Understanding & Controlling Aggression

The episode opens by saying that aggression is not one thing. Huberman separates reactive aggression, where people act because they feel threatened or are protecting loved ones who are threatened, from proactive aggression, where people "go out of their way to deliberately try and harm others." He adds a third category, indirect aggression, which involves no physical violence, such as shaming people. His central claim is that different biological mechanisms underlie each type. He promises to cover the neural circuits in the brain and body, the hormones, peptides and neurotransmitters involved, and both psychological and biological tools for controlling aggression.

Before getting to the biology, he argues that any discussion of aggression needs context. People spend money, time and energy on aggression and can even get pleasure from it. He previews circuits that reinforce aggressive acts through the release of chemicals that make people feel good. His main example is vicarious aggression: people pay to watch aggressive sports. He says that seeing your team beat another team releases neurochemicals that feel good and "can make you feel more aggressive." At a much larger scale, he points out that governments invest billions, "if not trillions of dollars," so they can engage in aggression through the military if needed.

Context also separates adaptive aggression from pathological aggression. Maternal aggression, such as a mother protecting her children when they are threatened, is presented as broadly approved, "provided the context is right." Unprovoked, proactive violence, by contrast, makes most observers cringe and can even provoke aggression in the people watching. The episode also previews a pathological side: an explosive aggressive disorder that Huberman says is "far more common than perhaps you know," and the role of attention deficit hyperactivity disorder through the link between impulsivity and aggression. He lists verbal, physical, proactive and reactive aggression as topics.

Protecting our young is, after all, one of the primary adaptive drives of our species, and thank goodness it is.

The stated goal for the episode is a fuller understanding of aggression as seen in others and in oneself, including the impulse toward it. He says the tools he will describe "should allow you to modulate and control aggressive tendencies or predispositions to aggressiveness." He presents these as general aims; the tools themselves are not described in this part of the episode.

Huberman gives a broader reason to study aggression: understanding its biology and psychology puts you in a better position to understand how all emotional states arise. To show this, he takes on a claim he attributes to pop psychology rather than formal academic psychology: that aggression is just amplified sadness. He says the underlying biology and the peer-reviewed literature contradict this. There are distinct brain circuits for aggression and for grief and mourning, and he calls them "nonoverlapping."

He qualifies the point carefully. Separate circuits do not mean a person cannot be sad and aggressive, or grieving and aggressive, at once. What is wrong is treating the two as the same thing. He makes a similar distinction between irritability and aggression. He argues that drawing these lines makes it easier to apply tools that reduce, eliminate or modulate aggression. He also says that in some cases modulating or even amplifying aggression can be adaptive.

the idea that sadness and aggression are one and the same thing is simply not true.

Huberman dates the formal study of aggression to the beginning of the last century and links it closely to Konrad Lorenz. Lorenz studied imprinting and fixed action patterns. He is best known in scientific circles for getting geese to treat him as their parent by swimming in front of goslings, which then imprinted on him; he even lived with them. Huberman says the Nobel-recognized insight was that a single stimulus could evoke a whole category of behaviors across many contexts. This pointed to neural circuits, meaning "collections of brain areas that work together," rather than single brain areas, as what drives patterns of behavior.

From this he draws the episode's first principle. Aggression is the activation of neural circuits that play out in sequence, "like keys on a piano." Because it unfolds in sequence, aggression is better seen as a process than as an event. He says this framing matters in practice: it suggests aggression can be halted, prevented before it starts, or even prolonged "if that's what's needed."

It has a beginning, a middle, and an end. It's a process. It's not an event.

He also notes a limitation of Lorenz's work: Lorenz had no real knowledge of neural circuits and did not try to define them. Lorenz did, however, suggest a concept of "pressure," almost hydraulic, where many factors add up. These include hormones, neurotransmitter states and a person's history, such as their childhood. Huberman uses the image of fluid in a container being pushed until it is ready to explode. Low pressure, by contrast, keeps a person nonreactive or even passive or submissive. He says this is "exactly the way that system works." No single brain area flips an aggression switch, although he previews one structure that generally houses the propensity for and output of aggression. He also suggests people can learn to notice the buildup, or "veering," toward verbal or physical aggression in themselves and others.

The first experiments to locate brain areas behind aggression are credited to Walter Hess, who worked on cats. Huberman acknowledges that many listeners will find this uncomfortable. He explains that few labs use cats today. Fruit flies are used for genetics, and laboratory mice are favored because genes can be knocked out or knocked in, which cannot easily be done in humans or nonhuman primates. In Hess's era, most labs used cats or rats.

Hess lowered stimulating electrodes into the brains of awake cats. Huberman notes that the brain has no pain sensors and that this approach is common in human neurosurgery. Hess was searching on purpose for regions that could produce whole categories of behavior, in the spirit of Lorenz's fixed action patterns. Stimulating one site turned a calm, purring cat into a full rage: arched back, hissing, raised hair (piloerection), drooling and possibly spitting. The cat attacked people and even inanimate objects. When the stimulation stopped, the cat went back to being calm within seconds.