Significant Behavior and Brain Markers of Only Children

The majority of children grow up surrounded by siblings and cousins. Families, however, have been decreasing in size for quite some time. It is quite common to hear of your grandparents tell the tales of living in a family with seven or eight children. Modern families rarely have more than three children. Most parents agree that children need at least one sibling to grow up with. Parents that were once the only child are often even more adamant about producing a sibling or two for their offspring. While it might be fun to never have to share your candy or your room, being an only child can bring about some significant changes in behavior, and in the brain.

Gray Matter

Only children definitely look at the world differently. There are a ton of circumstances that never come up when there are no other children in the home. Experiences shape the brain. Over time, connections are made that help us deal with others around us. By our early 20s we should be able to fully display empathy and understand consequences. These behaviors, however, have a lot to do with particular parts of the brain.

MRIs were a part of a study on children in China. Half of the group grew up with siblings, while the other half grew up as only children. Gray matter volume (GMV) was something that surprised the researchers. Neurologically, the group of only children showed an increase in the amount of gray matter. The area that was most affected was that of the supramarginal gyrus volume. This area has been hypothesized to affect discernment of language, and language processing. This discovery also correlates to the greater flexibility of thinking in the only children. Flexibility in thinking determines that a person has creative talents.

Other Areas of the Brain

It is well-known that only children have less opportunities to practice their people skills. The medial prefrontal cortex in only children showed less volume. This part of the brain is associated with many behaviors that affect our everyday lives. Regulation of emotions is one of the things that stems from this part of the brain. Emotions may run high in kids that grow up alone. Social and personality behaviors also take hints from this part of the brain. The only children scored much lower on the test for agreeableness. This finding matches up perfectly with the lack of matter in the medial prefrontal cortex.


Scientists think that some of the behavioral changes take place due to external sources. Parents often act differently when there is only one child involved. Creativity may be encouraged more in small families. Parents of only one child are able to afford more things, like dance and music classes. They may also put more effort into educating their only child about art and other subjects. Expectations to succeed may also be heightened when only children are concerned. These conscious efforts by the parents contribute to the experiences of an only child. The brain develops according to what it is exposed to.


The lack of agreeableness in only children as adults may stem from the way they are approached by parents. Only children still go to school and participate as a part of the community. This, however, is not enough exposure to cement certain social skills into the brain. Parents may also be countering social exposure with their doting on the only child.

Only children may come from a situation where the parents had difficulty having kids. This leads to a lot of extra attention focused on the one child. Parents with multiple children often spend more time trying to stay organized and playing referee. The extra attention from parents may also be mimicked by other parts of the family. Aunts and uncles may share the enthusiasm. It is undeniable that only children spend a lot of time entertaining themselves. This time alone gives them the ability to be more creative but does not allow for practice solving conflicts. The less agreeable nature of only children may come from lack of social activities outside the home, as well. When you are used to doting family members, and have minimal interaction with others, compromising skills are limited.

Social Skills

Only children may be unable to practice their social skills at a young age, like those with siblings. Even if they attend some childcare situations or have company on a regular basis, there are some skills that come from the daily interaction of a sibling. By the time the child starts school they may be so out of practice that the school environment is difficult to navigate. There is a degree of conflict resolution that only comes from living with another child. Only children may have a difficult time when presented with disagreements and when being asked to compromise. In a group setting, this can cause some issues.

Leave Me Alone!

Only children also grow up in a quieter environment. They may get overstimulated easily once they start to spend more time around groups. Only children are possibly more creative because they spend a lot of time playing by themselves. They have to use their imagination more. They also become great at entertaining themselves. Only children are often able to sit and read for long periods of time. They have great perseverance when it comes to solitary situations. This can make a busy household daunting for them, later in life. When these kids become parents or get married, they may feel the need to run and hide on a regular basis. They get used to spending time alone and learn to enjoy it.

Only children have a special set of skills that comes from their environment. They may be treated differently by parents and other family members. This onslaught of attention can make them somewhat difficult later on, as they do not like to compromise or share. Only children, however, learn to create interesting playthings and use their imagination. Social skills may be lacking, however, only children have a lot to offer the community.

Editor's Picks

reset password

Back to
log in