What does a two-year-old's defiance look like, and why does it happen?
Applies to age: 24–36 months
In short
Tantrums usually start around 18 months of age and are very common; hitting and biting are also common. One reason is that the child wants to express themselves but finds it difficult; the frustration comes out as a tantrum.
What is normal
All claims: international norm
- Tantrums usually start around 18 months of age and are very common in young children.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
Temper tantrums usually start at around 18 months and are very common in toddlers.
NHS · open the source · accessed: 2026-10-09 · license [1]
- Hitting and biting are also common.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
Hitting and biting are common, too.
NHS · open the source · accessed: 2026-10-09 · license [1]
- One reason is that young children want to express themselves, but find it difficult.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
One reason for this is toddlers want to express themselves, but find it difficult.
NHS · open the source · accessed: 2026-10-09 · license [1]
- The child feels frustrated, and the frustration comes out as a tantrum.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
They feel frustrated, and the frustration comes out as a tantrum.
NHS · open the source · accessed: 2026-10-09 · license [1]
- A tantrum may be caused by the child being tired or hungry.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
Your child may have a tantrum because they're tired or hungry, in which case the solution could be simple.
NHS · open the source · accessed: 2026-10-09 · license [1]
- The child may also feel frustrated or jealous, for example of another child.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
They could be feeling frustrated or jealous, maybe of another child.
NHS · open the source · accessed: 2026-10-09 · license [1]
- When a child can talk more, they have tantrums less often.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
Once a child can talk more, they're less likely to have tantrums.
NHS · open the source · accessed: 2026-10-09 · license [1]
When to worry
All claims: international norm
- If a child's behavior seriously worries the parent, it is worth seeing a doctor about it.
Source: NHS – show the original wording (EN)
Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:
If you're seriously concerned about your child's behaviour, talk to your health visitor or GP.
NHS · open the source · accessed: 2026-10-09 · license [1]
See a doctor
- It is worth discussing with a specialist what worried the parent, and using the advice of a midwife, a nurse or a pediatrician.
Source: Portal Pacjenta – show the quote
Verbatim quote from the source:
Polish original
Warto jednak skonsultować ze specjalistą to, co Cię zaniepokoiło i korzystać z rad położnej, pielęgniarki czy pediatry.
Portal Pacjenta · open the source · accessed: 2026-10-09 · license [2]
international norm “International norm” next to a section heading means its claims come from a non-Polish source, because no Polish source in our registry covers this topic. When this applies to only some of the claims, the foreign ones carry the same label next to their source.
Sources
- NHS (nhs.uk, Anglia)License: Open Government Licence v3.0. Source: NHS (nhs.uk, Anglia). Content summarized and translated by the editors; changed relative to the original. Contains public sector information licensed under the Open Government Licence v3.0. The summary is ours and is not attributed to the NHS.
- Portal Pacjenta (pacjent.gov.pl)License: CC BY 3.0 PL. Source: Portal Pacjenta (pacjent.gov.pl). Content summarized and translated by the editors; changed relative to the original.