The Effects of Birth Order on Psychosocial Development and its Link to Sibling Rivalry

Ingy ElAdly
· 10 min read

Through myths and societal aspects, people have started to develop preconceived notions in regards to a child’s birth order or position within a family. Examples vary starting from perceiving the eldest child as the most responsible to viewing the youngest as being the most spoiled. To what extent are these notions facts and to what extent do they remain myths that we hold on to in order to easily categorize people into boxes that aid in dealing with them better?
In this article, an analysis of a family of three siblings will be thoroughly examined in order to effectively understand how a child’s birth order or family position can have an affect on his/her psychosocial development and the overall family structure and dynamics.

According to the Adlerian Theory, Alfred Adler stated that each sibling had certain characteristics attributed to his/her personality solely based on his/her birth order. These characteristics are as a result of a lot of research done on siblings and family dynamics (Cullen, 2011). To understand sibling rivalry and the relationship between siblings, excerpts of Freud’s work will be analyzed. Let’s take a look at how both viewed the family structure of a family of three siblings.

The oldest child is viewed as the “only” one (in the beginning) which stresses the parental energy and attention this child demands. When the eldest loses that position to the birth of a new baby, this burden of a younger sibling forces the first child to become responsible. Sometimes that brings feelings of sadness and resentment to the surface as it highlights the experience of loss and deprivation of the maternal object (Rohrer, Egloff & Schmukle, 2015). Hence, sibling jealousy, rivalry, envy and sometimes even death wish could be stirred against this new arrival. An arrival that creates fear that the child may cease to be cared for and loved (Freud, 1950d). This creates a threat (of annihilation) to the child as he/she believes that there’s someone else trying to claim their place within the family dynamics. To maintain that place, they sometimes take over their parents’ role in taking care of the younger sibling, so the parents devote more time for him/her and shower them with love and attention.

On a positive note, this affective potency of emotions during early childhood can stimulate emotional and intellectual development; the arrival of a new baby, makes a child ask questions that range from, “Where and how do babies come from?” to sexual differences and their meanings. A statistic revealed by Adler states that in the worst case, the eldest child is the one most likely to suffer from mental health problems and/or criminal behavior (Cullen, 2011). This statistic is backed up by and explains Freud’s quote, “Children are completely egoistic; they feel their needs intensely and strive ruthlessly to satisfy them - especially against rivals, other children and first and foremost as against brothers and sisters” (as cited in Hindle & Sherwin-White, 2014, p.15).

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The middle child suffers from feelings of not belonging and thus having to rebel in order to establish a strong position within the family dynamics. Statistics show that they’re the most likely to be successful in life which is due the fact that they are the ones that try their hardest to fit in and prove their worth and position (Cullen, 2011).

The youngest child is lavished with love, material benefits and attention. This makes him/her have an over-inflated sense of self and selfishness which in hindsight highlights his/her lack of awareness and social empathy. Statistics show that those children are the ones most likely to under-perform and not fulfill their personal potential (Cullen, 2011).

Early family experiences and parenting patterns play an integral role in how healthy or unhealthy their children will become in their future romantic relationships and how they will function in such dynamics (Rauer & Volling, 2007). When parents give equal affection to their children, children will experience equal jealousy between themselves and their siblings. However, they will also have higher self-esteem, showcase more secure attachment styles and encounter less distress in their future romantic relationships. If one sibling has always been favored or received different parental affection, they are more likely to display negative models of themselves and others and thus, experience more relationship distress.

Freud saw the position of a child in the family structure of great importance in regards to how it determines and shapes the child’s later life. However the key to creating healthy children is understanding that each child needs a mother and a father without having to add a fourth person to the triad. A sibling (the fourth person) is not someone you depend on for your material and psychic survival, hence why the sequence becomes open (in contrast to the triad). In other words, children don’t see siblings as necessary as without them, the child still exists. From here also comes the elemental fear that a child might feel that their existence does not matter (Hindle & Sherwin-White, 2014). There is also the narcissistic threat that the parents have needs and wishes that don’t involve the child, such as care, attention and love devoted to another child and the sexual relationship between the parents. These are all points that parents need to pay attention to in order to bring up children that have values of love and heighted self-worth.

In conclusion, birth order has an effect on a child’s psychosocial development, however its impact on who we become remains scarce. Understanding the characteristics that overlap between categories of age ranges (oldest/middle/youngest) can help parents take more care of their children and better grasp why they behave the way they do. As Freud put it, “Hostile feelings towards brothers and sisters must be far more frequent than the unseeing eye of the adult can perceive” (as cited in Hindle & Sherwin-White, 2014, p.16). During early childhood, there is an intensity of emotions (positive and negative) that are not always brought to the surface. The role of parents is to be able to get those emotions out, embrace them and help children grow to be healthy, safe and sound.


Cullen, K. (2011). Introducing Child Psychology: A Practical Guide. Icon Books Ltd.

Freud, S. (1950d). Three Essays on the Theory of Sexuality. Standard Edition, 7, pp.123-231.

Hindle, D., & Sherwin-White, S. (Eds.). (2014). Sibling matters : A psychoanalytic, developmental, and systemic approach. Taylor & Francis Group.

Rauer, A., & Volling, B. (2007). Differential parenting and sibling jealousy: Developmental correlates of young adults' romantic relationships. Personal Relationships, 14(4), 495–511.

Rohrer, J., Egloff, B., & Schmukle, S. (2015). Examining the effects of birth order on personality. Proceedings of the National Academy of Sciences of the United States of America, 112(46), 14224–14229.