16 Traits of a Highly Unintelligent Person Backed By Science

People’s actions and decisions can often leave you scratching your head. That might involve their inability to think critically or their tendency to act impulsively, but either way, such traits are scientifically linked to a lack of intelligence. This doesn’t mean they’re bad people or incapable of personal growth, it’s just that these characteristics might reveal gaps in reasoning, knowledge, or adaptability.

So, to show you what we mean, here is a list of traits that are common in highly unintelligent people.

Overconfidence Without Expertise

Photo Credit: imtmphoto/Shutterstock

Some individuals are overly sure of their abilities, even when their skills don’t back them up. Famously, this kind of overconfidence often stems from the Dunning-Kruger effect, a psychological phenomenon where people with low ability overestimate their competence.

For example, someone might loudly claim they’re an expert in a topic, only to struggle when asked basic questions about it. Sadly, this kind of misplaced confidence can make them resistant to feedback or unwilling to learn, which only reinforces their lack of growth.

Poor Emotional Regulation

Photo Credit: Gladskikh Tatiana/Shutterstock

Having an inability to control emotions, particularly anger or frustration, tends to point to struggles with intelligence. In fact, scientific research has linked higher intelligence to better emotional regulation and self-control. Someone might lash out during minor disagreements or find themselves frequently apologizing for losing their temper.

Resistance to Learning New Things

Photo Credit: Pheelings media/Shutterstock

One of the most destructive forms of unintelligent behavior involves shutting down in the face of new knowledge or ideas. This might include refusing to update outdated beliefs, avoiding challenging conversations, or blocking personal growth. Many studies have shown that open-mindedness is strongly correlated with cognitive ability, so keep that in mind!

Frequent Blaming of Others

Photo Credit: ViewStock/Shutterstock

Another famous trait that is linked to low intelligence is the tendency to blame others for personal problems. Instead of reflecting on their role in a situation, these people will instinctively point fingers elsewhere. Essentially, this habit often stems from an inability to process complex problems and take accountability.

Struggling With Abstract Thinking

Photo Credit: antoniodiaz/Shutterstock

It should go without saying that unintelligent people tend to struggle with abstract thinking. That’s because doing so involves analyzing complex concepts, making subtle connections, and thinking beyond the literal.

A classic example of this is people who struggle to interpret metaphors, understand symbolic representations, or grasp nuanced ideas. Unfortunately, a lack of this skill often leads to rigid thinking, where everything is seen in black-and-white terms, leaving little room for creativity or deeper understanding.

Habitual Impulsivity

Photo Credit: Mallika Home Studio/Shutterstock

Believe it or not, the simple act of impulsivity is a clear indicator of unintelligent behavior–especially when it leads to poor decision-making. Acting without thinking, such as by overspending, overeating, or jumping into risky situations, reflects an inability to weigh the consequences.

Lack of Curiosity

Photo Credit: kapinon.stuio/Shutterstock

Unintelligent people often lack curiosity, as well as the previously mentioned resistance to growth and exploration. They’ll stick to what they already know, avoiding new challenges or information. At the end of the day, this reluctance typically stems from fear of failure, which is quite sad.

Overreliance on Gut Instincts

Photo Credit: Jeanette Dietl/Shutterstock

There’s no denying that intuition can be helpful in some situations, but relying solely on it often leads to unintelligent decisions. In such instances, someone might ignore evidence or logical reasoning, preferring to go with their “gut feeling.” This tendency becomes problematic when their instincts are based on incomplete or incorrect information.

Struggling With Problem-Solving

Photo Credit: Max kegfire/Shutterstock

Obviously, a lack of problem-solving skills goes hand in hand with low intelligence. People with limited problem-solving skills often struggle to analyze situations, identify solutions, or adapt to challenges, panicking when faced with unexpected issues rather than breaking the problem into manageable steps.

It’s a sad fact that this inability to think critically typically leads to frustration, reliance on others for guidance, or repeated mistakes. Remember: problem-solving requires creativity, patience, and logical reasoning—all of which are key indicators of intellectual strength.

Overdependence on Routine

Photo Credit: Shutterstock

Sure, routines can be healthy, productive, and comforting, but be careful not to become overdependent on them, as this signals inflexibility and lack of adaptability. Notably, people with lower intelligence often struggle with this as they resist change, preferring to stick with familiar habits even when they’re no longer effective.

Difficulty Understanding Other Perspectives

Photo Credit: -Srdjan Randjelovic/Shutterstock

It’s commonly known these days that struggling to empathize or understand other viewpoints can reflect a lack of social intelligence, which is closely tied to overall intelligence. People with this trait often dismiss opinions that differ from their own or fail to consider the emotions of others.

For example, they might interrupt conversations to assert their ideas without listening to opposing arguments–that’s not good.

Oversimplifying Complex Issues

Photo Credit: Roman Samborskyi/Shutterstock

You’d be surprised at how easy it is for intelligent people to reduce nuanced problems to overly simple explanations. As you can probably imagine, this indicates their lack of a deeper understanding of the topic. They’ll probably jump to conclusions, ignoring details or context, leading not only to misunderstandings but also perpetuating stereotypes and misinformation.

Frequent Use of Logical Fallacies

Photo Credit: fizkes/Shutterstock

Logical fallacies are errors in reasoning that undermine arguments, and their frequent use can suggest cognitive limitations. A classic example is when someone relies on tactics like appealing to emotion, using irrelevant examples, or presenting false dilemmas to “win” debates.

For instance, someone arguing against environmental regulations might dismiss evidence by saying, “You can’t trust scientists—they’re biased.”

Limited Vocabulary

Photo Credit: Prostock-studio/Shutterstock

Even though intelligence isn’t solely measured by how many words someone knows, a limited vocabulary can definitely reflect gaps in education or intellectual curiosity. Those with smaller vocabularies tend to struggle to articulate complex ideas or understand nuanced concepts, resorting to vague language or clichés when explaining their thoughts.

Resistance to Constructive Criticism

Photo Credit: Shutterstock

It’s really quite unfortunate how unintelligent people are often unable to accept feedback. They’ll dismiss criticism outright, becoming defensive or even lashing out when their flaws are pointed out.

The problem with this is that they might reject helpful suggestions at work, seeing them as personal attacks rather than opportunities for improvement.

Focus on Short-Term Gratification

Photo Credit: Mongkolchon Akesin/Shutterstock

Last but not least, prioritizing immediate rewards over long-term goals is one of the most classic signs of unintelligence, as it prioritizes impulsivity over rational thinking. Generally, this trait manifests through behaviors like overspending, neglecting responsibilities, or procrastinating.

Perhaps unsurprisingly, research has actually shown that delayed gratification is always the best choice and is a key indicator of intelligence, as it requires planning, patience, and self-control.

Up Next: