The connection between serotonin and dominance was discovered by accident. Primatologists noticed that when a male chimpanzee rose in the dominance hierarchy, his behavior changed—he became more confident, more willing to take risks, less fearful. Neurochemists measuring serotonin levels found the explanation: the rising male's serotonin levels were also rising.1
More remarkably, the causation runs both directions. A male given serotonin-enhancing drugs (SSRIs or serotonin agonists) showed increased dominance behavior—he became more willing to challenge rivals, more confident in group settings, more successful in status competition. A male given serotonin-antagonists (drugs blocking serotonin) showed decreased dominance—less willing to compete, more submissive, lower in hierarchy.2
This bidirectional relationship creates a feedback loop: success in dominance competition increases serotonin, which produces the neurochemical basis for continued dominance behavior (confidence, impulse control, willingness to take risks). Failure and loss of status decreases serotonin, producing depressive symptoms, learned helplessness, reduced motivation to compete.3
The implication is unsettling: your subjective experience of confidence, your motivation to compete, your willingness to take social risks—all of these are neurochemically indexed to your current social rank. How you feel is your brain's accurate tracking of where you stand in the status hierarchy.4
Serotonin doesn't directly cause dominance—it produces the neurochemical state that makes dominance-relevant behaviors more likely. The mechanism appears to involve several effects:
Increased Confidence: Elevated serotonin is associated with increased subjective confidence and reduced anxiety about social competition. A person with high serotonin feels capable of handling challenges; a person with low serotonin feels vulnerable.5
Reduced Fear: Serotonin dampens fear responses to social threat. A person with low serotonin experiences greater fear at potential aggression or social rejection; a person with high serotonin is less phased by these threats.6
Improved Impulse Control: Serotonin enhances prefrontal cortex function, improving impulse control and strategic thinking. A person with adequate serotonin can delay immediate gratification for strategic advantage; a person with low serotonin is more impulsive and reactive.7
Motivation to Compete: Serotonin is associated with motivation to pursue dominance—to engage in status competition, to strive for resources and mates. Low serotonin is associated with reduced motivation for dominance-relevant goals.8
The combination of these effects creates a coherent dominance phenotype: high-serotonin individuals are confident, unafraid, strategically controlled, and motivated to compete. Low-serotonin individuals are anxious, fearful, impulsive, and unmotivated for dominance. The neurochemistry produces the psychology.9
Yet serotonin presents a puzzle: it's associated with both dominance/status and with well-being and contentment. Serotonin-enhancing drugs (SSRIs) are used to treat depression. People with high serotonin report feeling better. Yet high status in a competitive environment isn't always associated with happiness.10
The resolution appears to be that serotonin tracks relative status—where you rank compared to others in your reference group—not absolute well-being or actual life satisfaction. A person can have high status (and thus high serotonin) but be miserable due to other factors (lack of meaningful relationships, meaningless work, health problems). Conversely, a person can have low status (low serotonin) but be satisfied if they've adapted their aspirations to their circumstances.11
SSRIs work by raising baseline serotonin independent of status—they chemically produce the contentment state that evolution shaped to accompany high status. This allows depressed people (often experiencing low status or status anxiety) to feel better without requiring them to actually achieve higher status.
The troubling implication: you can chemically produce the feeling of dominance and contentment without any actual change in your status or circumstances. The neurochemistry and the psychology can be decoupled.12