1. Like A Boss. Think about the romantic relationships in your life - and your friends' lives - that worked (at least temporarily) and the ones that quickly fizzled. What were the birth orders of those involved? Do you see any patterns? For example, if you're a first-born, do you tend to get along more easily with latter-borns, but clash with fellow first-borns? If you're a younger or middle child, is the opposite true? Although birds of a feather tend to stick together when it comes to most characteristics, there is some evidence that opposites do attract when it comes to complementarity between dominance and submission (e.g. Dryer & Horowitz, 1997). That is, a partnership of alphas may run into problems. To the extent that first-borns are used to being "the boss," they might be more compatible with partners who are used to playing the more submissive role (i.e., latter-borns). This is not to say that first-borns are power-hungry dictators, but they might be more likely to, say, take the lead in planning a travel itinerary, while their latter-born partner may be happy to just go with the flow. Consistent with this idea, Sulloway (2001) cites evidence that first-borns tend to be more dominant with their spouses (though this is not the case in their interactions with peers).
2. Stuck In The Middle. Being a middle child seems to be a double-edged sword. On the one hand, research suggests that middle children tend towards insecure attachment and jealousy, perhaps because of early experiences of feeling they have to fight tooth and nail for their parents' attention. On the other hand, they may also be able to handle conflict better (the "peace-maker" niche) and be flexible enough to get along well romantically with either first or latter borns.
3. One Is Not The Loneliest Number. Early research suggested that "singletons" were at a disadvantage, but that idea has now been discredited. More recent research suggests that only children do just as well (if not better) academically, in part because their parents may have more time and financial resources available to support them. Only children may also have the advantage of greater maturity and self-esteem. It's unclear what this means for compatibility, though - only's may appreciate the extended family they gain through a partner with siblings, or they may feel a kinship with those who had a similar childhood experience.
4. Save The Best For Last. Having an older sibling, especially if this sibling is of the opposite sex, seems to be a major asset when it comes to charming opposite sex strangers. In one study, researchers found that male participants with older sisters, compared to firstborn men with younger sisters, were more talkative, asked more questions, and were better liked by female interaction partners. Female participants with older brothers were also better liked, and elicited more smiles. This research fits in with other findings suggesting that latter-borns are generally more socially skilled, regardless of their siblings' gender, and may have more success romantically.
As fascinating as this research is, it's also controversial (some have found no personality differences based on birth order), and, importantly, it is intended to describe general patterns, not encompass all individual experiences (there are plenty of dominant, driven younger children). There are also many additional factors that come into play with sibling dynamics - gender, age differences, emotional closeness, and characteristics of the family environment. So there's no need to let birth order dictate your romantic decisions, but if you're like me it might be a fun way to try to understand why some relationships may have worked better than others.
Do you feel like your birth order has played a role in your romantic relationships? If so, let us know how in the comments section!
Jefferson, T., Herbst, J., & McCrae, R. (1998). Associations between Birth Order and Personality Traits: Evidence from Self-Reports and Observer Ratings Journal of Research in Personality, 32 (4), 498-509 DOI: 10.1006/jrpe.1998.2233
Sulloway, Frank J. (1996). Born To Rebel: Birth Order, Family Dynamics, and Revolutionary Genius