Aggression in children can take many forms: Angry tantrums; hitting, kicking, or biting; hot-headed outbursts that destroy property; cool-headed bullying; verbal attacks; attempts to control others through threats or violence.

But, what sets children off?

In some cases, kids lash out because they’re frustrated by a problem that’s too big for them. They haven’t yet learned how to control their impulses or work out conflicts in socially acceptable ways. In other cases, kids may be wrestling with special difficulties — like stressful life events, emotional regulation problems, attention deficits, autistic symptoms, or hyperactivity. Yet in all cases — even where children have been diagnosed with serious conduct disorders — adults can have a powerful influence.

Aggression doesn’t happen because we’re programmed to respond to the world with hostility. We all have the capacity to behave aggressively. Whether or not we do it depends on how we perceive the world.
Aggressive tendencies are shaped by environmental conditions — the pressures, threats, opportunities, and consequences that children experience. By tweaking these conditions, we can improve behavior and change the course of development.

That doesn’t mean it’s your fault if your child is acting out.

Genetic factors put some kids at higher risk for trouble. So does early life stress.

Large-scale twin studies confirm that genetic factors put some of us at higher risk for aggressive behavior (Luningham et al, 2020). And children are more likely to develop aggressive behavior problems if they are exposed to lots of early life stress (Palumbo et al, 2018).

Aggression in children is also influenced by environmental forces outside the home. Peers, teachers, neighborhoods, media messages, ideologies, and cultural factors all play a role. And these environmental effects will vary depending on your child’s genes, prenatal factors, and early life exposure to stress.

Studies indicate that some kids don’t experience a normal spike of the stress hormone cortisol in response to stressful situations. Others might experience a surge but take an unusually long time to recover. Both types of children are at higher risk of developing aggressive behavior problems (Schoorl et al, 2017). But whatever factors put a child at risk, there is nothing inevitable about the outcome. When caregivers get the help they need, they can have an important impact.

Randomized, controlled studies show that aggressive kids change trajectory when parents get practical training and moral support (Furlong et al, 2013; Piquero et al, 2009; Shellby and Shaw, 2015; Waller et al, 2013; Maaskant et al, 2017; Scrool et al, 2017). The interventions work, in part, because parents learn specific tactics for handling aggression. But they also work because parents learn to change their outlook.

Struggling with a child’s behavior problems is stressful and demoralizing. It saps your resilience, your sense of optimism, competence, and goodwill. It can redefine the parent-child relationship in a destructive way, and prompt you to think about your child in ways that undermine your ability to cope. And counterproductive thoughts fuel the conflict and make behavior problems worse. Replace these toxic mental habits with positive, constructive, problem-solving thoughts, and you can stop bad behavior before it erupts (Dittman et al, 2016; Furlong et al, 2013; Shellby and Shaw, 2014).

Aggression in children can be a symptom of many different underlying problems. It’s a very polymorphic thing, a commonality for any number of different psychiatric conditions, medical problems, and life circumstances. At the very essence of treating aggression is first to find out what’s driving it. No behavior occurs for no reason. There is always an underlying unmet need that’s driving the behavior.

You can break down the causes of aggression into several groups.

Mood disorders. First, are there mood issues? Kids who are bipolar, in their manic stages, very frequently become aggressive. They lose self-control, they become impulsive. On the other end of the spectrum, when they become depressed, although aggression is less common, they can become irritable, and sometimes that irritability and cantankerousness cause kids to lash out.

Psychosis. The psychotic illnesses may also manifest with aggression. For example, kids with schizophrenia are often responding to internal stimuli that can become disturbing. Sometimes kids with schizophrenia become mistrustful or suspicious—or full-blown paranoid—and they wind up striking out because of their own fear.

Frustration. Kids who have problems with cognition (what’s now called intellectual impairment) or communication (including autism) may also manifest with aggression. When children with these conditions become aggressive, they often do so because they have difficulty dealing with their anxiety or frustration and can’t verbalize their feelings as others do. The aggression may also be a form of impulsivity.

Impulsivity. And then there are disruptive behavior disorders. In children with ADHD, the most common of them, impulsivity and poor decision-making can lead to behavior that’s interpreted as aggressive. These children often don’t consider the consequences of their actions, which may come across as callous or malicious when they’re really just not thinking.

Conduct Disorder. With conduct disorder, aggressiveness is part of the matrix of the illness, a large component of what that is. Unlike the child who just isn’t considering the consequences of his actions, kids with CD are intentionally malicious, and the treatment and prognosis are quite different.

Injury. Sometimes there are organic reasons for aggressive outbursts when a child has frontal lobe damage or certain types of epilepsy. In these cases, there may be no comprehensible reason for the aggressive episode, and the episode could have an explosive component.

Trauma. Finally, there are times when aggression in children or teenagers is provoked by stressors in their situation and does not represent an underlying emotional illness. But it is important to understand that this is fairly rare, and when aggression begins to happen on a more frequent basis, it could represent a brewing emotional problem.

Again, aggression doesn’t happen because we’re programmed to respond to the world with hostility. We all have the capacity to behave aggressively. By tweaking these conditions, we can improve behavior and change the course of development. A child psychologist can help to determine the causes of aggression and help to improve behavior and change the course of development.