In his Commemoration Day address this year, the Rector, Sir Keith O’Nions, recalled a conversation he had with an alumnus of Imperial. The alumnus, who graduated in 1966, told him that in her time here only 180 of the 3500 students were women. Sir Keith told those of us gathered at the Royal Albert Hall that he had looked up the statistics and this had been, in fact, a slight overestimate. He used this as an example of the “massive changes” that have taken place at the college over recent years.

A jump in the number of female students of the college from around 5% in the 1960s to nearly 35% today is a substantial one, and is indicative of a general change in the number of women pursuing degrees and careers in the sciences. However, there is still a long way left to go before we achieve an equal number of women and men in science.

A study published in the journal Psychological Science recently found that the sexism of individuals in a society leads to gender inequality in the society as a whole. This is not a surprising result, but the study is noteworthy because of its size: it covered 57 countries. The conclusion is clear — if increased equality is the goal, then individual attitudes must change.

In 1966, only 22 college accommodation rooms were available to women. Women were not allowed into the Union Bar until 1972. Today, this same discrimination does not exist, but there still exist gender stereotypes could damage women’s chances of a career in science.

When a stereotype — for example, “girls can’t do maths” — is reiterated, it can do more damage than you might expect. One study showed that when telling a group of students that an exam was designed to test what makes some students better at maths than others, girls did worse than when they were told that both genders generally perform equally on the test. This is because of an effect known as “stereotype threat”. Stereotype threat has also been seen when women simply had to record their gender at the start of an exam, or were in the minority during the exam.

A report published by the UKRC in 2010 found that, of the 5.5m people working in science, engineering and technology occupations in the UK, only 12.3% were women. The gender pay gap for science and technology professionals was 11%. The loss to the UK economy by qualified women scientists, technologists and engineers working below their level of qualification or being unemployed was estimated to be £2bn.

Sexism does not need to be overt to be damaging. Small things — an offhand comment, a stupid joke — can add up over time to make a big difference. The sooner we become aware of this, the sooner we will see equal numbers of men and women doing science. And that will benefit all of us.