Toddlers hit, push, scratch, and throw things. This is developmentally normal between ages 18 months and 3 years because the prefrontal cortex — the part of the brain responsible for impulse control — is nowhere near mature.
Aggression in toddlers is almost always an expression of an unmet need or overwhelming emotion. They are not being 'bad.' They are expressing something they don't yet have the language or self-regulation to communicate any other way.
The most important response is to remain calm. Children escalate in response to adult escalation. A steady, low voice — 'We use gentle hands. Hitting hurts.' — delivered at eye level is more effective than raised voices or lengthy consequences.
Follow up by helping the child name the emotion: 'You wanted the toy and felt angry. That feeling is okay. Hitting is not okay.' This validates the emotion while maintaining the limit.
For chronic hitting, track when and where it occurs. Patterns reveal triggers — often transitions, overstimulation, or hunger. Addressing the underlying cause reduces the behaviour more reliably than any consequence.
Praise gentle behaviour explicitly and frequently. 'That was so gentle! You touched your friend's shoulder so nicely.' Positive reinforcement of the target behaviour works faster than punishment of the problem behaviour.