It appears that people who think they know it all - or at least, a lot - may be on to something.

A study in the US has found people who rate their own intelligence highly tend to get higher marks.

The finding was a surprise to researchers at Baylor University and the University of Mary Hardin-Baylor, who had theorised that “intellectual humility” - having an accurate or moderate view of one's intelligence and being open to criticism and ideas - would correlate with grades.

It turns out the research did not know everything.

But being full of oneself when it came to rating intellectual arrogance - an exaggerated view of intellectual ability and knowledge - instead generally predicted academic achievement, especially on individual course work, according to the study.

“One possibility is that people who view themselves as intellectually arrogant know what they know and that translates to increases in academic performance,” said researcher Wade Rowatt, a professor of psychology and neuroscience at Baylor.

In the study, 103 undergraduate students worked for a full semester in groups of four to six members in upper-level psychology courses.

They did varied tasks, both individually and together. They then took a series of tests - first individually, then with fellow group members, who gave feedback on each member's work.

They completed questionnaires to measure ‘intellectual humility’, based on such traits as ‘open to criticism’ and ‘knows what he/she is not good at’. They also measured ‘intellectual arrogance’, based on such traits as ‘is close-minded’ and ‘believes own ideas superior to others' ideas’.

Despite ‘intellectual arrogance’ being linked with higher actual test scores, it did not translate well in a group setting.

The study instead found that with group projects, other team members gave better evaluations to those they viewed as humble.

“If people are forming opinions about extraversion and someone talks a lot, it's easy to draw consensus about that person,” said lead author Benjamin Meagher.

“But it's more challenging for groups to recognize what behaviour reveals another person's humility, as opposed to simply being shy or unsure.

“What I think is important about intellectual humility is its necessity for not only science, but for just learning generally - and that applies to the classroom, a work setting, wherever,” Meagher said.

“Learning something new requires first acknowledging your own ignorance and being willing to make your ignorance known to others.

“People clearly differ in terms of their willingness to do something like that, but that willingness to learn, change one's mind and value the opinion of others is really needed if people and groups are going to develop and grow.”

The research – ‘Contrasting self-report and consensus ratings of intellectual humility and arrogance’ - is published in the Journal of Research in Personality.