Why Do Brothers And Sisters Look Different?


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Page last updated: 24/09/2022

Why Do Brothers And Sisters Look Different?

In this article, we will explore why brothers and sisters look different. This article explores how environmental factors and genetic makeup play a role in siblings having different appearances. This article will help you understand why you look so different from your brothers and sisters.

Why do brothers and sisters look different?

Each parent contributes a full set of chromosomes to every offspring, but the set of chromosomes from each parent is selected randomly from among the 46 chromosomes (23 pairs). The only rule is that the child receives one of each chromosome from each parent.

If somehow the child inherits all 23 pairs, he will look precisely like his father or mother, however what happens in reality is that the genes are passed on at random to the following generation.

As a consequence, each brother and sister inherits a unique chromosomal combination. There are 223 potential combinations from each parent. This is why siblings have distinct appearances. So, how about identical twins? Identical twins inherit their parents’ genes in precisely the same combination. That’s why they appear exactly similar!

We all know some brothers and sisters who look so different from each other that no one could tell that they are siblings even if they were hit in the face with that fact. In many cases, a sibling turns out to have such a distinct appearance that their brothers and sisters tease them about being adopted or in my case being picked up from a dumpster.

Environmental Factors 

Your environment, as defined by geneticists, is the way you grew up. It comprises your upbringing, where you grew up, your diet, and what you do. It also includes everything your mother did and ate during her pregnancy.

All of these factors influence your appearance. People look different in part because they did not grow up in just the same environment. Even twins are not always around each other!

Your height is one example as to how your environment can influence how you appear. There are times in your life when what you do has a significant impact on your height. When you are newly born and when you reach puberty are two of these periods.

You might be shorter if you do not eat a proper healthy diet through these two periods. However, if you eat properly, you will grow taller. Deprived children and children in war torn areas are extreme examples of this. They are usually considerably shorter than average.

There are numerous other characteristics that are influenced by the environment. Personality, stature, and IQ are only a few examples. While the environment is significant, the fact that you and your sibling inherited different gene versions from your parents is perhaps the most crucial factor in why you and your sibling look different.

Genetic Makeup 

Your genes play a significant role in determining who you are. Your genes play a role in determining your hair color, your eye color, and the dimples on your cheeks among other things.

It may appear at first that children of the same parents should look alike. After all, children inherit the same genes as their parents.

However, since everyone (even your parents) gets two copies of most of their genes, siblings don’t appear exactly alike. And these copies will differ from one another.

Why Do Brothers And Sisters Look Different?

An Example

Children inherit one of their parents’ two copies of each gene. The child’s copy is completely random. And this is one of the main reasons you don’t resemble your sibling. This is all a little vague, so let’s use an example to clarify things. Take for example, the dimples some people have.

D and d are the two variants (or alleles) of the gene that gives you dimples. The allele that gives you dimples is symbolized by the letter D, while the allele symbolised by the letter d means no dimples.

You carry two copies of the gene that may give you dimples, much like almost every other gene. When you have two D copies, it’s evident that you’ll get dimples. But two d copies indicate that there are no dimples.

But how about a D and a d copy, though? Then you’ll get dimples. D is dominant over d, or d is recessive to D, according to genetics.

So, how does this apply to you and your sibling? Let’s use parents as an example to demonstrate why this is key.

Assume your father owns a D and a d copy. He has got dimples, but he could give you the d or the no dimple copy. Since he is also a carrier of the no dimples gene copy.

The Science Behind It

How can two children with the same parents have such different appearances?

When you look at the image of a chromosome, it looks like an ‘X.’ This ‘X’ is formed by the joining of two halves. Every chromosome carries a set of genes, with two copies of each gene on each chromosome (one from the mother and one from the father). The baby’s traits are determined by the dominant gene.

There are just 23 pairs of chromosomes, however these chromosomes contain about 20,000 genes. Parents pass on chromosomes to their children rather than genes. A set of identical genes can be found in every cell of a father. The same may be said for every mother. They inherited these genes from their parents via their chromosomes.

It’s worth noting that no specific protocol is observed when loading chromosomes into a sperm cell or an egg; simply put, nature selects chromosomes at random from the father’s body. The similar process occurs with the chromosomal contribution of the mother!

Before we go any further than that with this topic, start by looking at it this way. Your physical characteristics are determined by a random assortment of genes from your four grandparents (two on the paternal side and two on the maternal side). Since this set of genes in one person can be substantially diverse, siblings from the very same parents can sometimes appear to be really different.


In this article, we explored why brothers and sisters look different. This article explored how environmental factors and genetic makeup play a role in siblings having different appearances.

Frequently Asked Questions: Why Do Brothers And Sisters Look Different

Who has stronger genes, mother or father?

As per genetics, you have more of your mother’s genes than your father’s. This is due to the mitochondria, which are little organelles that exist within your cells and are exclusively given to you by your mother. How amazing is that? You have a lot to be thankful to your mother for!

Why are siblings so different?

For starters, genetics can explain sibling differences. Siblings normally only share half of the DNA that their parents pass down to them. Secondly, even if siblings attend the same school, they may associate with distinct groups, which has an impact on their personalities. Lastly, a child may choose to act differently from his or her siblings in order to develop a distinct character.

Are siblings similar in intelligence?

Studies of intellectual similarity between siblings indicated that siblings who were closer in age had more similar IQs than siblings who were farther apart in age. This is likely due to the fact that siblings of comparable ages are more inclined to share almost the same environmental influences.

Why do siblings look different genetically?

Siblings generally carry around half of the same DNA due to recombination. Although biological siblings may share the same family tree, their genetic codes may vary in at least one of the areas examined in a test. Even fraternal twins have this tendency.

Do you inherit more DNA from your mother or father?

Men inherit roughly 51% of their DNA from their mother and only 49% from their father, but women inherit 50% of their DNA from each parent.

Does height come from Mom or Dad?

The Genetics of Height

Genes aren’t the only factor that influences a person’s height. A child’s height may be significantly greater than that of their parents or other relatives in some cases. Alternatively, they could be significantly shorter. Other factors contributing to height, in addition to your genes, might create such significant disparities.

Why are my parents tall but I’m short?

Our height is determined by hundreds, if not thousands, of different genes, some of which make us shorter and others which make us taller. It’s completely random which ones you’ll get from your parents. As a result, not every sibling is the same height. However, most are about the same height as their parents.

Is being 5’8 tall for a girl?

The average height of a woman in the United States is 5′4′′ (163 cm), thus a woman standing at 5′8′′ would be pretty tall. The average African lady is 162 cm tall, thus it would also be considered tall. 5′8′′ is quite tall in comparison to the average Asian or Latina lady, who stands at 5′1′′.

Why do members of a family look different?

Parents pass down pairs of genes to their children. One set of genes comes from the father and one from the mother. These genes can be mixed and matched in a variety of ways to create new combinations. This explains why some family members resemble each other closely while others do not.

Why do some people have traits like their grandparents but not their parents?

Genes are hereditary, which means they are passed down through generations, and each person is a product of his or her genetic makeup. As a result, if your genetic makeup is close to that of your grandparents, you will resemble them more than your parents!


Understanding Genetics

How Can Children With The Same Parents Look So Different?