of a single unit when a romantic couple has complimentary traits allows for a wide spectrum of strategies regarding goal-pursuit. With the same goal or task at hand, romantic couples were studied regarding their cohesiveness and effectiveness at completing said task. Married couples were assigned an online questionnaire to be completed separately. The questionnaire asked about factors such as goals, trust, affection, and inclusion of other in the relationship. Then, the couples had to complete a goal-oriented task. Overall, partners who had high goal-congruence but complementary style of goal-pursuit reported the highest level of martial satisfaction and most effective goal-completion (Bohns et al., 2013). In this case, the married couples that had opposite styles of completing tasks, were the couples who were the happiest and most effective. Similar to ying and yang, complementary relationships need both partners to be the most successful. The individuals thrive and feed off of each other to create their cohesive unit.
Finally, not only do humans look for romantic partners to be complementary, animals do as well. The giant panda has been known to be difficult to breed in captivity, accounting for its diminishing numbers in the wild. In a recent study, giant pandas were examined for their personality traits using caregiver surveys and tests with toys. Pandas were then strategically paired in hopes of producing cubs. In terms of personality traits, pairing males and females with opposite levels of aggressiveness, excitableness, and food anticipation yielded the most cubs. Males with high levels of aggressiveness, almost “required” their female to have low levels of aggressiveness. Pandas that had similar personality traits did not produce cubs (Martin-Wintle et al., 2017). Results like this have revolutionized how pandas are bred in captivity; they are now paired according to complementary personality traits. Failure to breed successfully could have been due to male and female pandas being too similar. This also applies to human relationships; on occasion couples do not succeed because the individuals resemble each other too much.
Similarity
On the contrary, “birds of a feather, flock together” is used to describe individuals in a romantic relationship, that resemble one another. These individuals may attract because they share the same hobbies, values, religion, personality traits, etc. In a study conducted by Braxton-Davis (2010), 206 college students were asked to complete a survey about what characteristics they look for in a partner. It was hypothesized that the students would report physical attractiveness and similarity as the most desirable. Results indicated that similarity surpassed physical attractiveness in the importance of an individual being desirable. While all college students rated physical attractiveness high, they noted that similarity holds more weight because the dynamic between both individuals is more important than being attractive. ¬Factors such as religion, race, ethnic group, world view, and personality were used to describe similarity. Of these factors, college students ranked personality to be the highest of importance regarding similarity. In theory, extraverted people are more likely to spend time with extraverted people, and vice versa. Individuals are prone to flock to others that are similar to themselves.
When romantic couples are similar to each other in personality, they are more satisfied because they are able to relate to each other more than individuals with different personalities. The current study examines the effect that each individual’s personality has on the relationship. Five factors, actor effect, partner effect, gender, additive effect, synergy, and similarity were evaluated for a total report of each individual’s effect on the relationship. Results simply state that similar couples are happier. Couples were evaluated on personality “superfactors” of positive emotionality, negative emotionality, and constraints. Of the superfactors, when partners were most similar in negative emotionality, they were the happiest. Partners who are able to handle stress, anger, and anxiety the most similarly, report the most satisfaction. Similar positive emotionality and constraint also produced this effect, although not as significant. Also, partners who react positively and manage their impulses in a similar manner, report more satisfaction (Robins, Caspi, & Moffitt, 2000). Individuals play and contribute their own role into the relationship, however, a relationship is a duet. Both partners need to work together to produce a beautiful relationship. In order to achieve this, the partners must be on the same page. Having similar personality traits and emotional responses already gives the couple an advantage because they understand each other.
Following, the phenomena of convergence, or the merging of two individuals in any aspect, can occur in relationships. Individuals, often in the beginning of a relationship, have very separate personalities, but further along, the two individuals begin acting like each other. Research shows that similarity in personality and emotions lead to higher relationship satisfaction in both randomly selected individuals and romantic couples. Individuals paired randomly, dating couples, and newlywed couples all were examined using a questionnaire and observation of interactions. The randomly paired individuals and dating couples without similarity, reported less satisfaction. Additionally, the newlyweds were found to have similarity upon marriage, but then convergence of personality and emotions after an average of 1.5 years. The newlywed couples that converged the most, maintained their satisfaction. However, couples who did not converge their traits, became less satisfied in the relationship (Gonzaga, Campos, & Bradbury, 2007). This being said, similarity of couples yields the most satisfaction. Similarity allows the couple to experience life together, with the same perspective.
As stated beforehand, convergence is the merging of a feature between two individuals. Not only does convergence occur for personality traits, it can occur for physical traits. Long-term couples can blend into each other physically. In a study conducted by Zajonc, Adelmann, Murphy, and Niedenthal (1987), physical features were compared between couples who had just been married, and then measured again after 25 years of marriage. Subjects did not know the couples were married, the task was to predict if they were. At the point of marriage, the couples did not look similar to each other. However, it was determined that after 25 years of marriage, the couples grew physically more similar to each other. The couples were then interrogated. Couples who had the highest reports of similarity, also reported the highest levels of happiness (p. 336-346). Spending years upon years with a spouse has shown to produce a convergence in physical appearance. Being more similar to their spouse, clearly has the effect of increased happiness. Individuals can unconsciously learn their partners facial expressions and begin to replicate it. When the couple is using the same expressions and emotions, they are on the same page. There would be no discrepancies, leading to higher happiness.
Lastly, couples can find similarity in outwardly-expressed factors such as their personality, physical attractiveness, and worldview. However, couples can also be similar in a more internal fashion, with their life goals and implicit motives. Life goals are a state of being that an individual strived for, while implicit motives are needs or motivating factors that the individual may not be even conscious of. Heterosexual couples in Germany were recruited to take questionnaires and written evaluations regarding life goals and implicit motives. The difference in scores was taken for all measures; the lower the score, the more similar the couples were in each aspect. Results found that life goals contained the most similarity between partners (Denzinger, Backes, & Brandstätter, 2018). With this data, we can assume that couples who have similar life goals, attract more frequently to each other. Having similar life goals is beneficial because couples can understand, support, and motivate one another as they work towards their goals.
Interplay of Similar and Opposite
Debunking whether an individual wants a partner similar or complementary to them is not a clean-cut task. The answer may be that individuals want a mix, or both. While an individual can desire a partner who is similar to them in background, they can also desire their partner to be complementary in personality. This hypothesis was tested by Dijkstra and Barelds (2008); students off of a college dating site were asked to test their personality traits and rate their desired partner’s personality traits. Lastly, students were explicitly asked if they prefer their partner opposite or similar to them. While the students rated themselves and their desired partner to be similar to each other, when asked explicitly, students desired complementary partners. It was determined that the students desired a partner similar in personality, but complementary for other traits such as intelligence, age, and religion. Evolutionary psychology states that mates first look for partners on the basis of similarity social status and wealth. With this pool of potential partners based on similarity, then the mates choose upon left over complementary traits (p. 595-602). This being said, partners may not simply look for a mate who is their “twin” or complete opposite. Mates may have a combination of traits, both similar and complementary, that the individual picks to be suitable for them.
Thus far only courting patterns for humans has been discussed, however, the same principles apply to animals, specifically monkeys. Monkeys have been researched to show both similar and complementary styles of mate choice. In a study conducted by Capitanio, Blozis, Snarr, Steward, and McCowan (2017) five hundred rhesus monkeys were attempted to be paired based on personality traits. At the average age of one hundred days old, the monkeys were removed from their mothers and placed in an individual testing room. Researchers observed the monkeys for 25 hours. In the 25 hours, the temperament, behavioral responsiveness, activity, location, and emotions were recorded. Later, a male and a female monkey were introduced. In order for the pairing to be considered “successful,” the monkeys must show active attention to their proposed partner. Results indicated a reverse effect for the males and females. Females showed high pairing rates when the male monkey that was introduced, was similar to the female. On the other hand, males showed high pairing rates when the female was complementary. This occurs because the male monkeys paired with females that were less dominant than them. The females wanted a partner that was most similar to them behaviorally (p. 1-11). All in all, differences in mate preference can occur through sex. Males can differ in the kind of partner they want from females. Each sex evolutionarily is equipped to search for their most suitable partner, whether similar or complementary.
Even with all the research presented, no concrete answer is available to determine which relationship dyad provides the most satisfaction. An individual may date someone similar to them and then date someone complementary to them, ending them both for different reasons. Dating and relationships are very subjective; the individual picks and chooses who they want. Complementary theorists would state that the individual wants a partner with traits they do not personally have. On the other hand, similarity theorists praise relationships with partners who have the same traits because they relate to each other better. Both complementary and similarity theories are able to provide satisfaction to specific couples. Therefore, the claim that one dyad overrules the other, cannot be made. All in all, the subject of relationship dynamics show promise for future research, however, relationships will always be subjective making it difficult to pinpoint one certain answer.