William Antonio Boyle, PhD

April 1999.

[En español]

This short essay discusses the causes, consequences, and solutions to the many social, psychological, and family problems brought about by sibling rivalry, and a mechanism for the origin of the abusive personality.








-Note: Abuse of power


-Readers' Letters

-Additional Reading: Books and Links on Parenting and on Sibling Rivalry

* * *

"A beginning is the time for taking the most delicate care..." - Frank Herbert, Dune, 1965


Sibling rivalry is one of humanity's oldest problems. One of the first stories in the Bible (the oldest book in Western civilization, and the story of the ancient Jewish culture) deals with the rivalry between two brothers, Cain and Abel. The older brother, Cain, was irritated at constantly having to help take care of his younger brother, Abel, and kept asking his parents: "Am I my brother's keeper?" The story of these two brothers has a tragic ending; Cain becomes so angry that he kills Abel (and this, according to the Bible, was the first murder in history). The fact that this is one of the first stories within the Bible shows the great importance given to the problem of sibling rivalry within the Jewish culture (See note 1).


Nowadays, most parents don't seem very concerned with the possible occurrence of this problem within their families. In Western cultures this may in part be due to the prevalence of Christian traditions and education, in which "brotherly love" is assumed to be the "ideal" type of love. Closely related to this problem are some of the most fundamental and difficult questions in two of the modern world's greatest religions, Judaism ("Am I my brother's keeper?,"  which is to say, "Do I have a moral obligation to attend to the well-being of my brothers and sisters?") and Christianity ("Who is my neighbor?,"  which means, "Who are those that I should consider as my brothers and sisters?").  [And readers, please let me know what other religions or belief systems say about these two questions;  Do they include everyone?  Or do they exclude some groups of people, e.g., nonbelievers?  You can leave your answer in my Guestbook.]

In the Christian Gospels, Jesus and his Apostles repeatedly tell their followers to "love one another as brothers." This repeated admonition may tend to give a certain impression that "brotherly love" is a natural condition that will come forth "by itself" whenever there are brothers or sisters within a family, and that parents don't have to do anything but relax and watch the unfolding of this wonderful "natural" phenomenon.

This belief (in brotherly love as a natural condition) appears to overlook the fact that Jesus and his Apostles were born into and raised within the Jewish culture, which at that time was already more than three thousand years old. Now, one of the main objectives of Jewish traditions and culture has always been to promote the peaceful coexistence of peoples, beginning with peace and harmony within each family. It seems likely that, after three thousand years of considering the problem of sibling rivalry (remember the story of Cain and Abel as an example of what happens when nothing is done) the Jewish people would have developed fairly effective procedures of dealing with it, so that by the time of Jesus Christ within the Jewish culture "brotherly love" was in fact synonymous with "pure and unselfish love."

And, although it isn't particularly difficult for parents to get their children to "love one another as brothers," unfortunately the natural condition (the one that tends to happen "by itself") is the opposite one, sibling rivalry. This is confirmed by the many examples that exist of this situation.


By "sibling rivalry" we mean the antagonism or hostility between brothers and/or sisters which manifests itself in circumstances such as in the common children's family fights (which begin with a pulling of the sibling's hair or with the unwillingness to share a prized toy, and which try the patience of parents all over the world) to much more serious cases such as the permanent enmity between adult siblings, or the previously mentioned Biblical case of the murder of Abel by Cain.

It isn't difficult to find the root cause of sibling rivalry. Nature offers us many similar examples. The problem is basically one of competition for limited or scarce resources. In nature, the competition is usually for food; whenever there are two individuals or species that consume the same type of food in the same area (or habitat) they will fight with each other until one of them manages to kill or drive the other out, leaving the winner with the exclusive use of the food resources available in that area.

In nature there are some extreme cases of sibling rivalry. For example, as baby sharks develop within the mother shark's womb, the biggest baby shark devours all of his brothers and sisters, ensuring for himself all of the available food resources. In another example, eagles make their nests at great heights, in mountains or trees. The first baby eaglet that is born kills all his sibling eaglets by pushing them out from the nest as they come out of their eggs. That way all the food that the mother eagle brings will be only for him.

A similar competition exists between siblings in human families. However, here the scarce resources are the TIME, ATTENTION, LOVE and APPROVAL that the parents can give to each of their children. Looking at this situation in very simple terms, if the parents have only a certain limited amount of exclusive (one-on-one) time to give to ALL their children, it is easy to see that if there is only ONE child in that family, ALL of the parents' available time will be for that only child; if there are TWO children in the family, then each child can have HALF of the parents' time; if there are THREE children, then each child gets a THIRD; if there are FOUR, then each one gets a FOURTH of their time; and so on (In what follows, for "boy" please read "boy or girl," for "he" please read "he or she," and similarly in all like cases).

That this is indeed the case can be seen by simply looking at most families' photo albums. Looking through these albums, one can see that there are usually many pictures of the birth and first year of their first-born child. For the second child, there are fewer pictures. And, from the third child on, one may have a hard time finding pictures of them in the album - it's as if they didn't even exist!

This is the root of the problem. To examine this situation more closely, we can put ourselves in the place of each child in the family as each new sibling is born. When the first child is born, ALL of the parents' available time and attention is only for that one child. Because of this, this first child feels rather special, and he or she usually gets to spend at least one year in these privileged circumstances. Nevertheless, even this limited period of time (of only one year) has an enormous impact on that child and his or her later life. It is a common observation that, in most families, it is usually the first-born that has the greatest "success" in later and adult life.

What happens when the second child is born? To begin with, the amount of exclusive time that the parents can give to the first-born is immediately reduced to at least half of what it used to be. The true situation is even worse. A new baby requires enormous amounts of time, effort, and attention. What the first-born feels is that suddenly mom and dad hardly have any time to spend and play with him or her, and when they do, they are usually tired and irritated.

Now, a one-year-old child cannot yet reason very well - we must remember that he or she is just beginning to learn to speak. However, even at this young age, the child's capacity for EMOTIONAL feeling is already rather well-developed. And, what he or she feels is an intense DISLIKE for this new situation, and associates this disagreeable situation with the new intruder in the family (that is, with the new baby).

To compound the child's frustration, this new situation goes on and on. The first-born is not very happy with this. Remember that, for a one-year-old, one day is a very long time, and a week may seem like an eternity (The effective reality is the one that the individual feels, which is not necessarily the one that is apparent to others). To make matters worse, this is happening just as the first-born is entering one of the most difficult and frustrating life-periods, for both the child and the parents, the so-called "terrible twos." At an emotional level, the seeds of the antagonism are already sown. Part of the problem is that the human mind tends to process emotional impulses before it processes conscious thoughts (and unfortunately this is as true for children as for most adults).

Almost unconsciously, the older child begins to look for ways to try to get the parents to "stop loving" the younger one. Later, the first-born will also begin to directly irritate and bother the younger child. When the parents become aware of this, they will reprimand and may punish the older child. However, this doesn't solve the problem. Punishing the older sibling simply makes him or her develop ways to diminish, bother, and irritate the younger one that the parents won't be able to detect (Some readers may believe that this is not possible. However, children can be surprisingly creative. For example, if the younger child is still a baby, the older one can whack or pinch her while she is sleeping and make her start to cry, without either the child or the parents noticing whose hand it was. Later on, the older sibling can secretly damage or lose the younger's toys or clothing items. An even sneakier tactic is to put the younger child's things in a different place from where he left them. This makes the younger child appear careless and, if found out, the older sibling has the perfect excuse: She was just cleaning up the younger child's mess!).

Meanwhile, how does the younger sibling see this situation? When he or she first arrives at the family home, all appears to be well. There are mom and dad, who take care of him or her and try to satisfy all of his or her needs. But there is also this other someone who, without any provocation, bothers, irritates, and tries to make life impossible for him or her. At first, the younger child's capacity for action is rather limited, and he or she cannot do anything either to defend him or herself, or to attack in return. But as the child begins to grow, he or she will begin developing ways to stop or hinder the older's attacks. The easiest is to tell mom or dad: He hit me! - He took my toy! - He pulled my hair! This makes the parent scold the older child and stops the attack... for the moment. However, an important part of the problem is that, for children that are still younger than some ten years of age, a difference in ages of even just one year means a tremendous difference in size, strength, dexterity, and mental capacity. The sad truth is that, from the beginning, the younger sibling has very little chance of winning in this conflict. As he or she grows up, this continual losing against the older sibling is a source of great frustration for the younger child (Of course, younger siblings don't always lose. As they grow older, younger brothers or sisters begin to develop all kinds of tactics to block the older sibling's attacks and in turn bother and exasperate him or her... - TV-comedy writers and producers seem to find these older-younger sibling conflicts a great source of inspiration, which perpetuates the problem as children will imitate the behavior of the kid characters that appear in the TV shows they watch - Note that the extremely popular 1995 Pixar/Disney animated movie Toy Story is the story of the sibling rivalry between Woody and Buzz, and that by great luck has a happy ending).

This is one of the reasons why, to attract the parents' attention and approval, the younger child will tend to develop abilities that are different from the ones developed by the older one (If he or she tries to develop the same abilities, then he or she will never have something at which he or she is better than the older child). For example, if the older child is good at sports, then the younger one will tend to be good at school-work, and vice-versa.

Next year, another new baby arrives in the family, and another round in this game begins. This time it is the two older siblings against the youngest one. Also, this time the parents have even less time and energy to devote to each child... It isn't difficult to figure out why, in many families, it is the youngest sibling who generally has the greatest psychological problems upon reaching adult life.

         Now, something that should be pointed out quite clearly is that sibling rivalry is NOT the oldest child's fault, nor that of the other children in the family.  Also, it is NOT the parents' fault either.  The truth is that the root causes of this problem are the timeless and universal circumstances shared by ALL human families.  As mentioned at the beginning, reading the Bible one can see that this is NOT a new problem.

It should also be emphasized that the discussion presented herein is by no means a complete description of this complex problem. It is rather an attempt to point out the most important factors that contribute to this situation. There are many other modifying factors. For example, if the second child's sex is different from that of the first, then this will tend to lessen the development of the rivalry as, from the start, the second child has something special that the first child doesn't have, namely the fact of being a girl or a boy. On the other hand, if both children are of the same sex then the likelihood of the problem arising increases. Also, as is discussed in what follows, the difference in ages between consecutive children can greatly influence the development of this situation.

Continues in Part 2

eXTReMe Tracker

Visits to this page since 7 April 1999:

Donate to help disaster victims at the Network for Good website.

Please visit my guestbook:

Visit my Guestbook!

Your support is appreciated!
(Any amount is welcome!)

Official PayPal Seal

Copyright © 1999-2009, All rights reserved, by William Antonio Boyle, PhD.
Reproduction of this essay in whole or in part is freely allowed, if the source is cited (see citation example) and the author is notified at -
(You are also welcome to link to this site!)

Click here:

Do you believe that ALL parents should have enough time for their children? Click here!

; Bravenet SiteRing The Practical Parenting SiteRing

This ring owned by
Dr Andy Gill
             Site List 
             Sites Random 
             Site Join 
             Ring Next 
SiteRing by