How Birth Order and Sibling Relationships Shape Our Personality

Typical Traits Related to Birth Order

Approximately 80% of children in the United States grow up with at least one sibling[1], which makes us consider: how does having a sibling affect a child’s social development and personality? 

Comprehensive MedPsych Systems (2023) built a very thorough description and explanation for the traits that are often associated with each birth order. While these will not be applicable to everyone and all families, they are commonalities found among a family’s oldest child, middle children, youngest child and children without siblings based on parenting style and familial structure.

For example, a family’s oldest child (i.e., firstborns) are often responsible, independent, perfectionistic, rule-followers, role models, and hard workers. These traits are often developed from the attention that firstborns receive due to being the only child, as well as the care that first-time parents generally have with their oldest children. Parenting can be extremely scary and difficult; therefore, first-time parents are typically stricter.  Further, because this is their only child, they are able to devote all of their attention to this child. As siblings are introduced into the family, older children tend to develop leadership skills and responsibility as they are deemed as role models, often helping with household tasks (e.g., babysitting, chores).[2]

Middle children are often diplomatic, adaptable, funny, creative, sociable, rebellious, and competitive. These children are often trying to compete for attention with their other siblings and tend to be typically very flexible and more comfortable “going with the flow”. Middle children also have the unique experience of being the youngest child for some time before another sibling is born, but then can experience a shift toward the character of an older sibling, especially if there is a large age gap between them and the first-born.[3,4]

Youngest children are often outgoing, dependent, easy-going, mischievous, and free-spirited. They are typically deemed “the baby of the family” because they are not only the youngest, but also receive more attention from their parents as their siblings get older. Additionally, they tend to receive a more lenient and laid-back parenting style as third-time parents become more comfortable parenting. Dr. Catherine Salmon, a professor of psychology at the University of Redlands and co-author of The Secret Power of Middle Children, explains that “In general, high agreeableness, extraversion (the social dimension) and openness are associated with youngest children, and sometimes low conscientiousness due to lack of responsibilities and parental indulgence over expectations.”[5]

An only child shares many traits with first borns such as independence and leadership, but they are also known to be mature, loyal, sensitive, and confident. They are typically raised with their parent’s full attention, and as an only child, may be raised with higher expectations and pressure.[6] Krynen (2011) notes that the intelligence and motivation achievement scores are significantly higher, and they typically complete more years of education as well as obtain more prestige than those with siblings. Only children are also known to be very creative and imaginative, as they often spend more time alone and therefore, are more likely to invent imaginary friends or scenarios.[7] 

The Effect of Siblings on a Child’s Social Development

Sibling relationships are often vastly underestimated in their importance. While research often evaluates the effects of parental behavior on children’s development, their sibling relationships are often overlooked. However, Dr. Shawn Sidhu from the University of New Mexico, explains that siblings are often consistent sources for support and aid in the development of positive emotional competence because we share more information and confide in our siblings more often than we do our parents, specifically regarding topics such as friendships, relationships, and school.[8] 

Siblings also appear to one another as consistent sources for support and help children learn how to manage conflict and various socio-emotional skills at a young age, while many children without siblings don’t learn these behaviors until preschool or kindergarten. McHale et al. (2012) explains, “Through their conflicts, for example, siblings can develop skills in perspective taking, emotion understanding, negotiation, persuasion, and problem solving. Notably, these competencies extend beyond the sibling relationship and are linked to later social competence, emotion understanding, and peer relationships. In adolescence, siblings also contribute to positive developmental outcomes, including prosocial behavior, empathy, and academic engagement.”[9] McHale also confirms that those with close sibling relationships often have better mental health, better psychological health, and better social relationships.[10] Furthermore, even if siblings struggle to get along as kids, psychologist Jill Suttie (2022) explains that sibling relationships do change throughout their lifetime and often siblings become closer as they reach and extend into adulthood.[11]

While there are many positive effects that siblings can have on a child’s development, there are also some negative effects that can occur depending on the circumstances. Because a child is often surrounded by their siblings more than almost anyone else, an unhealthy or toxic sibling relationship can have detrimental effects on a child’s social development. Since siblings are often seen as support systems and are consistent in a child’s life, bullying from a sibling can be more devastating than peer bullying, as their home is no longer an escape.[12] 

Furthermore, psychiatrist Shawn Sidhu explains that children are often compared to their siblings in academic or athletic settings by coaches, teachers, and peers, which can lead to children internalizing their incompetence in comparison. This causes lower self-esteem, and can drive a wedge in their sibling relationship.[13]

Lastly, since older siblings are often role models for their younger siblings, negative or unhealthy behavior by the older siblings can introduce and encourage bad behavior for younger siblings.[14] Suttie (2022) explains, “Research confirms that if siblings have hostile or conflicted relationships when young, it can increase their risks of suffering anxiety, depressive symptoms, and even risky or antisocial behavior later in adolescence.”[15]

While several debates remain regarding which situation is better for a child’s development, having siblings or being an only child both have their unique sets of pros and cons. Additionally, while research has found that a person’s birth order tends to predict specific traits in each child due to both different parenting techniques and sibling competition, these traits are also affected by a slew of environmental factors such as the child’s age, sibling age gap, and family income.[16]

If you or someone you know would like to learn more about or are struggling with their family dynamic, please reach out to a licensed mental health professional (e.g., a psychotherapist, psychologist or psychiatrist) for additional guidance and support.

Contributed by: Kendall Hewitt

Editor: Jennifer (Ghahari) Smith, Ph.D.

References

1 Weir, K. (2022). Improving Sibling Relationships. American Psychological Association, 53(2). 

https://www.apa.org/monitor/2022/03/feature-sibling-relationships#:~:text=Sibling%20warmth%20and%20support%20in,review%20of%20sibling%20dynamics%20in

2 What Your Sibling Birth Order Reveals About Your Personality Traits (Even If You’re an Only Child). (2023). Comprehensive MedPsych Systems. https://www.medpsych.net/2021/08/19/what-your-sibling-birth-order-reveals-about-your-personality-traits-even-if-youre-an-only-child/

3 Ibid.

4 Shanley, S. (2015). What Happens When The Youngest Child Becomes the Middle Child. The Washington Post. https://www.washingtonpost.com/news/parenting/wp/2015/03/23/what-happens-when-the-youngest-child-becomes-the-middle-child/ 

5 Comprehensive MedPsych Systems (2023)

6 Ibid.

7 Krynen, C. (2011). The Rise of Single-Child Families: Psychologically Harming the Child?  Intuition: The BYU Undergraduate Journal of Psychology, 7(1)(3). https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=1191&context=intuition

8 Sidhu, S. (2019). The Importance of Siblings. The University of New Mexico Health Sciences Newsroom. https://hsc.unm.edu/news/news/the-importance-of-siblings.html

9 McHale, SM., Updegraff, KA., & Whiteman, SD. (2012). Sibling Relationships and Influences in Childhood and Adolescence. J Marriage Fam, 74(5), 913-930. doi:10.1111/j.1741-3737.2012.01011.x

10 Suttie, J. (2022). How Your Siblings Can Make You Happier. The Greater Good Science Center at the University of California, Berkeley. https://greatergood.berkeley.edu/article/item/how_your_siblings_can_make_you_happier 

11 Ibid.

12 Sidhu (2019)

13 Ibid.

14 Ibid. 

15 Suttie (2022)

16 Comprehensive MedPsych Systems (2023)

The Big Five Personality Traits: Exploring the Connection Between Personality & Mental Health

Origins: The Formation of the Big Five

Some people are more outgoing than others; some prefer to keep to themselves. Some people love to argue and others prefer to keep the peace. Some people are highly organized, making their beds every morning; others can hardly find a pair of socks under the mountain of a pile of clothes. In our own experience of life, we can probably think of a vast variety of individuals with their own personalities, each coping uniquely with the challenges life throws at them.

Personality psychologists have come up with a concept of ‘traits’ – the stable tendencies of individuals – to explain everyday behaviors like journaling, throwing socks on the floor, cleaning after themselves, etc. But how do we figure out which traits are the most important? Are there any traits that serve as the most common among every individual? Can we describe someone’s personality in just a few words? To answer these questions, personality psychologists have tried for more than a century to develop a comprehensive measure of personality traits, resulting in questionnaires such as the Minnesota Multiphasic Personality Inventory (MMPI).

The modern study of personality psychology is attributed to Francis Galton who developed the idea of the lexical approach.[1] This idea explains how language captures the traits most important to people in their everyday lives. It argues that if a trait is important, then it would be encoded in language with individual words such as “nervous” or “outgoing”. Following this reasoning, all of the adjectives in the English dictionary were recorded; screening out words that referred to momentary states (e.g., annoying), the remaining words alluded to psychological attributes (e.g., outgoing, nervous, and neat).[2]

After the researchers had people rate themselves on the recorded adjectives, they did a factor analysis [3,4] which formed groups of adjectives based on their correlation with each other. This resulted in five major factors that had the most adjectives, which we now know as the Big Five Personality Traits: Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience. 

Understanding the Big five Personality Traits

These five factors are best understood as a continuum of traits, each having its own sub-categories (i.e., facets).[5] The following facet examples helps explain the diversity of characteristics within each grouping:[6]

1. Extraversion: friendliness, gregariousness, assertiveness, activity level, excitement seeking, cheerfulness

2. Agreeableness: trust, morality, altruism, cooperation, modesty, sympathy

3. Conscientiousness: self-efficacy, orderliness, dutifulness, achievement-striving, self-discipline, cautiousness

4. Neuroticism: anxiety, anger, depression, self-consciousness, immoderation, vulnerability

5. Openness to Experience: imagination, artistic interests, emotionality, adventurousness, intellect, liberalism

Internalizing these facets also helps us avoid common misunderstandings about the traits. Apart from being a continuum, there is no “right” or “wrong” personality – each trait has its advantages and disadvantages. For example, the extrovert might delve too much into excitement-seeking which can turn out to be reckless at times. The neurotic person, on the other hand, might be anxious, but that will prevent them from reckless behavior.

The Five traits and Mental Health

1. Extraversion

Extraversion is the dimension that ranges from how outgoing and stimulant-seeking a person is to how much they conserve their energy and do not actively engage to earn social rewards. Extraversion includes preferring the company of others as opposed to being alone, aspiring for leadership roles, being physically active, and experiencing more happiness and joy. It captures the most positive emotions – joy, energy, happiness – out of all the traits because of which extraverts are more likely to experience positive moods.[7] Due to its link with positive emotions, individuals who score higher on extraversion tend to have better mental health; they are less likely to suffer from mood and anxiety disorders.[8] These benefits occur not from extraversion itself but because extroverts are often better at maintaining relationships, which are linked to physical and mental health.[9]

The opposite dimension of extraversion is introversion. Introverts are not hermits who isolate themselves; instead, they prefer the company of close friends and family as opposed to large gatherings. Hans Eysenck (1967) posited that introverts are sensitive to stimuli which causes them to prefer solitude.[10] On the other hand, extroverts seek stimulation and excitement which might be linked to higher levels of dopamine – the brain-chemical responsible for pleasure.[11]

2. Agreeableness

The dimension of agreeableness describes an individual’s tendency to put others’ needs ahead of their own, making those low in agreeableness more antagonistic. Agreeable individuals are sympathetic to the needs and feelings of others and trust them more. They prefer cooperation as opposed to competition and tend to be honest, humble, and compliant. In short, individuals high in agreeableness tend to hold other people’s needs above their own; they tend to gain pleasure from serving others and taking care of them.[12] While agreeableness is the least studied factor in the Big Five, most research on it is done by investigating both ends of its spectrum.[13] The opposite end of the agreeableness spectrum – antagonism – encompasses characteristics such as: angry, argumentative, hostile, egotistical, condescending and skeptical.[14]

Unfortunately, these characteristics result in a correlation with antisocial behavior. Research has found that disagreeable individuals are more likely to be involved in crime, aggressive behavior, drug abuse, and gambling.[15-18] Those high in agreeableness, however, show behavior that includes helpfulness, forgiveness, and acceptance.[19] As a result of prosocial behavior, agreeableness comes with many benefits which include, but are not limited to: positive emotions, decreased depression, healthy social connections and relationships as well as greater life satisfaction.[20]

3. Conscientiousness

This dimensional trait measures an individual’s self-discipline and control in order to achieve their goals, making those on the other end of the spectrum more impulsive. Conscientiousness involves willpower; individuals high in this trait can delay gratification, consider the consequences before acting, and work hard toward their goals. As a result, conscientious people are diligent and organized, achieving their goals despite boredom, frustration, or distractions. Similar to individuals low in agreeableness, research has found those low in conscientiousness are more likely to abuse drugs, involve themselves in criminal behavior, and gamble more often.[21]

Due to greater self-control, highly conscientious people tend to enjoy better mental and physical health, including living longer.[22,23] Willpower motivates this cohort to be more-likely to exercise, follow a well-balanced diet, avoid drug abuse, and achieve educational and career goals to try and avoid stressful financial problems. For example, they have been found more likely to eat salads and are less likely to be overweight.[24] They also benefit from better mental health by managing their negative emotions; as a result, perhaps, conscientious people are more likely to have stable marriages.[25]

4. Neuroticism

This spectrum describes how much someone experiences negative emotions as a reaction to a situation. Neuroticism is the tendency to experience negative emotions such as anger, depression, anxiety, shame, and self-consciousness. Highly neurotic individuals may experience negative emotions more frequently and intensely. As a result, they are more prone to mental health issues such as depression, generalized anxiety disorder, PTSD, OCD, substance abuse disorder, and eating disorders.[26-28]

An individual high in neuroticism is less likely to engage in processing their emotions than an individual who does not worry often. To aid a neurotic person in psychotherapy, it is beneficial to help them overcome their inclination to avoid emotions. This is better achieved by helping them realize their emotions as negative, instead of figuring out the origin of their emotions. It is this suppression that harms their mental health, so labeling their emotions as negative serves to alleviate the stress they experience.[29]

5. Openness to Experience

The openness dimension ranges from thinking in abstract, complex ways to thinking more traditionally. Openness is the least intuitive of the Big Five. It has been labeled differently – such as ‘intellect’, ‘culture’, and ‘imagination’ – in many personality questionnaires; McCrae (1996) defined it according to the lines of ‘vivid fantasy’, ‘intellectual curiosity’, ‘behavioral flexibility’, and ‘unconventional attitudes’.[30] Individuals high in openness to experience love to try new things, play with complex ideas, and consider alternative perspectives. Most importantly, they are more likely to name travel as an important personal goal.[31] For example, they are more likely to engage in meditation (associated with new experiences), go to art exhibits, or speak a foreign language.[32] In contrast, low-openness people value the status quo, favor traditional activities, and prefer routine.

Openness does not have many links with psychiatric disorders; however, researchers argue having too much vivid imagination overlaps with psychotic symptoms like hallucinations or unusual beliefs.[33] Overall, those high in openness are less likely to suffer from anxiety disorder or depression.[34] It is also the only factor linked with intelligence; although the correlation is small, those high in openness tend to score higher in IQ tests.[35] The facets of being highly open to experience allow an individual’s brain to retain its plasticity as they age, minimizing the decline in cognitive abilities.

Again, it is important to note how the five personality traits are a continuum more so than a concrete representation of who we are. Since life is not black and white but nuanced in essence, how we react to situations is equally gray and can differ from situation to situation. Just as our personality traits can determine how we react to circumstances; our circumstances can also impact our personality traits. Nevertheless, it is beneficial and empowering to know our personality features as it can equip us with a better understanding of ourselves and the people around us. It can help us cater to the specific characteristics of our friends and colleagues and at the same time allow us to make better choices considering our personalities.

Contributed by: Musa Zafar

Editor: Jennifer (Ghahari) Smith, Ph.D.

REFERENCES

1 De Vries, R. E., Tybur, J. M., Pollet, T. V., & Van Vugt, M. (2016). Evolution, situational affordances, and the HEXACO model of personality. Evolution and human behavior, 37(5), 407-421.

2 Cattell, R. B. (1943). The description of personality: Basic traits resolved into clusters. The journal of abnormal and social psychology, 38(4), 476.

3 Norman, W. T. (1963). Toward an adequate taxonomy of personality attributes: Replicated factor structure in peer nomination personality ratings. The journal of abnormal and social psychology, 66(6), 574.

4 Goldberg, L. R. (1993). The structure of phenotypic personality traits. American psychologist, 48(1), 26.

5 Bratko, D., & Marušić, I. (1997). Family study of the big five personality dimensions. Personality and Individual Differences, 23(3), 365-369.

6 Ibid.

7 Lucas, R. E., Le, K., & Dyrenforth, P. S. (2008). Explaining the extraversion/positive affect relation: Sociability cannot account for extraverts' greater happiness. Journal of personality, 76(3), 385-414.

8 Kotov, R., Gamez, W., Schmidt, F., & Watson, D. (2010). Linking “big” personality traits to anxiety, depressive, and substance use disorders: a meta-analysis. Psychological bulletin, 136(5), 768.

9 Pollet, T. V., Roberts, S. G., & Dunbar, R. I. (2011). Extraverts have larger social network layers: But do not feel emotionally closer to individuals at any layer. Journal of Individual Differences, 32(3), 161.

10 Eysenck, S. B., & Eysenck, H. J. (1967). Salivary response to lemon juice as a measure of introversion. Perceptual and motor skills, 24(3_suppl), 1047-1053.

11 Wacker, J., Chavanon, M. L., & Stemmler, G. (2006). Investigating the dopaminergic basis of extraversion in humans: A multilevel approach. Journal of personality and social psychology, 91(1), 171.

12 Psychology Today. (n.d.). Agreeableness. Retrieved from https://www.psychologytoday.com/us/basics/agreeableness

13 Miller, J. W., & Lynam, D. (Eds.). (2019). The handbook of antagonism: Conceptualizations, assessment, consequences, and treatment of the low end of agreeableness. Academic Press.

14 Graziano, W. G., & Tobin, R. M. (2017). Agreeableness and the five factor model. The Oxford handbook of the five factor model, 1, 105-131.

15 Miller, J. D., & Lynam, D. (2001). Structural models of personality and their relation to antisocial behavior: A meta‐analytic review. Criminology, 39(4), 765-798.

16 Jones, S. E., Miller, J. D., & Lynam, D. R. (2011). Personality, antisocial behavior, and aggression: A meta-analytic review. Journal of Criminal Justice, 39(4), 329-337.

17 Lackner, N., Unterrainer, H. F., & Neubauer, A. C. (2013). Differences in Big Five personality traits between alcohol and polydrug abusers: Implications for treatment in the therapeutic community. International Journal of Mental Health and Addiction, 11(6), 682-692.

18 MacLaren, V. V., Fugelsang, J. A., Harrigan, K. A., & Dixon, M. J. (2011). The personality of pathological gamblers: A meta-analysis. Clinical psychology review, 31(6), 1057-1067.

19 Psychology Today

20 Aknin, L. B., & Whillans, A. V. (2021). Helping and happiness: A review and guide for public policy. Social Issues and Policy

21 Miller, J. D., & Lynam, D. (2001). Structural models of personality and their relation to antisocial behavior: A meta‐analytic review. Criminology, 39(4), 765-798.

22 Kotov, R., Gamez, W., Schmidt, F., & Watson, D. (2010)

23 Kern, M. L., & Friedman, H. S. (2008). Do conscientious individuals live longer? A quantitative review. Health psychology, 27(5), 505.

24 Keller, C., & Siegrist, M. (2015). Does personality influence eating styles and food choices? Direct and indirect effects. Appetite, 84, 128-138.

25 Claxton, A., O’Rourke, N., Smith, J. Z., & DeLongis, A. (2012). Personality traits and marital satisfaction within enduring relationships: An intra-couple discrepancy approach. Journal of Social and Personal Relationships, 29(3), 375-396.

26 Lahey, B. B. (2009). Public health significance of neuroticism. American Psychologist, 64(4), 241.

27 Kotov, R., Gamez, W., Schmidt, F., & Watson, D. (2010) 

28 Samuel, D. B., & Widiger, T. A. (2008). A meta-analytic review of the relationships between the five-factor model and DSM-IV-TR personality disorders: A facet level analysis. Clinical psychology review, 28(8), 1326-1342.

29 Whitbourne, S. K. (2020, January 18). Neuroticism, emotions, and your health. Psychology Today. Retrieved December 6, 2022, from https://www.psychologytoday.com/us/blog/fulfillment-any-age/202001/neuroticism-emotions-and-your-health 

30 McCrae, R. R. (1996). Social consequences of experiential openness. Psychological bulletin, 120(3), 323.

31 Reisz, Z., Boudreaux, M. J., & Ozer, D. J. (2013). Personality traits and the prediction of personal goals. Personality and Individual Differences, 55(6), 699-704.

32 Chapman, B. P., & Goldberg, L. R. (2017). Act-frequency signatures of the Big Five. Personality and Individual Differences, 116, 201-205.

33 Widiger, T. A. (2011). The DSM-5 dimensional model of personality disorder: Rationale and empirical support. Journal of Personality Disorders, 25(2), 222.

34 Kotov, R., Gamez, W., Schmidt, F., & Watson, D. (2010) 

35 DeYoung, C. G., Quilty, L. C., Peterson, J. B., & Gray, J. R. (2014). Openness to experience, intellect, and cognitive ability. Journal of personality assessment, 96(1), 46-52.