Student becomes youngest PhD holder in Scandinavia

A 20-year-old from the Netherlands studying at Stockholm University has become the youngest doctorate holder in Scandinavia in modern times.

The university describes him as “probably the youngest in Sweden ever to complete a PhD” and the same age to the day as the current holder of the Dutch record.

On 9 April, Stefan Buijsman defended his PhD thesis: "Philosophy of Mathematics for the Masses: Extending the scope of the philosophy of mathematics". 

Born in Leiden in the Netherlands in 1995, he passed his masters degree in philosophy in Leiden in 2013 and had also studied computer science in his bachelor degree.

In a YouTube video he says that he has always done things earlier than those of the same age. He started school at four years of age, then skipped several years. He finished high school at 15 and earned his masters at 18.

In September 2014 he came to Stockholm for his PhD, which he completed in one and a half years.

Bujisman said taking a PhD was challenging. 

"It's been as difficult as you would expect a PhD to be. It was hard work, but I wouldn’t say that it was, for me, more difficult than how other PhDs have described their experiences,” .

“I never work more than 40 hours a week. So I do lots of other stuff too, like travelling and meeting up with friends.”

He said his work has been strongly influenced by his mentors.

"Without the large amount of help from my supervisors, Peter Pagin and Dag Westerståhl, my thesis wouldn’t have been finished, nor would it have been as good as it is now."

He has taken the move from the Netherlands to Sweden in his stride and his lack of Swedish has not proved a significant obstacle.

"My Swedish is, alas, still fairly bad. Living in Stockholm, and working at Stockholm University, is not something that requires Swedish, so I lack the necessary practice,” he said.

“As for the move from the Netherlands to Sweden, it’s been very easy. They’re very similar, and on top of that Stockholm is a wonderful place to live and work."

Buijsman’s thesis explored whether mathematics is real, or a story we agree upon and shows that philosophers failed to include non-experts in the theories.

He has surveyed the many theories on the nature of mathematics and how we learn mathematics, and argues that none of them describe the practices of ordinary people’s mathematics. For example, one theory says that we can only know that 1 +1 = 2 if we have a proof. But most people don't have a mathematical proof that 1 + 1 = 2, and couldn't give one if we asked.

“All of these theories are made with professional mathematicians in mind. That's a problem for philosophy. Right now, we have no idea what people are doing when they're taking a mathematics class in high school or calculating how much change they need in a store,” he says in a statement on Stockholm University’s website.

“I don't have an answer yet, but psychology and pedagogy can help us. They give us an idea of what abilities people can use when they’re doing simple mathematics. We then know what ingredients we can use when making new theories”

Buijsman has now received a three-year post-doc position that will keep him in Stockholm for that time. His career goal is to become a professor.

In an interview on YouTube, he said since his research so far has been about pointing out a problem, he now wants to solve that problem, by researching how we learn mathematics.

So what is his secret to such early success? “I tend to work faster than most people, no idea why,” he said. “If my supervisors hadn’t spent a lot of time helping me, it would have taken much longer.”