The Great Britain IQ test

Take it online here

the test was put online in 2019, before the Covid pandemic swept the world, and the researchers continued to ­collect data well into 2020, when the outbreak was at its worst.

By this point they’d included questions about whether people had had Covid and, if so, how it had affected them.

They found that people who had been infected scored lower on the IQ tests, particularly when it came to something called ­executive function, a measure of ­mental skills such as memory, ­flexible thinking and self-control. If your executive function is affected, this can make it hard to focus, follow directions and ­handle emotions.

The team have since completed a larger study involving more than 112,000 people, which was published last month in the New England Journal of Medicine.

This confirmed the long-term impact that Covid can have on our brains. People who had a mild infection lost a couple of IQ points, but those who developed long Covid saw an average fall in IQ of about six points.