Imagine what a mathematician looks like. Draw the mathematician that is in your mind. What do they look like? What are they doing? Picker and Berry (2000) conducted a study where they asked 12-13 year olds from 5 countries (USA, UK, Finland, Sweden, and Romania) to draw a mathematician. Both males and females drew mostly males, with the exception of females from the UK as seen from the table below.
(Table from Picker and Berry 2000)
Already, before these students reach high school, a lot of females see mathematicians as a male-dominated field. Not only this, but quite a handful have negative connotations to the role, as seen in these examples:
Though this article is from 2000, the idea is still important and relevant. I have asked students from my classes to draw a mathematician and though about 90% of my students are female, the majority drew a male mathematician teaching. Not only do we have to show that mathematicians can look like anyone, but we have to expand their minds on what a mathematician does.
Knowing this, I spend the first couple days of school strictly on mindset. Students may come into class already hating math so it is important to establish the idea that everyone can be good at math and everyone is a mathematician.