About 10 years ago I had a conversation with a civil servant about Britain’s chemical decontamination units. He was in charge of calculating where in the country the government should keep them. These giant trucks had specialist equipment that could respond quickly if there was an anthrax attack or similar on our shores. But at the time there was only a small number of them, so they needed careful positioning to ensure they could reach as much of the country as quickly as possible in an emergency.

It’s a decision that boils down to maths. It’s not an easy thing to work out either. It was a problem that I, as a mathematician, imagined had a number of top minds working to solve. Picture my astonishment, then, when I discovered that rather than some beautifully crafted numerical model, or some sophisticated custom-built software, the British government had left a question of such magnitude to one poor guy, working it out on his own. He was using an Excel spreadsheet. And we were having the conversation because his spreadsheet kept crashing.

In the 2010s we learned not to charge ahead without considering the ethics of forcing equations on human systems

I like to think that they’ve found a better solution to that problem in the time that has passed since. The truth is, I don’t know. But I do know this: some political problems would greatly benefit from the help of maths. That’s why, in his advertisement calling for young mathematicians and “assorted weirdos” to work at the heart of the government, No 10 strategy chief Dominic Cummings has a point. As he says, there really are some “profound problems at the core of how the British state makes decisions”.

Cummings insists the government doesn’t need “more drivel […] from humanities graduates” but rather young, eager data scientists, economists and physicists who understand the big ideas behind optimisation and prediction calculations.

There is some truth to this – there are a host of government questions that could benefit from a more mathematical take. In everything from bin collection timetables to Brexit policy, I’d love to see more decisions made on the basis of evidence over instinct. The big-data revolution has transformed the private sector, and I wholeheartedly believe it has the potential to profoundly benefit broader society too.

But (and there is a but) recognising the power of maths to transform the world is, in many ways, the easy bit; far harder is recognising its limits. In the past decade it has become clear that you can neatly split those who apply equations to human behaviour into two groups: those who think numbers and data ultimately hold the answer to everything, and those who have the humility to realise they don’t.

The 2010s were littered with examples from the first camp. There were those who claimed that, with enough data, you can predict at birth who will go on to become criminals (you can’t); those who said they could mathematically predict precisely where and when terror incidents will next occur (you can’t). Others claimed you could predict exactly which words to change in a Hollywood script to make it more profitable at the box office (nope); and, more recently, scientists have tried to predict the true pain levels of a patient based on their facial expressions (again, nope).

It was also the decade in which we learned the lessons of charging ahead without first carefully thinking about the ethics of forcing equations on to human systems. There were the stories about racist algorithms in the criminal justice system, and sexist algorithms designed to filter job applications. YouTube was accused of unwittingly radicalising some of its viewers. Indeed, some would argue that the world is still reeling from the consequences of mathematical equations gone awry, both during the time leading up to the 2008 financial crash and Facebook failing to consider the consequences of its newsfeed algorithms. I’ve even been guilty of it myself.

And herein lies my concern. People are not planets or solar systems; there isn’t some secret underlying equation that, if we can only find it, holds the solution to all our problems. The real world is messy, full of uncertainty and impossible to predict. Applying maths to the real world requires much more than mathematicians. It requires people who understand human society and culture – people, in short, who actually understand people.

It seems that Cummings is trying to reinvent the technocracy. But many of his ideas of how to do it seem to come from the era between 2004 and 2014 – a time of “move fast and break things” rather than the careful, strategic avoidance of unintended consequences that the world has moved on to since.

So, sure, bring on the mathematical geniuses, and make government more agile. Yet I can’t help but think that Cummings could probably do with spending a bit more time listening to the “drivel” of a few humanities graduates.

• Hannah Fry is an associate professor in the mathematics of cities at University College London