Eldest Child Behavior

Birth order has been studied for decades, as parents and scientist recognized that the oldest child tends to have similar characteristics as other first-born children. However, the difference in age between siblings greatly affects if the child takes on the usual behaviors seen for their place in the family. According to Linda Sonna, in “The Everything Parent’s Guide to Raising Siblings,” if there are six years or fewer between your oldest and second child, then your eldest child’s behavior will probably have many characteristics of an oldest child 1. If there are seven or more years separating your first and second born, then your eldest child will more likely have characteristics of an only child.


The eldest child tends to be responsible. Whether they are 2 years old or 5 years old when their first sibling is born, the oldest child by default has to immediately learn some responsibility to help mom and dad. The 2 year old may be asked to bring mom and the baby a dropped pacifier or burp cloth, while a 5 year old may now have to get himself ready in the morning without help, because mom is taking care of the baby. These seemingly small requests lead to more responsible behavior in the oldest child.


Because they are often expected to be in charge of siblings, if even for a few minutes at a time, eldest children develop leadership skills. As a youngster, however, this can cause them to be bossy and controlling. They may want everyone involved in their games and activities to do things a certain way. When others ignore their directions, it can cause conflict and anger. But this is just how they are practicing those leadership skills that will serve them well as adults.

Anxious and Tense Overachievers

First-time parents are more attentive to their first child because they have the time and because they are nervous about being good parents. With first-born children, parents spend more time teaching numbers, colors, and letters at an earlier age, and they worry over small mishaps such as germs on a dropped pacifier. This leads to the eldest child having conservative and sometimes anxious and tense behaviors. They will worry more about grades and if they are doing things perfectly.

Family Size and Birth Order Behavior

Time Magazine reports that newer studies have shown that family size makes a difference in whether or not each child in the family takes on the typical behaviors of their birth order. In large families, birth order traits may not be as recognizable, as everyone has to pitch in to help. Middle children will need to help with younger siblings, thus taking on eldest child behaviors, for example. However, no matter the size of the family, the eldest child will always be the oldest and even in large families, they do tend to have many, if not all, of the typical eldest child behavior traits.