4 Reasons Why Toddler and Preschooler Tantrums Happen: The Science Behind the Outbursts

Written By

Shannon Wassenaar
July 26, 2023

This article has been reviewed by Nurtured First’s team of child development experts.

The bath is too wet.

The trees are too green.

The blanket is too fuzzy.

Tantrums are often confusing to adults. It can feel like there’s no reason for a tantrum.

When my oldest started having tantrums, my husband struggled. He grew up in a home where big emotions were punished, and he would get into trouble for having a tantrum. 

One day we were on a drive, and he started asking me what we could do to help our daughter have less tantrums. Did she need punishment? How should we respond to her tantrums?

As we drove, I explained to him the science behind toddler tantrums. I explained to him that tantrums are important and that our daughter needed our calm, not our punishments, to learn how to regulate through tantrums.

When he understood that tantrums weren’t bad and, instead, were an incredibly important part of child development, the way he saw our child changed. He started viewing tantrums as opportunities to teach our daughter new skills.

In this blog post, I will share four reasons why toddlers and preschoolers have tantrums. This will help you understand why your child is struggling so you can help them learn new ways of coping with their feelings! 

Reason #1: Their Brain Isn’t Fully Developed

To understand why tantrums happen, we need to consider their cognitive development and peek into our child’s brain. To keep it simple, we’ll refer to two parts of the brain: what we’ll call the logical brain (the prefrontal cortex) and the emotional brain (the amygdala).

The logical brain (prefrontal cortex) is responsible for logical thinking and emotional regulation. Children need to be able to think logically to regulate emotions. But, this part of the brain doesn’t start to develop until a child is five-seven years old. For some kids, it develops even later, at around eight-nine years old. This explains why children younger than five, like babies, toddlers and preschoolers, are especially impulsive, emotional, and illogical. Young children can’t access logical thinking because that part of the brain is under active development.

The emotional brain (amygdala) is responsible for automatic functions, like breathing, blinking, responding to danger, and emotions like fear, anxiety, worry, shame, and anger. It’s developed at birth, and is responsible for all of your toddler’s big feelings! 

As a child ages towards the 5+ range, their brain grows and expands. All this growth helps your child reach new cognitive developmental milestones. Understanding how a child’s brain works and the average ages for these milestones can help caregivers make sense of their child’s outbursts and behaviours.

Ages and Stages of Cognitive Development

Child’s AgeBehaviours
1-2 years old– Starting to express frustration when demands aren’t met.
– Tantrums when others interfere with activities; possessive of items. 
– Emotional outbursts when unable to articulate wants/needs.
– More frequently asserting independence.
– Often refuses to cooperate.
– Starting to have tantrums when tired or frustrated.
2-3 years old– Frequently tests limits.
– Says “no” often.
– Frequently asserts their independence.
– May use physical aggression when frustrated or angry.
– Impatient; difficulty taking turns or waiting.
3-4 years old– Insists on doing things independently.
– Tantrums when things don’t go the way they want.
– Often tests the boundaries.
– Inflexible; upset when the routine changes.
– Frequent verbal and physical pushback.
– Difficulty coping when things don’t go their way.
5-7 years old– Increase in ability to control impulses.
– Talks self through simple problem-solving.
– Generally cooperative with caregivers.
– Increased frustration tolerance.
– Generally able to participate in group activities and turn-taking.
– Starting to understand the link between cause and effect.
– Able to control emotions better.
– Periodic mood swings. 
– Easily disappointed and frustrated with self. 
– Difficulty seeing others’ perspectives. 
– Difficulty determining moral standards; relies on rules. 
– Increasing fears (e.g. the dark, strange noises, animals). 
8-9 years old– Ability to solve more complex problems.
– Can think through things logically.
– Ability to recognize others’ perspectives.
– Ability to communicate feelings.
– Increased frustration tolerance.
– Effective coping skills for anger and frustration.
– Understands the effect of behaviour on others.
Note: These are general guidelines. Some children will meet these milestones earlier or later than the chart suggests (e.g. Highly sensitive children often reach the milestones later.)

Reason #2: They’re Still Learning Emotional Awareness and Regulation

The next important part of understanding why your child has tantrums is to consider your child’s emotional development.

Emotional development is the process of learning how to understand your feelings, why they occur, and how to cope with them. This is often referred to as emotional awareness/intelligence or emotional regulation. 

Toddlers and preschoolers haven’t developed emotional awareness and emotional regulation skills. This doesn’t start to happen until they are between the ages of five-seven. In the meantime, their caregivers need to lend them their calm. 

So, if you have a toddler or preschooler who is having emotional outbursts, from an emotional developmental perspective, this makes sense!

Here are two common situations where it’s evident that toddlers and preschoolers aren’t emotionally developed yet, and can help you understand why they’re having a tantrum.

1. When boundaries create bigger tantrums

Toddlers and preschoolers are little scientists driven by curiosity. This curiosity drives them to test the limits. They test the limits to make sense of their world and to learn who to trust, what to trust, and the consequences of their actions. Exploration is their way of meeting some of their emotional needs because it connects them to their environment. 

However, limits can feel very frustrating to a child because they don’t have the ability to understand why the limits exist; the part of the brain that can reason is still under construction. 

They want to be in charge. They want to do what they want to do when they want to do it.

Here’s what your little scientist might be thinking: “I want to throw this macaroni off the highchair and see what happens. I wonder what my parents will do. This is so cool!”

When you set a boundary, like, “food isn’t for throwing” or “food stays on the tray,” it might trigger a tantrum because your toddler isn’t emotionally developed enough to understand the boundary or why the boundary is necessary. 

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2. When tantrums are used to communicate

Without emotional awareness and intelligence, toddlers and preschoolers struggle to communicate their feelings. Tantrums may serve as a way to release pent-up emotions and draw a caregiver’s attention, so they can get their needs met. 

A tantrum might be their way of communicating: 

“I’m feeling angry because my brother took my toy!”

“I’m feeling disconnected from my parents, and I need more time with them!”

“I’m feeling overstimulated, and I need a break!”

Reason #3: They’re Tired, Hungry, or Overstimulated

As I explained tantrums to my husband, we thought about the most common times our daughter would have a tantrum. In most cases, tantrums happened when she was tired, hungry, or overstimulated. 

We started smiling. Not because it was funny, but because we, as adults, have our own version of a tantrum when we are tired, hungry, and overstimulated as well!

Tantrums when tired

Similar to how parents get grumpy, irritable, annoyed, or more easily frustrated when we’re tired, toddlers do too. When toddlers are overtired, they may have a harder time controlling their impulses and may have more tantrums. This lack of impulse control can contribute to impulsive actions, like hitting their sibling during a tantrum. A rested child will be much less likely to have tantrums

Tantrums when hungry

Have you ever noticed how a toddler or preschooler can go from 0-100 right before meal times? If you have a “hangry” toddler, you are not alone (many adults even get a bit angry when they are hungry). When blood sugar levels are low, it can result in decreased energy, and a harder time controlling emotions and impulsive behaviour. Providing your child with filling snacks between meals can really help with tantrums!

Tantrums when overstimulated

Sometimes your child will have more tantrums when it’s been a busy day, or your house has lights and sounds going on everywhere. This is because overstimulation can lead your child to feel a sense of “too muchness” in their body! All the lights, sounds, and activity feels like too much! So, they need to release this “too much” feeling through a tantrum.

Note: If you have a highly sensitive child, the feelings of fatigue, hunger and overstimulation can be experienced much more frequently and intensely than other children. 

Reason #4: Their Environment Is Chaotic

The environment surrounding a toddler influences the frequency and intensity of their outbursts. A chaotic environment can be challenging for kids to navigate. When this is the case, caregivers might see more, really intense tantrums. 

A chaotic environment often occurs in two ways:  

1. Chaos in the routine

Kids thrive in predictable environments. It helps give them a sense of control. Sudden changes in their daily routine, such as a disrupted nap schedule, a parent travelling for work, moving to a new home, or adding a new baby, can feel chaotic. 

These changes and feelings can trigger tantrums if a child is struggling to adapt to the new situation and trying to regain a sense of control and predictability. You might notice more intense and frequent tantrums when:

  • A new baby arrives, so the morning routine changes. 
  • You move to a new home, so the toys aren’t in their usual spot.
  • Caregivers separate or divorce, so they spend time in two different homes.
  • A caregiver is away for work, so the environment at bedtime feels different.
  • There’s a loss of a loved one or relationship, so someone is unable to visit. 

2. Chaos in caregiving 

When there are no clear rules or boundaries in place, or there are different rules between a child’s caregivers, it can make toddlers and preschoolers feel out of control. When a child doesn’t know what to expect, it will feel chaotic to them. 

For example, when a child hits, they may be getting different responses depending on their environment.

Environment: Grandparent’s House
Response to hitting: “Don’t hit your sister!” The grandparent spanks the child.

Environment: Preschool
Response to hitting: “We don’t hit each other in this class.”  The child is sent to a time-out.

Environment: Home 
Response to hitting: “You’re having a hard time keeping your hands to yourself. I will hold them till you can use them more gently.” The parent holds gently holds the child’s hands.

As you can see from this example, there are times when children are getting conflicting messages about their behaviour when they’re in different environments. Receiving three different responses for behaviour can be extremely confusing for a child. Different expectations and reactions can feel chaotic. When toddlers and preschoolers feel lost, they are going to burst with emotion!

Related Post: 3 Expert Tips to Confidently Set Boundaries

What This All Means

1. Tantrums help children cope

Tantrums are an important part of a child’s emotional development. As a temporary release of a child’s pent-up emotions, tantrums serve as a unique way to communicate their distress and get support from their trusted caregivers. Over time, tantrums help children to gain more understanding and awareness of their feelings and lay a foundation for their emotional intelligence and resilience. 

As important as it is for kids to release their big feelings, we also want to teach our children more effective ways to express their emotions and other ways to cope. After a tantrum, when your child is calm, is the perfect opportunity to do this!

2. Should I just let my child have tantrums?

After explaining the science behind toddler tantrums to my husband, there was only one lingering question left… 

If tantrums are developmentally normal, our kids need to have them, and they are important – should we just let them have tantrums and cry and cry? 

He wondered if there was room for consequences and what to do if our kids hit or bite during a tantrum.

Here’s what is really important for parents to remember: Our job is to allow our kids to experience their feelings. When we say yes to their feelings and allow them to release their tears, it helps them move forward. Saying yes to your child’s feelings also teaches them that you are a safe and trusted person to come to with all of their feelings. 

And, we need to remember that their brains can’t control their impulses when they’re upset! That means our kids need us to step in and help them when they’re hitting, biting, or kicking. We do this by setting boundaries around our kids behaviour

3. Your child is good

Next time your toddler or preschooler has a tantrum because the bath is too wet or the blanket is too fuzzy, consider the developmental, emotional, physiological, and environmental factors that can play a role in triggering tantrums.

Your child isn’t bad; they are a good child having a hard time! 

Understanding the reasons tantrums happen can help parents respond more effectively and compassionately to their children’s needs.

For specific tools and strategies for tantrums, disciplining effectively and reframing challenging behaviour, check out our online Parenting Little Kids course!

Key Takeaways

  • Tantrums are not bad; they are an important part of your child’s development.
  • Toddlers and preschoolers have an underdeveloped prefrontal cortex (their logical brain), making them impulsive, emotional, and illogical. Their ability to regulate emotions and think logically doesn’t start developing until later (around ages 5-9).
  • Young children are still learning how to recognize, understand, and cope with their feelings. Tantrums can occur when they struggle to articulate their needs.
  • Tantrums often happen when a child is tired, hungry, or overstimulated.
  • Changes in routine, a chaotic environment, or inconsistent rules and boundaries can make a child feel out of control resulting in more tantrums.
  • Tantrums allow a child to release pent-up emotions, signalling they need support from their parent or caregiver.
  • While it’s essential to let a child experience their feelings, boundaries are necessary – especially when their actions involve hurting others or themselves. Parents should step in and set boundaries in these situations.
  • Your child is a good child who is having a hard time.

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    Article By

    Shannon Wassenaar
    Shannon is a Registered Psychotherapist, Content Specialist, and Highly Sensitive Parent with a passion for understanding, and promoting human relationships. Shannon holds a Bachelors degree in Psychology, and a Masters degree in Psychotherapy. She began her professional career as a trauma therapist, and continues to support families from a trauma-informed perspective. Shannon uses her knowledge and experience to create educational content for parents, and treatment plans to help families flourish. In her spare time she enjoys taking long walks, playing recreational sports, and sipping a hot latte at a local cafe.