Confident girls get better grades. (AP Photo/The Knoxville News Sentinel, Paul Efird)

“Believe in yourself” is not just a bubble-lettered cliché on a third grade teacher’s bulletin board. It’s an economic strategy, new research suggests.

Boosting the confidence of young girls may help close the gender gap in school performance  -- and push more skilled workers into the workforce, according to an OECD published Thursday.  “Aptitude knows no gender,” researchers wrote.

Data shows girls around the world lag behind boys in math and science, but confidence is a key factor. “The strong relationship among self-beliefs, gender and performance in mathematics and science hints that countries may be unable to develop a sufficient number of individuals with strong mathematics and science skills partly because of girls’ lack of confidence in their abilities,” the study's authors found.

By now, this cycle is depressingly familiar: Girls grow up. They go to college. They opt out of STEM majors. They’re dramatically underrepresented in engineering and technology, even as jobs proliferate.  Only 14 percent of women entering colleges in OECD-examined countries chose a science-related field of study in 2012, the last year measured, compared to 39 percent of men.

Academic underachievement is a missed opportunity for growth, economists argue. Social forces drive it. A wide body of evidence tells us this “mathematics anxiety” begins with parents and toy-makers and teachers (who, a recent study shows, can subconsciously grade girls more toughly).  “Engineer” doesn’t fit neatly into the traditional female narrative. Role models are scarce. Success is harder to envision. And intimidation can overpower natural curiosity.

The OECD paper devoted 29 pages to the phenomenon in a chapter called “Girls’ lack of self confidence.”

American girls score in the bottom third in math

The U.S. is ranked 35th of 64 countries in this OECD analysis of student math achievement. Parts of China, meanwhile, where the subject is more culturally exalted, topped the list.


Courtesy of OECD

 

Lack of confidence hurts girls in the classroom

The starkest gender differences emerged when students expressed how they perceive their own abilities. Girls showed significantly less confidence when it came to math and science than their male peers.

Doubt and poorer performance appear to be linked, the OECD study found. A difference of one unit on the index of mathematics self-efficacy, seen below, is associated with a 43 PISA score-point difference in performance among the 10% lowest-performing students and a 53 score-point difference among the 10% highest-performing students.


Courtesy of OECD

 

How children spend their free time matters

Top-performing girls around the world largely trailed top-performing boys. Researchers wondered if girls’ extracurricular activities, often influenced by what seems culturally appropriate, impacted their scores. Boys were more likely to play video games, for example, or with chess sets. Girls tended to read for pleasure.


Courtesy of OECD

 

The gender gap in science

Girls felt better about their scientific abilities -- but still answered less confidently than boys. One index of science self-efficacy, similarly, is tied to a 30 score-point difference in performance among the 10% lowest-performing students worldwide and a 41 score-point difference among the 10% highest-performing students.

 


Courtesy of OECD

 

Survey responses don’t prove girls are self-fulfilling a bad grade prophecy. They can, however, show us a global trend of self doubt.