How often do you hear, “Oh, they’re both oldest children? Oh yeah… that’ll last.” Or, “She’s the baby of the family? She must be spoiled…” Ok, maybe you don’t hear it as much as much as I do; however, chances are you have heard something about the relationship between birth order and personality traits. The question is… “is it true?”

Why do people feel that birth order differences exist?

I really feel that Ziv & Hermel (2011) stated the most concisely why people feel this difference between birth order and personality exist. They explain in a recent journal article that parental care is not evenly divided between all siblings. It is not that parents intentionally give more attention to one child than the other; it is just what ends up happening. When the first child is born, the child is often showered with attention and resources, and they do not have sibling to share the resources with. They are new to the family, they are exciting their parents. They’re the first one! When the second child comes, the parents are then having to split all their resources between two children now instead of one. If the parents have no more children, the balance can be restored once the oldest child leaves the home. The second child then becomes, essentially, an “only child” because there is no one else at home to split their attention with. A lot of this is affected by the age difference between the two children. However, if the parents have a third child, the middle child never gets their alone time with the parents. The “baby” becomes an only child again when everyone else leaves the home. Ziv & Hermel go on to explain…

The competition between siblings for parental investment leads children to adopt family niches that are associated with birth order … As a result, middleborns  prefer nonfamilial social interactions to familial ones, and they develop advanced social skills relative to firstborns and lastborns.

What some of the research says…

Research has reported some distinct differences between first and last born children. MacDonald (1971) and Sulloway (1996) are two of the most cited researchers in this field. Sulloway is often noted for his findings that the youngest children are often seen as rebels who want to change the world, while the oldest children are conscientious and support sticking with the “status quo”. MacDonald is known for his findings that state the younger born children are more likely to have an external-locus of control (they are more likely to believe that forces outside their control lead their behaviour), while the older children are more likely to have internal-locus of control (more like to believe that they themselves, and not the external environment, control their behaviour). He also stated that the older children are more “socially responsible” and rigid compared their younger siblings.

In regards to locus of control, Carette, Anseel & Van Yperen (2011) did find that first-born children are more likely to measure their success against themselves. In addition, they often strive to meet goals in this same way, striving for an increase in knowledge, skill sets, and mastering tasks. Second-born children, however, are more likely to measure their successes against other people. They will strive prove how they are more competent than others… in essence, they want to be the “winners”.

Ziv & Hermel (2011) who I mentioned earlier, also found in their study that because the middle-born children are more likely to receive less parental attention and resources and have the highest level of separation from their family units as young adults. Their older and counterparts have the second highest level of separation, while the youngest tends to have the least of the three.

Another study found that our personality traits tend to affect the type of parenting style we have. However, they also found that whether you are the oldest, middle, or baby in your family can play a role in the parenting you receive. Parents tend to use a authoritarian parenting style on middle and only children. Only children also tend to feel more pressure from their parents, as if they are their parents “only chance for success. Children of authoritarian parenting styles are also more likely to feel that their life as unfair and strict. Lastly, Parents who feel that they have a sense of belonging and social interest are more likely to use an authoritative parenting style on their children than other parent’s personality traits (Gfroerer, Kern, Curlette, White & Jonyniené, 2011). And can you guess what sets of siblings see the highest rates of birth order differences? Well, according to Healey & Ellis (2007), it is sets of girls.

What the other Research says…

The problem with this topic, is that the research varies. Some research findings find results as stated above, while others find no statistical significance (Marini & Kurtz, 2011; Harthshorne, 2011). The problem is, in many of the research articles, it is hard to completely account for cultural, socio-economic, and parenting style differences. In addition, not all the studies measure personality in the same way. Some people swear by the research that there are personality differences based on birth order. Others swear that it’s a hyped up myth. It is sure clear that more concise research is needed to confidently rule in either direction.

In Sum…

While we may not be able to fully understand the effects of birth order, we do know one thing for sure. Each member of the family experiences family life and events differently from everyone else. Depending on the age of the child, they may not have the knowledge and capacity to fully understand certain situations. They may be the oldest and have more of understand of what’s happening in the family than the younger children. No matter what way you look at it, the view-point is skewed in some direction. It’s not good or bad, it’s just important to understand and know. If nothing else, the birth order is still a fun debate to have with another friend and read about.

What are your views of birth order? Do you think the placement in your family affected the way your personality turned out? Do you feel you were treated differently from your siblings?

Works Cited

Carette, B., Anseel, F., & Van Yperen, N. (2011). Born to learn or born to win? birth order effects on on achievement goals. Journal of Research in Personality45, 500-503.

Gfroerer, K., Kern, R., Curlette, W., White, J., & Jonyniené, J. (2011). Parenting style and personality: Perceptions of mothers, fathers, and adolescents. Journal of Individual Psychology,67(1), 57-73.

Hartshorne, J. K. (2011, January 11). How birth order affects your personality. Scientific American Mind, Retrieved from

Healey, M. D., & Ellis, B. J. (2007). Birth order, conscientiousness, and openness to experience tests of the family-niche model of personality using a within-family methodology. Evolution and Human Behavior28, 55-59.

MacDonald, A. (1971). Birth order and personality. Journal of Consulting and Clinical Psychology36(2), 171-176.

Marini, V. A., & Kurtz, J. E. (2011). Birth order differences in normal personality traits: Perspectives from within and outside the family. Personality and Individual Differences51, 910-914.

Sulloway, F. J. (1996). Born to rebel: Birth order, family dynamics, and creative lives. New York, NY: Pantheon Books.

Ziv, I., & Hermel, O. (2011). Birth order effects on the separation process in young adults: An evolutionary and dynamic approach. The American Journal of Psychology124(3), 261-273.

Birth Order and Personality: Is there a really a difference?
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