Physical aggression — hitting, biting, pushing, snatching — is one of the most common behavioural challenges in daycare settings. Parents whose children are on either end of aggressive incidents often feel alarm or guilt. Understanding the developmental context helps calibrate these responses.
Healthbooq supports families in understanding child behaviour and development.
Why Young Children Are Aggressive in Groups
Immature impulse control. The prefrontal cortex — the brain region responsible for inhibiting impulses — is the last part of the brain to mature, not reaching full development until the mid-20s. In toddlers, impulse control is minimal. When a child wants a toy someone else has, the impulse to grab or hit fires before any regulatory process can intercept it.
Limited language. Physical action is the primary communication mode before language is established. A toddler who wants a toy, wants the peer to move, or is frustrated by what someone is doing has no verbal tools for negotiation. Physical action is the available instrument.
Frustration in a constrained environment. Group settings involve sharing, waiting, and accepting limits — all of which are genuinely difficult for young children. Repeated frustration without sufficient language to resolve it leads to physical expression.
Sensory overwhelm. Some children become physically aggressive when they are over-stimulated — noise, proximity, unpredictability combine to overwhelm their regulatory capacity and they act out physically.
The Age-Related Peak
Research on child aggression (including longitudinal work by Richard Tremblay) shows that physical aggression peaks in frequency around 18 months to 3 years and then declines naturally as language and self-regulation develop. Most children who are physically aggressive at 2 are not aggressive by 4.
This does not mean the behaviour should be ignored in the setting — carers should consistently respond to protect other children and teach the child alternative strategies. But it does mean the prognosis is generally good without intensive intervention.
Different Forms at Different Ages
- Under 18 months: biting is the most common form. It often reflects sensory seeking, teething, or extreme excitement rather than deliberate aggression.
- 18 months–3 years: hitting, pushing, snatching are most common. Motivated by frustration, possession conflict, and impulse.
- 3–4 years: physical aggression typically reduces as language develops; relational aggression (exclusion, verbal rejection) may begin to emerge.
What Supports Reduction Over Time
The most effective supports are language development (giving children verbal tools for conflict) and emotional coaching (helping children identify and name what they feel). Direct punishment of aggressive acts without these alternatives tends to produce suppression rather than genuine development of self-regulation.
Key Takeaways
Aggressive behaviour in young children — hitting, biting, pushing, snatching — is extremely common in group settings and is primarily a developmental issue rather than a character or parenting problem. Young children have immature impulse control and limited language for managing frustration. The peak period for physical aggression in children is 18 months to 3 years. Most children grow out of it as language and self-regulation develop.
