Agreeableness and Intelligence: Are Nice People Smarter?

For decades, the link between personality and intelligence has been a heavily debated topic.

While some believe this relationship to be tenuous, others argue that the two are closely intertwined.

One personality trait commonly associated with intelligence, is that of agreeableness—one of the Big Five Personality Traits.

But how does this measure up in reality? Are nice people actually smarter?

Are Agreeableness and Intelligence Related?

Despite mainstream culture often associating traits of high agreeableness (eg: politeness, 'niceness', sensitivity) with intelligence, research tells a different story. Bar a few exceptions, majority of research suggests there is no relationship between agreeableness and intelligence.

While agreeableness (and personality in general) has previously been considered entirely separate from intelligence, some researchers have challenged this idea.

Part of this is due to the extensive similarities between the two concepts.

For example, both intelligence and personality remain relatively stable throughout our lifetimes. Evidence also suggests that both factors are genetically determined to some extent.

Furthermore, evidence indicates that both are related to many aspects of health.

However, when you look at the evidence for the relationship between the two, it’s mixed, with findings highlighting no relationship in some aspects of intelligence, yet a significant relationship with others.

Agreeableness and Intelligence: A Weak Relationship?

An extensive meta-analysis conducted in the 90s revealed a next-to-nothing correlation between agreeableness and two forms of intelligence:

• General intelligence (broad mental capacity), and;

• Crystallized intelligence (knowledge from prior learning and past experiences)

Similarly, in a 2005 study, it was found that agreeableness had almost no relationship with cognitive ability and problem-solving attributes on the Wonderlic Personnel Test.

Potential Positive Relationships

On the contrary, other evidence suggests that there is a relationship between agreeableness and specific forms of intelligence.

For example, research involving psychometric testing on intelligence, has found a significant positive relationship between agreeableness and emotional intelligence.

Further research has also shown that agreeableness (modesty in particular) was significantly negatively correlated with self-estimated intelligence.

This suggests that highly agreeable people scored themselves lower for self-estimated intelligence even though they didn’t perform any worse on psychometric tests. 

Why Are Agreeable People Perceived as More Intelligent?

Why do many people assume agreeable people are intelligent, even when there’s no hard proof to back up this belief?

Psychologist Jeremy Dean suggests that this could be because people often presume that social and interpersonal skills go hand in hand with intelligence.

In actual fact, evidence suggests that this isn’t the case. In a 2008 study examining the perceived relationship between personality and intelligence, it was found that participants rated intelligent people as more extroverted, emotionally stable, conscientious, and open to experience.

Furthermore, participants believed that intelligent people were untrusting toward others and demonstrated less compliance with rules. This goes directly against two prominent features of agreeability.

But while this is an interesting finding, it is confined to a purely Estonian sample. Therefore, this area requires further research.

Bottom Line

There seems much to be deliberated when it comes to agreeableness and intelligence. Not only is the relationship between the two heavily debated, but the exact definition of intelligence comes under fire too.

The research broadly demonstrates that while some elements of intelligence (general and crystallized) aren’t related to agreeableness, emotional intelligence might well be.

Yet, many still perceive agreeableness to be strongly related to intelligence, despite evidence suggesting otherwise. This may shed light on our inflated perception of the importance of social and interpersonal skills for intelligence.

Further research is necessary to understand the underpinnings of this complex relationship.