The general image that boys and girls are innately different is a difficult one. It develops into the stereotype that girls are less suitable for STEM and more talented at humanities, arts and caring professions, while boys are talented at STEM, but usually do not pursue humanities.
It has been shown that from a very young age, boys and girls are talked to differently (‘you are a nice girl’ vs. ‘you are a tough/brave boy’; Elliot, 2010) and different toys/activities are marketed to them (Elliot, 2010). This is illustrated by a clever study conducted by the BBC (2017) in which girls are dressed as boys and boys wear girls’ clothes. Adults who were asked to play with these children gave the ‘girls’ significantly “softer” toys like dolls and stuffed animals while ‘boys’ were asked to play with “hard” toys such as cars and Lego. Girls miss a chance to develop an interest for and abilities for STEM, if they are not exposed to toys promoting spatial awareness, persistence and other technical skills.
This leads to unconscious biases that are mirrored in gender-biased hiring and the publicity of the digital sector (computers are for boys).
In class, boys are more likely to be asked to solve new problems, while girls are asked factual questions (Skelton, Francis, & Smulyan, 2006). At home, girls are also helped with their maths homework more often, even without asking for help (Bhanot & Jovanovic, 2005). Because boys and girls are judged by different standards, in the end they are guided to study different subjects and do diffrent jobs, even when they have the same grades.
It is then no wonder that girls become less and less confident in their STEM skills and are afraid of failing at STEM. This might lead to girls answering fewer questions in class and participating less in experiments (and letting boys take over). This might work as a downward spiral.