Birth Order: Are You First Born or an Only Child?

Psychology 101: The 101 Ideas, Concepts and Theories that Have Shaped Our World - Adrian Furnham 2021

Birth Order: Are You First Born or an Only Child?

How parents interact with each child as he or she enters the family circle determines in great part that child’s final destiny. (Kevin Leman, 1982, The Birth Order Book: Why You Are the Way You Are)

Lacking older siblings, the oldest or only child identifies primarily with her parents, conforming to their ideals and demands, not the least reason being that she has no one with whom to share those demands. Since firstborns try to live up to the expectations of adults — teachers as well as parents — rather than that of peers, they are likely to learn more and to bring home better report cards than younger siblings. Thus firstborns pave the way for younger siblings, setting the standards against which they are measured and measure themselves. (Victoria Secunda, 1992, Women and their Fathers)

Are you an only child, or perhaps the first born? What is it like being the youngest of many children? In short, does birth order have an effect on your personality and values? People often attribute certain behaviours and relationships to where someone comes in the family — first, second or perhaps last born. What is the theory and is there any evidence for it?

In 1874, Francis Galton noted that first-born sons and only sons were over-represented among scientists, making birth order one of the first constructs studied in psychology. He thought this was due to both practical circumstances — ’they are more likely to become possessed of independent means, and therefore able to follow the pursuits that have most attraction to their tastes.’ — and their ’independence of character’, a result of having been treated more as companions by their parents. Since then, numerous studies have investigated systematic differences in intelligence, achievement and personality between children of different birth orders. A number of theories have been postulated to account for such differences, generally focusing on the fact that each child’s home environment is at least partly a function of their birth order.

Alfred Adler, a student of Freud, gave what is likely the first comprehensive account of birth order, focusing on the ’dethronement’ concept. The eldest child was, at some point, the centre of attention; this is lost with the addition of a sibling. Younger children, in contrast, see their elder siblings as ’pacesetters’, and race to catch up. The youngest child, in contrast, is never dethroned, and is often pampered and spoiled. A number of effects on personality are predicted on this basis.

There have been many papers and reviews in this area. This is what the data suggest about the characteristics of birth order such as their personality, intelligence, motivation and sexual orientation.

Characteristics of First-Born Children: highest academic/intellectual performance, high achievers, highly motivated, most likely a leader/dominant, most affiliative, over-represented among learned people, most influenced by authority, conformist to parental values, least conventional sexually, most fearful in new situations, earliest sexuality experiences, most likely to be politician, responsible and conscientious, shows mature behaviour, highest self-esteem, dependent on others’ approval, most vulnerable to stress, self-disciplined and least emotionality.

Characteristics of Only Children: most need for achievement, most likely to go to college, most behavioural problems, lowest need for affiliation, selfish, need for affiliation under stress, highest percentage of psychiatric disorders, most likable (exclude youngest), most cooperative and most trusting.

Characteristics of Middle Children: feelings of not belonging, sociable, fewest ’acting out’ problems, success in team sports, relates well to older and younger people, competes in different areas than oldest and more faithful in monogamous relationships.

Characteristics of Youngest Children: highest social interest, general agreeableness, most rebellious, most empathic, most likely to be an alcoholic, over-representation of psychiatric disorder, more artistic, less scientific, most popular and chooses activities involving social interplay.

This area of research has been dominated by Frank Sulloway who, in his book Born to Rebel (1996) presented 26 years of statistical evidence to demonstrate how first-born children behave differently from their younger siblings. His thesis is that children compete for parental attention by creating distinctive niches. First-born children tend to be responsible, competitive and conventional. Children born later are more playful, cooperative and rebellious.

Sulloway provides thousands of birth order examples, historic and contemporary, to prove his point. His research and arguments are impressive.

It is not surprising, therefore, to find many followers of his theory. Among them, Leman (1998) states that the first male or those born more than five years after their older sibling have an excellent chance of developing first-born traits or being ’functional first borns’. Sulloway and Leman provide an extensive list of famous people who fit into the categories they identify.

Intriguing and fascinating as these studies are, subsequent analyses challenge Sulloway’s main theories. Some researchers reported studies that found no significant correlations between personality and birth order. Peer ratings suggested partial support for Sulloway’s hypotheses. According to Jefferson et al. (1998) later-borns are perceived by ’their friends and neighbours as being more sociable, innovative and trusting than first-borns’. Interestingly, the spouses of the individuals concerned did not replicate these peer-rated results.

The debate continues. There are some tempting conclusions to be drawn from the analysis of the impact of birth order on personality and behaviour, but the precise impact is not yet sufficiently defined. One problem is that birth order is related to other factors like social class: poorer families have more children. It is still probably true that most scientists are deeply sceptical, believing that many of the claims of the birth-order theorists are simply wrong.


Eckstein, D., Aycock, K. J., Sperber, M. A., McDonald, J., Van Wiesner, V., Watts, R. E., & Ginsburg, P. (2010). A review of 200 birth-order studies: Lifestyle characteristics. Journal of Individual Psychology, 66, 408—34.

Eckstein, D., & Kaufman, J. A. (2012). The role of birth order in personality: An enduring intellectual legacy of Alfred Adler. Journal of Individual Psychology, 68(1).

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