Where does your baby’s personality come from?

Is he calm or agitated? Curious or reserved? Your baby is born with his own temperament, but that’s just the beginning. Even though genetics do play a role, everything your child experiences, sees and hears influences him and contributes to gradually building his character and personality.


One of a kind

From birth, your child reacts to situations and expresses his needs in his own way. His temperament is already evident!

By Nathalie Vallerand

From birth, your child reacts to situations and expresses his needs in his own way. His temperament is already evident!

Your child’s temperament determines how he will react, adapt to situations, express and control his emotions and also how he will connect with others. In short, the way your baby behaves will largely depend on his inherited temperament.

But even if it is present from birth and based on genetics, each child’s temperament is unique to him. Brothers 5-year-old Eliot and 3-year-old Zack are a case in point. The eldest was a calm baby, who didn’t cry or smile much. “It was a little harder to connect with him,” remembers mom Émilie. “He was a serious tot.” Zack was more expressive. He babbled a lot and smiled at anything. Today, he’s an adventurous little boy who gets excited by anything that’s new, and he has a hard time staying still. Eliot is still just as serious as he always was. He’s loving, helpful and a little shy, and he also has an excellent attention span.

The characteristics of temperament

The words used by researchers to explain temperament are not always the same, but generally speaking, there are two main components to a child’s temperament:

  1. Reactivity. For example, how a child reacts to novelty (food, places, people, activities, objects, etc.) is an aspect of his temperament. Is he happy, hesitant or cranky? The ability to adapt to change also falls under this category. Some babies adapt quickly, others, more slowly. Temperament can also be expressed as moods. Some children smile more and are often cheerful. Others express more negative emotions; they cry, and they’re irritable and angry.
  2. Ability to control impulses. This is a child’s ability to self-regulate, meaning, for instance, to resist the temptation to touch a forbidden object, to do something he doesn’t really feel like doing, or even to stay calm in a public place. This aspect also refers to his ability to concentrate and pay attention. When a child performs an activity that requires concentration, is he easily distracted by noise or by what’s happening around him? Can he stay focused on a task for a long time? Does he follow rules easily? The ability to control himself will develop throughout his early childhood years.

Can your baby change?

Little 10-month-old Loïc is usually in a good mood and seems happy when facing novelty. “When we bring him to a new place, he smiles and fidgets for us to let him go and explore,” says dad Jean-Sébastien. Despite his young age, the little boy is even starting to be able to control some of his impulses. For example, his parents let him handle their mobile phone, but they don’t want him to put it in his mouth. “Lately, he’s been bringing it up to his mouth, but then he looks at me and waits for my reaction,” says his mom, Rachel.

Loïc’s temperament and the way his parents care for him influence one another. Studies have shown, for example, that parents have an easier time warming up to children who are happy or who follow rules. This reaction is understandable since “a child with an easy temperament makes parents in some way feel rewarded for the care they provide,” explains Catherine Ruth Solomon Scherzer, a professor with Université de Montréal’s Psychology department.

On the flip side, children with more difficult temperaments (who often cry or have temper tantrums) can discourage parents or try their patience. Again, this reaction is normal since these children are more demanding for parents.

Even if a child’s reactions and behaviours are difficult, you need to understand that his temperament isn’t written in stone and that it doesn’t determine his future. “With a positive attitude, parents can help their toddlers improve their temperament,” explains Andrée-Anne Bouvette-Turcot, PhD student in psychology at Université de Montréal. “Temperament evolves with experience,” she says. “A child with a very reactive temperament can, in fact, learn to calm his more intense emotions if his life environment is stimulating and reassuring, and if he has a strong sense of attachment to his parents.”

Knowing how to adapt to your child

Even if it doesn’t completely disappear, a more challenging trait can become less apparent. For example, an impulsive child can learn to better control his impulses. As a parent, you can help your toddler improve his temperament. “It might, for example, be tempting to ignore the tears of a baby who cries a lot and who is difficult to comfort, but what this type of baby is more likely to need is a quick and warm response to feel reassured,” says Ginette Dionne, professor at Université de Laval’s School of Psychology. When parents answer this need by rocking their baby, rubbing his back or cuddling him, they teach him that he can trust them in addition to strengthening the child’s sense of attachment to them. On the other hand, if they ignore their baby, he risks becoming even more irritable and impatient.

It’s possible to tone down a baby’s angry and fearful temperament by being calm, warm and reassuring.

The same goes for a child who often gets angry. “If you get angry back, you risk encouraging this troublesome behaviour,” says Catherine Ruth Solomon Scherzer. It’s best to try to remain calm, instead, and to talk to him once the tantrum is over, to help him put what he is feeling into words.

Adapting your reactions to your child’s temperament can also help him learn to live in society. This is what 5-year-old Eliot’s parents observed when he started to be afraid of new things. Instead of overprotecting him, they tried to build his confidence by reassuring him and encouraging him to press forward. “Before he started his skating lessons, we prepared him by explaining to him what to expect,” says dad Cédric. Mom Émilie adds, “When we’re at a restaurant or with a person he doesn’t know very well, we also encourage him to speak for himself. This summer, we sent him to buy some bread by himself at the campground convenience store. He was so proud. In fact, he seems to have gained confidence these last few months.”

Many characteristics are developed in mommy’s tummy. This is as true for physical traits as it is for psychological traits. Researchers from the Douglas Mental Health University Institute have shown that the mental health of the expecting mom can change the ways the genes work in the unborn child. The pregnant woman’s mood affects regions of the baby’s brain that are linked to stress and emotion control. So when an expectant mom is depressed or overly anxious, the baby she is carrying has a greater risk of suffering from anxiety, stress and even attention deficit after birth. The good news is all this can change. If mom gets better, the child receives the appropriate care and grows up in a loving family, then his mental health is less likely to be affected.

Also, if your child has a very active temperament, the best thing to do is to provide him with ample opportunities to move, especially before outings or activities where he’ll need to stay still. This could help him develop his ability to stay calm when required.

Personality in the making

Your toddler’s temperament is present from birth, but her character and personality develop over time.

Your toddler’s temperament is present from birth, but her character and personality develop over time.

Character is usually defined by someone’s way of being and how they behave. “Character is forged from both a child’s temperament and her life experiences,” explains Ginette Dionne, a professor with Université Laval’s School of Psychology. “Temperament and character become closely linked very quickly making it difficult to separate what is inherited from what is acquired through experience and relationships with others.”

Take the case of Loïc. He’s only 10 months old, but already he’s a prankster. “He pretends to bite my nose because he knows that I’ll exaggerate my reaction to make him laugh,” says dad Jean-Sébastien. “He likes having fun, just like his mother and I.” For her part, 2-year-old Eugénie is as stubborn as her mom Valérie and her grandfather. “When she wants something, she tries to get it by any means possible,” says Valérie. Family trait or learned behaviour? It’s probably a bit of both!

The influence of environment

The environment in which your child grows up plays an important role in the development of her character and personality. Identical twins are a good example of this. They are born with a similar temperament since they share the same genetic baggage. Most often than not, they also grow up together. In theory, then, they should have the same character. Well, not necessarily. Each will have his or her own, because each of their life experiences will be different. “Even though parents aren’t always aware of it, they act differently with each of their children,” says Dionne. “And twins don’t always have the same friends or the same teachers. They don’t necessarily do the same activities, either. Simply put, each has different life experiences. It’s this variety of experiences that helps them gradually develop their own personalities.”

And it’s not just the family and immediate community who forge a child’s character and personality. Society plays a role as well. For example, sexual stereotypes can encourage girls and boys to behave according to the characteristics associated with their gender. It’s also been proven that stereotypes partly determine the attitude parents have towards their children. Everything your child sees, hears and experiences influences how her personality will develop.

Personality develops until early adulthood.

Finally, although not always easy, it’s better to avoid describing a child with negative characteristics. For example, avoid saying: “You’re annoying,” “You’re a liar” or “You’re difficult.” That’s like labelling your child and boxing her into a specific role. “The more she hears that she is like this or that, the more she’ll end up believing it,” says Catherine Ruth Solomon Scherzer. “If you say she’s annoying, then she’ll be annoying.”

Does birth order have an impact?

Contrary to what we often hear, a child’s birth order does not influence her personality much. The eldest in a family is not always responsible and organized. And the youngest is not always a charmer who dislikes responsibility! Birth order is certainly one of the aspects involved in the development of personality, but its influence is limited, according to a recent American study. Conducted among 377,000 youth, the study revealed that the eldest are slightly more serious, agreeable and assertive and less anxious than the other children in the family, but these differences are so small that they practically have no impact on a person’s life.

Genetic or not?

Besides temperament, what other characteristics does your child inherit? Science still hasn’t uncovered all the secrets of genetics, but here are a few answers.

Besides temperament, what other characteristics does your child inherit? Science still hasn’t uncovered all the secrets of genetics, but here are a few answers.


This one remains a mystery! There is no intelligence gene. Several genes are no doubt involved, but most of them have yet to be identified. The environment (family, daycare, school, etc.) also plays a role in the development of a child’s intellectual abilities. Your toddler’s intelligence therefore comes from both her genes and her living environment.


Yes, there are certain genes that predispose a child to obesity. This is why several members of a single family are often obese. According to the Research Chair in Obesity at Université Laval, the risk of carrying extra pounds is 2 to 8 times greater in people who have obesity in the family. But heredity isn’t the only factor. Behaviour and life habits can also increase or decrease the risk.

The character of adopted children

A child is born with a temperament that is largely inherited. But this temperament can change according to her living environment and the way she is raised. A child’s experiences after adoption strongly influence the development of her temperament and character. It is therefore likely that the toddler you have welcomed into your heart and your life will take after you in many ways!


You might be surprised to learn that genetics isn’t always involved in conceiving twins. There’s no genetic factor that explains the conception of identical twins (babies coming from the same egg). In such cases, it’s simply the luck of the draw. Genetics does, however, play a role in the conception of fraternal twins, which are the result of two eggs fertilized by two sperm cells. This type of pregnancy occurs in women who produce several eggs per cycle, which is an inherited characteristic. This is why women who have fraternal twins in the family have a greater chance of conceiving them as well.

Who does your child look like?

Your baby has mommy’s green eyes and daddy’s brown hair. A child’s physical appearance mostly comes from her parent’s genetic baggage, but it’s also a bit of a game of chance.

Your baby has mommy’s green eyes and daddy’s brown hair. A child’s physical appearance mostly comes from her parent’s genetic baggage, but it’s also a bit of a game of chance.

Are you expecting a child and wondering what colour her eyes will be? Statistically speaking, chances are high that they’ll be brown, as this is the most common eye colour in the world. That said, eye colour is most definitely an inherited trait. For a long time, we believed it to be a simple question of dominant or recessive genes, where the brown-eye gene was more dominant than the blue. So for a child to have blue eyes, it was thought that she had to have received two blue-eye genes from her parents (one from dad and one from mom). A blue-eye gene and a brown-eye gene, or two brown-eye genes resulted in brown eyes. Now, however, recent studies have revealed that the reality is a lot more complex.
Some inherited traits (e.g.: black skin, blue eyes) can skip one or several generations.

Eye colour depends on several genes, of which some are mutations. It’s the combination of the mutations and the interaction between genes that determine the colour.

This is why there are so many varying shades of eye colour: brownish-green, hazelnut brown, blackish-brown, grey, bluish-grey, etc. So, even though rare, it is possible for two blue-eyed parents to conceive a brown-eyed child. It’s therefore impossible to predict with any certainty the eye colour of an unborn child. One single mutation of a gene and the colour can change!

Many physical characteristics can also be explained by the combination of several genes. Take skin colour, for example. If one parent is white and the other, black, their child’s skin colour can vary by several shades, from lighter to darker. Height is another characteristic that depends on several genes and even some environmental factors such as nutrition. With regards to hair colour, that’s also the result of more than one gene. There are an infinite number of possible shades, but genes for dark hair (brown, black) generally tend to have the upper hand over genes for blond or red hair.

In short, we can never know in advance whom a baby will look like. The one thing that is certain is that your baby will be one of a kind and probably also the most beautiful person in the world… at least to you!


  • Genetics, family, friends and society all influence personality development.
  • You can help your child by adapting your behaviour and requests to her temperament.
  • Physical characteristics come from a combination of several genes.
Naître et grandir

Source: Magazine Naître et grandir, November 2015
Research and copywriting: Nathalie Vallerand
Scientific review: Jean-Pascal Lemelin, professor with the Department of Psychoeducation at Université de Sherbrooke, and Dr. Bruno Maranda, medical geneticist at the Centre hospitalier universitaire de Sherbrooke

Photos: Maxim Morin, Martine Lavoie and iStock