Statistician Christl Donnelly was at an academic conference when she spotted a senior researcher by the coffee table. She knew he had an interest in her research on infectious diseases, so she decided to introduce herself.

"When I came up to him, he was pouring himself a cup of coffee," Donnelly recalls. "And he said, 'Oh, should I not be pouring coffee for myself?' and handed me the coffee and his cup." 

Today, scientists around the world are marking the International Day of Women and Girls in Science. But now a new report confirms that experiences like Professor Donnelly's are far from uncommon.

According to a study by GenderInSITEGenderInSITE promotes women in science, innovation, technology and engineering. , an initiative aimed at promoting women in science, patriarchalA society in which adult men have a monopoly on power. In these societies, men tend to hold all political positions, and women and children are also expected to obey the men in their families. attitudes and gender stereotypes mean women remain under-represented in science careers worldwide. 

The statistics are troubling. Women make up only 17% of members of scientific academies. For mathematical sciences, this figure falls to just 8%.

For many female scientists, the data tells them something they already knew. Female researchers tend to have shorter, less well-paid careers. They are passed over for promotions, under-represented in journals and given smaller research grants. 

Campaigners warn that those who believe patriarchal ideas are a thing of the past are mistaken. In 2015, British Nobel prizeOne of a set of prizes, laid out in the will of Swedish chemist Alfred Nobel, given each year to people who "have conferred the greatest benefit to humankind".  winner Sir Tim HuntThe biochemist was awarded the 2001 Nobel Prize in Physiology or Medicine for discovering the protein molecules that control the division of cells.  provoked outrage when he complained that women "cry" in labs when criticised and fall in love with men they work with. 

But others say signs of change are appearing. Today, more women than ever are starting careers in science. 

Data from GenderInSITE shows that between 2015 and today, women's leadership in science governing bodies has risen from 21% to 29%. And South Africa's Youth Academy of Science has more female membersThe academy has the highest percentage of female members in the world, at 57%.  than males. 

Around the world, women in science are achieving extraordinary things. Neuroscientist Katrin Amunts is building a 3D map of the human brain. Microbiologist Linda Amaral-Zettler is studying life forms on ocean plastics. Biologist Laura Boykin is bringing food security to East Africa by making insect and virus-resistant cassava crops. 

"As a woman of colour in STEMScience, technology, engineering and maths. STEM is a term used to group these academic disciplines. , I see the opportunity to add my voice to the chorus of women redefining what it means to 'be' or 'do' scientific work," says Jedidah Isler, an astrophysicist researching supermassive black holes. 

There is no doubt: encouraging female participation in science is vitally important for women and girls. Gender equality is enshrined in international human rights law.

But including women is also key to scientific endeavour itself. Diverse perspectives spark creativity and new ideas. 

For astronomer Lucianne Walkowicz, studying the stars outside our solar system made her appreciate the challenges humans face on Earth. "We need the brightest minds to create the future we want to see - and that means making science open and accessible for all." 

Yes: The answer is obvious. Women in science are constantly belittled, ignored and passed over in favour of male colleagues. It is no wonder that many choose to leave STEM subjects altogether.

No: Attitudes have changed dramatically over the last century, and even the last decade. From astrophysics to AIA computer programme that has been designed to think. , women are doing remarkable things in science. We should not ignore their achievements.

Or... The data is clear. Women are still under-represented in science. But the statistics alone cannot tell us why women are not continuing in STEM careers - or if patriarchal attitudes alone are to blame.