Tantrums peak somewhere between about eighteen months and three years, occur in the overwhelming majority of children, and are the single most common source of parental embarrassment.
They're also the predictable output of a specific developmental mismatch.
The mismatch
Several things arrive at different times.
Toddlers develop strong preferences and a sense of themselves as separate agents with their own intentions. That happens early.
Language sufficient to express those intentions arrives later, and lags substantially behind comprehension. A child who understands a great deal may be able to say very little.
The capacity to regulate strong emotion — to tolerate frustration, delay gratification, and modulate a response — depends on prefrontal development that continues for many years.
So you have a person with strong wants, limited means of expressing them, and almost no capacity to manage the resulting frustration. A tantrum is what that combination produces.
Which is why the frequency declines as language develops, and why children with language delays frequently have more of them.
What's happening during one
Research analysing the acoustics and structure of tantrums has found they're not a single state but a sequence, typically with anger-related behaviours early and sadness-related ones later.
That has a practical implication. The anger phase is not receptive to reasoning, comfort or negotiation. Attempts to intervene during it frequently extend it.
The sadness phase is when a child becomes receptive to comfort, and that's when contact helps.
Which suggests waiting through the first phase rather than trying to stop it, and being available for the second.
What doesn't work
Reasoning during the peak. The capacity to process language and consider consequences is not available at that moment. Explanation is for afterwards.
Escalating. Shouting adds arousal to a system already overwhelmed.
Giving in to end it. Understandable in a supermarket, and it teaches that tantrums work, which increases frequency. Intermittent reinforcement is particularly effective at maintaining a behaviour, which means occasionally giving in is worse than consistently giving in or consistently not.
Asking questions. "What's wrong?" requires processing and answering, neither of which is available.
What helps
Staying present and calm. Not necessarily engaging — being nearby and unbothered. Your regulation is what the child eventually borrows.
Ensuring safety and otherwise waiting. Move things they could hurt themselves on. Otherwise, wait it out.
Naming the feeling afterwards. Not during. Afterwards, briefly and simply. This is how emotional vocabulary develops, and vocabulary is what eventually replaces the tantrum.
Reconnecting. A tantrum is frightening for the child too. Contact afterwards matters more than any lesson.
Prevention, which is most of it
The highest-value work happens before the tantrum.
Hunger and tiredness. An enormous proportion of tantrums are attributable to one or both. Tracking when they happen usually reveals a pattern, and the fix is scheduling rather than discipline.
Warning about transitions. Being removed abruptly from something absorbing is a common trigger. A warning gives time to adjust.
Offering constrained choices. Autonomy is a large part of what's being asserted. Two acceptable options satisfy it without opening a negotiation.
Reducing the number of refusals. Saying no constantly to small things means you're negotiating all day. Deciding which things genuinely matter, and letting the rest go, reduces the total conflict considerably.
Not scheduling too much. A tired toddler at the end of a long day of activities is a tantrum waiting for a trigger.
In public
The situation that causes most distress, and the distress is mostly about being observed.
The useful reframe: most people watching either have children or had them, and are not judging. The ones who are judging are wrong and their opinion is worth nothing.
Practically: the same approach works. Move somewhere safer if needed, stay calm, wait. Leaving is a legitimate option and not a defeat.
What makes it worse is changing your response because you're being watched — giving in in public and holding firm at home teaches a child exactly where the leverage is.
When it might be something else
Some patterns warrant a conversation with a professional.
Tantrums that are very frequent, very prolonged, or persist well beyond the typical age range.
Tantrums involving self-injury or injury to others.
Where the child seems unable to recover afterwards.
Alongside other concerns about development, particularly language or social communication.
Or where a parent is finding their own responses frightening. That is a reason to seek support and it is common, and it is considerably better addressed early.
General information only. Concerns about a child's behaviour or development should be discussed with a qualified healthcare professional.
Your own regulation
The part of this that nobody warns you about: a screaming child triggers a genuine stress response in the adult, and staying calm is a physiological effort rather than a matter of attitude.
Which means the advice to remain calm is asking for something that becomes harder the more tired, hungry or overstretched you are — precisely the conditions under which tantrums are most likely.
Practical mitigations are unglamorous. Recognising your own state before entering a situation likely to produce conflict. Having a plan for stepping away briefly where somebody else is present. And forgiving yourself for the times it does not work, since consistency over months matters and individual failures do not undo it.