May 9, 2022 • 1hr 28min

Understanding & Controlling Aggression

Huberman Lab

In this episode, Dr. Andrew Huberman discusses the neurobiology, psychology, and tools for understanding and controlling aggression. He explains that there are different types of aggression, including reactive, proactive, and indirect aggression. Huberman emphasizes that context is crucial when discussing aggression, as it can be adaptive in some situations and maladaptive in others. The episode covers the neural circuits involved in aggressive behavior, the role of hormones like testosterone and estrogen, and how environmental factors can influence aggression. Huberman also discusses various tools and strategies for managing aggressive tendencies, including supplements, lifestyle changes, and improving self-regulation.

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Key Takeaways

Aggression is controlled by specific neural circuits, particularly in the ventromedial hypothalamus (VMH), not just individual brain areas
Estrogen, not testosterone, directly triggers aggressive behavior by activating estrogen receptor neurons in the VMH
Testosterone indirectly contributes to aggression by being converted to estrogen in the brain and by increasing competitiveness/effort
Cortisol and serotonin levels modulate the likelihood of aggressive behavior - high cortisol and low serotonin increase aggression
Environmental factors like day length, sunlight exposure, and competitive environments can influence aggressive tendencies
Caffeine can increase impulsivity and aggression, especially when combined with alcohol
Supplements like omega-3s, ashwagandha, and acetyl-L-carnitine may help reduce aggressive behavior in some cases
Self-regulation is key for controlling aggressive impulses. Tools to improve self-regulation can help manage aggression.

Introduction

In this episode, Dr. Andrew Huberman discusses the neurobiology, psychology, and tools for understanding and controlling aggression. He explains that there are different types of aggression, including reactive, proactive, and indirect aggression. Huberman emphasizes that context is crucial when discussing aggression, as it can be adaptive in some situations and maladaptive in others.

The episode covers the neural circuits involved in aggressive behavior, the role of hormones like testosterone and estrogen, and how environmental factors can influence aggression. Huberman also discusses various tools and strategies for managing aggressive tendencies, including supplements, lifestyle changes, and improving self-regulation.

Topics Discussed

Neural Circuits for Aggression and the "Hydraulic Pressure Model" (0:08:29)

Huberman introduces the concept of neural circuits controlling aggression, referencing the work of Konrad Lorenz and his "hydraulic pressure model" of behavior. This model suggests that internal and external factors build up pressure towards aggressive behavior.

Aggression is controlled by neural circuits, not just individual brain areas
The "hydraulic pressure model" helps explain how multiple factors contribute to aggressive behavior
Aggression is a process with a beginning, middle, and end, not just an on/off switch

Brain Regions Controlling Aggression: Ventromedial Hypothalamus (VMH) (0:15:50)

Huberman discusses the key brain region involved in aggression: the ventromedial hypothalamus (VMH). He describes experiments by Walter Hess and more recent work by David Anderson's lab at Caltech.

The VMH contains about 3000 neurons that can generate aggressive behavior
Stimulation of the VMH can trigger immediate aggressive responses in animals
"When you see somebody who's in the act of rage or an act of verbal aggression or in an act of defensive aggression, protecting their family or loved ones or country, et cetera, almost certainly those neurons are engaged in that behavior." - Dr. Andrew Huberman

Estrogen Receptors & Aggression (0:23:36)

Huberman explains the surprising role of estrogen in triggering aggressive behavior, contrary to popular belief about testosterone's role.

Estrogen receptor-containing neurons in the VMH are responsible for generating aggressive behavior
Testosterone is converted to estrogen in the brain through aromatization
It is the estrogen, not testosterone, that directly activates aggression circuits

Testosterone & Competitiveness/Estrogen & Aggression (0:35:56)

Huberman clarifies the roles of testosterone and estrogen in aggressive and competitive behaviors.

Testosterone increases competitiveness and willingness to lean into effort, not aggression directly
Testosterone can be converted to estrogen in the brain, which then triggers aggression
Blocking the conversion of testosterone to estrogen reduces aggression, even with high testosterone levels

Sunlight, Melatonin & Aggression (0:43:00)

Huberman discusses how environmental factors like day length and sunlight exposure can influence aggressive tendencies.

Long days (more sunlight) tend to reduce aggressive tendencies
Short days can increase the likelihood of aggression due to hormonal changes
Melatonin, dopamine, and stress hormones are affected by day length and can influence aggression

Cortisol, Serotonin & Aggressive Behaviors (0:45:46)

Huberman explains how stress hormones and neurotransmitters can modulate aggressive tendencies.

High cortisol levels increase the likelihood of aggressive behavior
Low serotonin levels are associated with increased aggression
The balance of cortisol and serotonin contributes to the "hydraulic pressure" towards aggression

Tools: Omega-3 Supplementation, Sunlight, Sauna & Cortisol Reduction (0:51:56)

Huberman discusses various tools that can help manage aggressive tendencies by modulating cortisol and serotonin levels.

Omega-3 supplementation (1-3g EPA per day) may help improve mood and reduce aggression
Getting sunlight exposure, especially early in the day, can help regulate cortisol levels
Sauna use (20-30 minutes at 80-100°C) can help reduce cortisol levels

Tool: Ashwagandha & Cortisol Reduction (0:55:54)

Huberman mentions ashwagandha as a supplement that can help reduce cortisol levels.

Ashwagandha can be effective for reducing cortisol
Limit use to 2 weeks at a time, with a 2-week break, to avoid potential side effects
Always consult with a healthcare provider before adding supplements to your regimen

Testosterone, Amygdala, Challenge & Effort (1:05:07)

Huberman explains how testosterone affects the amygdala and influences behavior in challenging situations.

Testosterone activates the cortical medial amygdala, biasing individuals towards action
Testosterone makes effort feel good or increases the threshold for effort to feel bad
This effect can contribute to competitive behaviors, not necessarily aggression

Caffeine, Alcohol & Impulsivity (1:09:27)

Huberman discusses how caffeine and alcohol can affect impulsivity and aggressive behavior.

Caffeine increases autonomic arousal and can lead to increased impulsivity
Alcohol initially increases activity by reducing inhibition, then acts as a sedative
The combination of caffeine and alcohol can be particularly problematic for impulsivity and aggression

Tool: ADHD, Acetyl-L Carnitine & Aggressive Behavior (1:17:18)

Huberman describes a study on the use of acetyl-L-carnitine supplementation for reducing aggressive behavior in children with ADHD.

Acetyl-L-carnitine supplementation (100mg/kg, max 4g/day) showed significant reductions in aggressive behavior
The study demonstrated improvements in attention, reduced delinquency, and overall behavior
Combining supplements like acetyl-L-carnitine with other strategies may help manage aggressive tendencies

Conclusion

Dr. Huberman concludes by emphasizing that managing aggression typically requires a multi-faceted approach, combining various behavioral, nutritional, and supplementation strategies. He stresses the importance of understanding the complex interplay between neural circuits, hormones, and environmental factors in influencing aggressive behavior.

Huberman recommends considering factors such as sunlight exposure, stress levels, diet, and supplementation when trying to manage aggressive tendencies. He also highlights the importance of self-regulation and improving one's ability to control impulsive behaviors.

Finally, Huberman mentions an upcoming episode featuring Dr. David Anderson, an expert on the neurobiology of aggression, which will further explore these topics and their relationship to other emotional states and behaviors.