Women who earned a 4.0 grade-point average in high school could have roughly the same leadership prospects as men who flunked their classes, according to a new study.

The findings from the University of British Columbia are based on career surveys and high school transcripts for nearly 5,000 people born in the U.S. between 1957 and 1964.

Researchers used that data to create a predictive model for professional success – defined solely by how many people a man or woman supervises at work – based on an individual's GPA.

The findings were a disappointing surprise to study co-author Dr. Yue Qian, an assistant professor at UBC's sociology department.

"We expected gender disparities, but we didn't expect them to be this big," Qian told CTV News.

According to their model, men who received straight As in high school could expect to eventually supervise an average of 13.3 workers. Women with the same grades were only predicted to supervise five workers – just one more than men who failed their classes.

The difference was even starker among men and women who became parents.

Fathers who earned perfect grades in high school were predicted to oversee an average of 18.8 employees. The number of predicted supervisees dropped to four among mothers with the same GPA, tying them in the modelling with fathers who flunked.

Qian acknowledged that a "bit of extrapolation" was required for their model, as there were very few people who had 0.0 GPAs in the data they used. The bottom line for Qian and her co-author, Dr. Jill Yavorksy of the University of North Carolina Charlotte, is that there is a clear imbalance that needs correcting.

"Overall, our results reveal that suppressed leadership prospects apply to even women who show the most promise early-on, and highlight the vast under-utilization of women's (in particular mothers') talent for organizational leadership," they wrote in the abstract for their study.

The pair pointed to previous research that could help explain the massive gap in prospects, including studies that found household labour often falls disproportionately to women.

"Mothers tend to take disproportionate child care responsibility, and research has long documented a lot of structural barriers that women face when they rise through the corporate ranks," Qian said.

The researchers also discounted the notion that men might have a "more natural propensity to lead," noting that women in the study were at least as likely as men to have taken part in high school government.