“How many thoughts can our brains come up with?” wondered the 11-year old son of cognitive scientist Iris van Rooij. The mother-and-son twitter poll found its way all around the world.

Ilaij (11) and Iris van Rooij (Donders Institute) like to discuss interesting things with each other. Last week they talked about whether it is possible not to think anything at all. ‘That’s when I asked him a question from my discipline,’ says Van Rooij. ‘Can a human brain think, in principle, a finite or an infinite number of thoughts?’

Harvard

Ilaij was immediately convinced that the answer was ‘infinite’. ‘I told him that I thought so too, but that many other people have different ideas,’ says the cognitive scientist. ‘This fascinated him. He wanted to know what they thought, and why. Then he came up with the idea to create a poll on Twitter.’

In hopes of reaching 100 votes, mother and son created the Twitter poll together. To their great surprise, the tweet was retweeted over 2000 times, including a retweet by Harvard. Over 50,000 people responded to the poll.

More than 55% of the respondents think that the answer to the question is ‘infinite’. Many of those who answered explained their decisions. Van Rooij: ‘One of the most common arguments was that we can think of any number, for instance. One, two, three, and so on. And numbers are infinite.’ People who thought that the answer was ‘finite’ often argued that our brain only has a finite number of neurons and that our lives are finite.

Curiosity

An earlier tweet by Van Rooij about academic equality was also retweeted over 1250 times. What is her secret? ‘This time my son went viral, not me. His poll actually reached a lot more people than my earlier thread,’ she says, putting her success into perspective. ‘I think that the topics of both tweets appeal to a lot of people. The tweet about the brain piqued the curiosity of many people. People got caught up in the discussions that I followed with great interest.’