Aggression does not disappear in civilized systems; it changes direction and learns better disguises.
The claim that humans might actually use outward aggression more than self-aggression because self-aggression has a smaller behavioral range and is less effective. There is partial truth there.
Self-aggression is actually very widespread, but it is often hidden inside socially acceptable forms. It is not limited to self-hatred, bodily harm, or suicide. It includes chronic self-undermining, remaining in degrading roles, refusing opportunities that would increase autonomy, internalizing contempt from authority figures, or the most often reproducing abusive relational patterns. These behaviors are not recognized as aggression because they look like weakness or inertia. But structurally they are aggression redirected inward.
Why does this happen frequently in people who grew up with aggression from parents or environment? Because early environments calibrate what the nervous system expects as normal relational dynamics. If hostility, humiliation, or domination were common, the organism may interpret them as baseline conditions of social life. Later, when similar dynamics appear, the system does not classify them as abnormal threats; it treats them as familiar terrain.
There is another piece that complicates the above conclusion that the self-image system. Humans defend self-image because identity stability helps coordinate behavior. But the defense of self-image can produce both outward aggression and self-aggression depending on which preserves the internal narrative. Sometimes attacking others protects identity. Sometimes attacking oneself does for example, accepting blame preserves a sense of moral coherence or belonging.
So the real mechanism is not simply “aggression vs self-aggression.” It is where the system can discharge dominance pressure without collapsing its position in the surrounding environment. If outward attack risks punishment, aggression turns inward. If inward attack threatens identity too strongly, aggression turns outward. Most people oscillate between both.
Societies create strong prohibitions against suicide not because humans suddenly become rational or gentle, but because large-scale self-destruction destabilizes social systems. The taboo acts as a containment mechanism. It reduces the probability of certain outcomes that would ripple through families, institutions, and economies. Simply, the slaves do not commit suicides leaving unpaid bredits. But what people present is here not aggression. It is rather energy seeking a channel under constraint. When constructive expansion is blocked and comparison remains active, destructive shortcuts become attractive toward others or toward oneself.
The uncomfortable observation is that many social structures quietly rely on this redirection. Systems remain stable partly because individuals absorb aggression internally rather than expressing it externally.