For a long time, people thought that IQ tests were a good way to measure how smart someone was. Psychologists, especially in the US, are now paying more attention to personality traits and everyday behaviours that show a sharp mind without saying anything. One of these habits tends to shock friends, family, and coworkers.
From IQ tests to bad behaviour in people
Standardised intelligence tests were made to guess how well someone would do in school and later on the job. They test your memory, logical thinking, language skills, and ability to think in three dimensions. They don’t check how someone reacts when a project fails, a child screams, or a boss sends yet another unreasonable email.
That gap made psychologists like Harvard professor Howard Gardner suggest “multiple intelligences,” which include linguistic, logical-mathematical, musical, interpersonal, intrapersonal, and other types. A long-running American study that followed hundreds of parents and children has backed up this larger view.
Researchers who followed families for more than twenty years found that the smartest people have three surprising personality traits that are easy to see outside of school and work.
The study, which was based on Gardner’s work and later expanded by teams at Stanford, looked at more than just test scores. It also looked at how people deal with emotions, failure, and social stress. The results go against a long-held belief that smart people are polite, do what they’re told, and don’t get emotionally involved.
The first sign is a calm mastery of anger.
Emma Seppälä and her team at Stanford found that people who were very smart were better at controlling their emotions. They were still angry or annoyed. They just reacted in a different way.
Instead of slamming doors, sulking, or lashing out, they usually said what they were feeling and put it into words. That one simple habit—saying “I’m really annoyed by this delay” instead of being angry—helped them calm down, talk things over, and make better choices.
Putting your anger into words is like opening a pressure valve: it lowers the intensity of your emotions and gives your mind more room to think about how to solve problems.
This ability is very similar to emotional intelligence. People who can notice, name, and talk about their own feelings often deal with conflict in a less dramatic way. They are more likely to stop and think about how they feel, look at things from other people’s points of view, and change their plans.
That being said, people can get this trait wrong. When things get tough, the emotionally intelligent coworker who stays calm may be called “not caring enough.” Their brain is actually working hard to keep the temperature down so they can deal with the real issue.
How emotional regulation works in real life
Instead of blowing up, a parent says to a teenager, “I’m worried and a little mad about your late texts.”
Instead of blaming the team, the manager says, “This delay is frustrating; let’s figure out what we can control.”
A partner says, “That joke hurt me,” which starts a conversation instead of a cold war.
These are not big things. They are little decisions that happen over and over again that keep relationships safe and make it easier to think about complicated things.
Second signal: a completely different way of thinking about mistakes
The same long-term study found another pattern: people with high abilities see mistakes as opportunities to learn, not as judgements of their worth. A failed launch or exam is just data, not a personal failure.
For many smart people, making a mistake is less embarrassing than hiring an unpaid consultant who gives them painful but useful feedback.
This is what psychologists call “self-compassion”: being aware of your mistakes without hating yourself. People who think this way are still disappointed. They don’t let the setback define who they are. That way of thinking helps you be strong, which means you can change and bounce back instead of freezing or running away.
On the other hand, people with lower cognitive scores were more likely to blame others, deny responsibility, or hold on to strict stories about “bad luck.” That reaction may help the ego in the short term, but it makes learning and solving problems take longer.
Stanford teams say that this flexible way of dealing with mistakes might be more important for long-term success than how fast the computer processes data. A brain that works quickly but panics when it stumbles stays underused.
Third signal: swearing a lot and using it like a tool
The research’s most socially explosive finding is about language. A lot of the smartest people swore more than they should have. Not all the time and not at random, but enough to upset people who think of themselves as polite geniuses.
When you swear on purpose, it can help you think better by acting as an emotional shock absorber and a confidence booster.
Other research supports this. Studies at US universities have shown that people who are allowed to swear while doing painful tasks say they feel less pain. In the workplace, strong language can make people feel more real and united, as long as it isn’t aimed at a person or group.
For some very smart people, a well-placed curse word is just more effective. It combines frustration, humour, and emphasis into one short word. It can also show the line between “this is a little annoying” and “this is serious; we need to do something.”
When swearing works and when it doesn’t
Helps when you’re frustrated with a team you trust and want to say, “I’m in this with you.”
Helps when you need to calm down in private so you don’t lash out at someone who is weak.
When it attacks someone’s identity, it becomes verbal aggression.
When used all the time, it backfires, losing its emotional impact and sounding lazy or hostile.
The researchers point out that the good effect goes away if swearing becomes background noise. If you use it every other sentence, it stops controlling your emotions and starts to break down trust. It can work like a pressure release without hurting relationships if you don’t use it too much.
Why these traits often surprise family, friends, and coworkers
People still think that smart people are cold, overly rational, and polite. So, someone who can come up with complicated ideas quickly but isn’t afraid to use bad language can make people confused or angry.
Parents might say to their child, “Speak intelligently,” which means “Don’t swear.” Office etiquette guides still say that using strong language shows a lack of control, not subtle regulation. That goes against what behavioural data is starting to show.
The shock often comes from an old script that says “smart” means “calm” and “clean-mouthed.” Real life intelligence is more complicated and emotionally open.
The fight is also happening at home. It can be hard to read a partner who calmly calls out their anger, admits to failing, and then swears during a stressful DIY project. Are they handling it well or going crazy? The study shows that they might be doing both: talking about their feelings and keeping their behaviour in check.
How to put these ideas into practice in daily life
You don’t need a study from Stanford to change your habits. Researchers saw the same mechanisms at work in high-ability participants when they made simple changes.
Useful ways to teach “smart” behaviours
Before you answer that email, say out loud how you’re feeling: “I’m really on edge right now.”
After a setback, do a failure debrief. Write down three things you learned and one specific change you will make next time.
Set a private swearing zone where you can use strong language without kids or clients around.
Instead of saying “I’m useless,” say “What did I miss here?”
Each of these steps helps you feel less overwhelmed and frees up your mind. That extra capacity can then be used for reasoning, creativity, and long-term planning, which are the skills IQ tests were made to measure.
How intelligent people process failure
| Situation | Typical reaction of highly intelligent person |
|---|---|
| Project collapses at work | Asks what assumptions were wrong, notes lessons, proposes adjustments |
| Exam result is poor | Reviews preparation strategy, changes revision method, asks for feedback |
| Argument hurts a friend | Accepts their part, apologises, reflects on communication patterns |
Cultural differences, risks, and limits
There are lines that are clear. In some workplaces or cultures, swearing at work is always a risk, no matter what you meant to say. Power dynamics are important: a senior executive’s “casual” curse word can make junior staff feel scared.
Emotional control can only go so far. If you never talk about or deal with your feelings, staying calm all the time can turn into suppression. The goal is not to become a robot, but to keep your feelings in check so you can still think.
Psychologists also say that treating these behaviours as a sign of superiority is not a good idea. A lot of smart, caring people hardly ever curse. Some people still have trouble with frustration, but they are great at analysing or being creative. Intelligence is still a complicated mix of traits, not just one habit that gives it away.
Important words and a simple thought experiment
There are two ideas behind a lot of this research. Being able to control which emotions you feel, when you feel them, and how you show them is called emotional regulation. Being kind to yourself means being as patient and fair with yourself as you would be with a close friend.
A quick example shows how they work together. Imagine two engineers whose product update doesn’t work.
Engineer A yells at coworkers, blames marketing, and spends the night going over the disaster.
Engineer B mutters a sharp curse word, goes for a walk, admits they got the timeline wrong, and makes a list of fixes.
On paper, both are smart. The study indicates that Engineer B is more apt to translate that intelligence into sustained advancement. The little, shocking burst of language doesn’t mean you’re stupid. It could be what keeps it going.
