A recent study published in the Journal of Intelligence provides evidence that men and women tend to possess different relative cognitive strengths, which may help explain why women remain underrepresented in certain scientific and technical fields. The research suggests that when comparing an individual’s skills against their own personal average, women generally show a relative strength in reading, while men show a relative strength in math. These patterns remain consistent across different countries and age groups, offering a new way to understand career choices.

Scientists Marco Balducci and Waseem Haider conducted the study to explore why the gender gap persists in science, technology, engineering, and mathematics (STEM) careers. Past research on cognitive abilities has typically focused on average test scores, which calculate how well men or women perform compared to each other.

These average differences tend to be very small and fail to explain why large disparities exist in technical professions. Because of this, the researchers wanted to look at a different metric called intraindividual strengths.

Intraindividual strengths measure a person’s abilities compared to their own overall performance, rather than comparing them to the general population. For example, a person might be good at both math and reading, but if their math score is higher than their personal average across all subjects, math is their primary intraindividual strength.

This concept is grounded in expectancy-value theory, a psychological framework suggesting that people choose careers based on what they expect to be best at. According to this idea, a student whose personal best subject is math will likely pursue a technical field, while someone whose personal best is reading might choose an interpersonal profession.

“In my previous research, I analyzed sex differences in intraindividual strengths in high school students, finding very interesting patterns. Overall, girls had an intraindividual strengths in reading while boys had strengths in mathematics or science. However, it remained unclear whether the findings were limited to this specific age group or if they persisted across the lifespan,” explained Balducci, a senior researcher at the University of Turku.

For their new study, the scientists analyzed data from the Programme for the International Assessment of Adult Competencies. This large international survey evaluates the cognitive and workplace skills of adults in everyday situations.

The researchers used a final sample of exactly 157,189 individuals from 30 different countries. They divided these participants into five specific age groups: 16 to 24, 25 to 34, 35 to 44, 45 to 54, and 55 and older.

The survey measured skills in three main areas. Literacy evaluated text interpretation and comprehension, while numeracy assessed the capacity to interpret and use mathematical information. Finally, problem-solving measured the ability to use digital tools to perform practical tasks.

The scientists first calculated the average scores for men and women across these three domains. They then calculated the intraindividual strengths by finding each person’s overall average score across all three tests. They subtracted this personal baseline from each specific subject score to see which domain stood out as a relative advantage.

When looking at the standard average scores, the researchers found almost no differences between men and women in literacy and problem-solving. Men performed slightly better in numeracy on average, but the difference was very small.

However, when looking at intraindividual strengths, a completely different pattern emerged. Women consistently demonstrated an intraindividual strength in literacy, while men demonstrated a strength in numeracy. These differences in personal strengths were about twice as large as the differences found in standard average scores. They were also remarkably consistent across all 30 countries analyzed in the dataset.

“We had anticipated the general direction of the findings based on previous research, but the results were still striking,” Balducci told PsyPost. “The disparity between sex differences in mean scores and those in intraindividual strengths was even more pronounced than in our previous analyses.”

The researchers also discovered that these patterns did not change as people grew older. From young adulthood to the age of 55 and beyond, women consistently maintained their relative advantage in literacy, and men maintained theirs in numeracy.

There were no significant differences between men and women when it came to problem-solving as a personal strength. The researchers noted a strong connection at the country level, finding that larger relative literacy strengths in women matched larger relative numeracy strengths in men.

“Sex differences are significantly more pronounced when measured as intraindividual strengths rather than using traditional mean scores,” Balducci summarized. “While differences in mean scores tend to be smaller and highly variable, intraindividual strengths are generally two to three times larger and remarkably consistent across both countries and age groups.”

“In practice, our study reinforces the argument that we should also explore sex differences through the lens of intraindividual strengths rather than limiting analysis to traditional mean scores. Shifting to this perspective could have profound implications for understanding modern phenomena, such as the persistent underrepresentation of women in STEM fields.”

While these patterns provide evidence for a potential factor behind the gender gap in technical fields, the researchers caution against certain misinterpretations. The most common mistake is assuming that group-level trends apply to every single individual.

Although women tend to have personal strengths in literacy at the population level, many individual women possess strong personal strengths in math. The scientists warn against using these findings to stereotype individual abilities or career potential.

“I would urge readers to always remain mindful of the specific level of analysis and avoid attributing group-level trends to individuals,” Balducci said.

The study also comes with limitations related to how the skills were measured. The literacy assessment only evaluated reading comprehension and did not include a writing component, which might involve different cognitive processes. Because the test was relatively low stakes, participants might not have put in their maximum effort, which could influence the results.

The researchers plan to expand on this line of research. “Building on the results of this and other studies, I intend to extend the concept of intraindividual strengths to broader cognitive domains,” Balducci said. “This would help determine whether the patterns we found are a widespread phenomenon across human abilities or are strictly limited to academic skills.”

“This study draws on data from over 157,000 individuals across 30 countries, which we believe gives particular weight to the consistency of the findings. More broadly, this is an area of research that would benefit from being evaluated on empirical grounds, and we hope the scientific conversation around these questions can, at some point, be driven more by data rather than prior ideological assumptions, from any direction.”

The study, “Beyond Mean Scores: Sex Differences in Literacy, Numeracy, and Problem-Solving as Intraindividual Strengths Across Age Groups,” was authored by Marco Balducci and Waseem Haider.