Emotional maturity has the ring of a vibe, the kind of thing people claim to have and struggle to define. It turns out to be more measurable than that. Psychologists have tracked how personality actually shifts across a life, and the pattern is consistent enough to have a name. The interesting part, for anyone wondering what growing up emotionally looks like, is that it shows up less in what people start feeling and more in what they stop doing with their feelings.
The broad shape comes from a large body of longitudinal research.
The trend has a name
In a 2006 meta-analysis in Psychological Bulletin, the psychologist Brent Roberts and colleagues pooled 92 longitudinal samples to see how personality traits move over time. The pattern they found is now called the maturity principle. On average, and especially between the ages of 20 and 40, people become more emotionally stable, more conscientious, and more socially confident. In plain terms, they grow steadier and less easily thrown.
Two cautions belong with that finding. It is an average, not a destiny: some people change little, and a few move the other way. And it describes a gradual drift, not a switch that flips at some birthday. But the direction is real and well replicated. Most people do, slowly, calm down.
What the trait language does not quite capture is the texture of it, the specific behaviours that fall away. For that, a different and older framework is more useful.
What actually gets dropped
The psychiatrist George Vaillant spent his career studying how people handle stress and threat, and organised these coping styles into a rough hierarchy, from immature to mature. Emotional growing-up, in his account, is largely a climb up that ladder.
Near the bottom sit the moves most people would recognise as childish once they are named. Acting out, letting a feeling discharge straight into behaviour rather than being felt. Projection, the trick of relocating an uncomfortable feeling into someone else, so that the problem is reliably the other person. Passive aggression, and the flat denial that anything is wrong at all. These are not signs of a bad character. They are simply the earliest tools, and much of maturing is quietly retiring them.
Higher up sit the responses that look, from outside, like composure. Humour that takes the sting out of a situation without hiding it. The ability to anticipate a hard thing and prepare for it rather than be ambushed. Sublimation, channelling a strong feeling into work or effort. And what Vaillant called suppression, the deliberate choice to set a reaction aside for now, which is worth distinguishing carefully from simply burying it.
Put practically, the things people tend to stop doing are recognisable: blaming everyone else by default, treating every feeling as an emergency that must be acted on immediately, needing to win the argument in the moment, sulking instead of saying the thing, and reading disagreement as an attack. None of these vanish completely. They just stop being the automatic first move.
A caution against mistaking reserve for maturity
There is a trap worth flagging, and it is one this part of the world is prone to. Emotional maturity is easy to confuse with emotional restraint, the stoic non-reaction that reads as unbothered. In Scandinavia in particular, a cultural preference for keeping the temperature low can look like the finished article.
The research does not support the equation. Vaillant’s mature suppression, deciding not to react right now, is a different thing from repressing a feeling out of awareness or performing calm while quietly seething. Simply not showing anything is not the same as having processed it, and a large literature on emotion regulation finds that bottling feelings up, as opposed to reframing them, carries its own costs. Reserve can be maturity. It can also be avoidance wearing maturity’s coat. The difference is whether the feeling was handled or merely hidden.
What this is and is not
A few limits are worth keeping. The maturity principle is a population average, not a verdict on any individual, and Vaillant’s hierarchy is a clinical framework, illuminating rather than exact. “Maturity” also carries a value judgement that is easy to weaponise, and none of this is meant as a ruler to measure other people against, least of all in an argument.
Read descriptively, though, it is oddly reassuring. Growing up emotionally is not mainly about acquiring some richer inner life. It is about the slow subtraction of a few reflexes: the blame, the outburst, the need to be right immediately, the treatment of every feeling as a fact that demands action. What is left when those go is not coldness. It is room. The feelings are still there; they simply stop running the place.