6 Traits Babies Inherit From Their Father
"He's tall like his father." "She has brown eyes like her father." "He gets his blue eyes from his dad." These are just a few things you hear people say about kids and the inherited traits that kids get from their fathers.
Whether it's physical traits like hairline, eye color, hair color, or a specific personality trait, parents are always looking for what traits their baby boy or baby girl has that resemble their own.
Related: 7 Traits Babies Inherit From Their Mother
We're going to take a look at what traits are inherited from father only, so Dad can proudly say his kiddo is just like him!
A Quick Look at Sex Chromosomes
Our genetic material, or genome, is made up of 46 chromosomes in 23 pairs. Each chromosome contains several genes, many of which are codes for your traits. You have a total of 46 chromosomes in each of your body’s cells, 23 you inherited from your dad and 23 from your mom.
The very last pair (pair 23) are the sex chromosomes, and they can be XX or XY. Some genes are found on the X chromosome, while others are found on the Y chromosome. Since females are XX and boys are XY, girls have two copies of X-linked genes because they have two X chromosomes, while boys only have one X chromosome.
Are Mom and Dad Equal With The Traits They Give Their Child?
Many of us think everything is 50/50, with each parent giving an equal amount of traits to their child. But even though we inherit 50% of our genes from each parent, how much they influence our traits varies.
One reason is that some genes are more active than others. Researchers studying mice discovered that they use more DNA passed down from their father, in fact, up to 60% of genes from Dad were more active than the ones from Mom.[1] It is likely, although not certain, that this is the same in other mammals including humans.
Another complication arises because of epigenetics, a phenomenon where our environment affects the way our genes are expressed.[2] Epigenetics plays a role in the way you look, but it also impacts your health and wellness— and these changes can be passed on to children.
The lifestyle of the father, his age, and other environmental factors that he experienced in his life affected the traits of his children. One example is if Dad had a healthy diet as an adolescent, this could reduce the risk of heart disease in his children and even grandchildren.
Dominant Genes vs. Recessive Genes
When you're talking about traits that babies inherit from their fathers, it's important to understand that there will be certain dominant traits that are more likely to appear due to the existence of dominant and recessive genes. That's what it means when we say strong genes.
Different versions of a gene are called alleles. Alleles are either dominant or recessive depending on their associated traits. If you’ve taken high school biology, you may already be familiar with the genetic principles of Gregor Mendel and Mendelian genetics. Mendel worked during the 19th century to establish the fundamental laws of inheritance.
The Laws of Inheritance Found That:
- Each inherited trait in a child is defined by a gene pair where offspring inherit one genetic allele from each parent when sex cells unite in fertilization.
- Genes for different traits are sorted separately from one another so that the inheritance of one trait is not dependent on the inheritance of another.
- Someone with alternate/different forms of a gene from both the mother and father will express the dominant form.
Dominant genes let their presence be known even if it comes from only one parent. Whereas recessive genes would have to be present in both parents for the baby to end up with the trait they carry.
Some Common Examples of Dominant Traits Include:
- Dark eyes are dominant over light blue/green eyes.
- Curly hair is dominant over straight hair.
- Dimples and freckles are dominant over lack of these features when the dimples gene is present.
With all that said, can a person look at their family history and appearance to predict what their future children will look like? Sort of. For men and women, different traits are more likely to be dominant.
What Genes Are Inherited From Father Only?
When we think of inheritance, our minds often jump to the physical traits passed down from parents to their offspring. However, genetics play a fascinating role in determining much more than just eye color or height. In the captivating realm of inheritance, fathers contribute a unique set of genes that can shape various aspects of their children's lives, from personality quirks to innate talents.
1. Height
If your dad is tall does that mean you’ll be tall as well?
Physical characteristics and physical appearance as a whole are heavily biased toward the father's genes and not the mom's genes. Your adult height is influenced by your parent’s genetics, but it’s not as simple as just having a “tall gene” run in the family.
There are at least 700 genetic variations that are responsible for determining height.[3] While this trait comes from both mom and dad's genes, there is evidence to show that a dad's genes play a greater role in the height department.
Researchers look at the insulin-like growth factor (IGF protein) when talking about height. This is the genetic trait that is responsible for promoting growth. A woman's genes have a contradictory receptor called IGF2R.
The imprinted gene is marked by the origin parent from the beginning. It marks mom's copy and dad's copy of the allele. The stamped gene and inherited trait are expressed differently. It depends on which parent they came from, or if they're only inherited from one parent and not the other. The father's IGF genes can help a child grow tall while the mother's IGFR2 genes can stunt growth.
2. Biological Sex
If Dad's ever disappointed by not having a little boy or girl, that's on him! Men are responsible for determining the biological sex of a baby. (So there, Henry VIII!) Men contribute a Y chromosome for boys and an X chromosome for girls.
According to medical research, a man's X and a woman's X combine to become a girl, and a man's Y combines with a woman's X to become a boy.[4] But if the sperm don’t have equal Xs and Ys, or if other genetic factors are at play, it can affect the sex ratio.
Researchers also found that the sex ratio for families followed the father's side, not the mother's side. For example, if a man had more brothers, his own children were more likely to be male; if he had more sisters, he was more likely to have daughters. However, this link was not the case for women.
3. Mental Health Issues
Genetics also plays a role in someone’s brain chemistry. If a man becomes a father later in life, there is less quality sperm. This is one of the reasons why older fathers can pass on mutant genes to their children which can lead to mental illnesses or mental health issues.[5]
This means children can develop conditions such as hyperactivity or bipolar disorder. Children born to parents over 45 can also be more likely to have learning difficulties and perhaps suicidal tendencies.
However, recent research has noted that genetic influence on mental disorders may be less strong than previously thought. Mental disorders have a genetic link, but it is only 10-20% with a variety of other factors influencing mental health.
4. Y-Linked Disorders (Like Webbed Toes!)
Because boys have the sex chromosome XY, they must inherit their Y chromosome from their father. This means they inherit all the genes on this chromosome, including things like sperm production and other exclusively male traits.
It also means they will get any disorders caused by mutations in genes on the Y chromosome. These are called Y-linked disorders.[6] There aren’t many, as the Y chromosome is small and doesn’t contain many genes, but they include hypertrichosis of the ears—a condition where there is more hair than usual on the outer ear—and webbed toes, a condition where the second and third toes are joined by a web-like connection.
5. Personality
Some personality traits like intelligence, whether you are an introvert or extrovert, and temperament do have a genetic component and so can be inherited. In fact, studies using twins have shown that some personality traits are 30-60% heritable. So, a man can expect his children to inherit some of the genes that give him his personality traits.
However, environmental factors also have a big influence on personality. For example, having a calm Dad could result in you also growing up calm, simply because of the environment you were brought up in and not because of the genes you inherited from him.
6. Fat Storage
Our bodies contain two different types of fat. We use brown fat as a source of energy, but white fat is stored in our body, so too much can cause health problems such as obesity and heart disease. Researchers have shown that how much brown fat you produce is inherited from your mother, while white fat storage is inherited from your father.
This means that Dad’s genes are more likely to contribute to fat storage. However, as with many traits, environmental factors play a big part so having an overweight Dad doesn’t necessarily mean the same fate for a baby in the future. Our lifestyle plays a big role in health, no matter what genes we inherited from our parents.
Why Does My Baby Only Look Like Their Dad?
If you’ve ever looked at a baby and thought they looked just like a mini version of Dad, then you are not alone. In fact, this is a long-standing belief and one that scientists thought might have an evolutionary basis.[7] It stands to reason that Dads would take better care of babies that looked like them.
However, research has shown that this is not the case—people might think that the baby looks more like Dad but that is all it is—a false perception. Babies do resemble both parents equally, as the genetics suggest.
Interestingly, Dads start to think that their baby looks more like them the longer they spend with them. It seems that getting to know their baby’s facial cues more intimately can change how Dad perceives his child.
The Bottom Line
The next time you look into your baby's dark eyes or wonder how they got so tall, you can thank their father! There are many traits babies inherit from their fathers as well as many traits they can thank their mothers for.
There are also many personality traits that babies will develop as they go along in life. Whether your baby is the spitting image of dad, just like mom, or a mix of both parents, the important thing is to embrace all sides because every trait makes up the little person that is your baby girl or baby boy.
Wondering what type of personality your baby will have? You or your partner's? Check out this genetic explanation of how personality is determined.
