Don´t trust anyone who uses 3D-graphs

| Michaela Nesvarova

Another day of CuriousU is here and another inspirational speaker is here with it. Today the main stage of the summer school festival belonged to Ionica Smeets, a famous mathematician who likes to bring science closer to the general public.

Photo by: Gijs van Ouwerkerk

´Don´t let graphs fool you!´ Smeets warned the audience and began explaining all the different ways numbers and graphs can play tricks on our minds.

Sneaky graphs

´Often the ´x´ on the graph doesn´t start at a zero, so the differences look much bigger on the graph than they actually are. Or the ´x´ is put upside down, so on the first glimpse an increase looks like a decrease, ´ listed Smeets. ´My favorite example is 3D-graphs, though. On those you can highlight a certain part by putting it into the forefront. That way even otherwise a small part of the graph looks rather substantial. It´s sneaky, but it works.´ And these are only a few of the methods people use to hide their often disappointing results on graphs.

Does ice cream cause drowning?

Besides an intentional misuse, there are also other ways numbers can lie to us. ´According to numbers, there is a correlation between the amount of drownings and ice cream. On the days when a lot of ice cream is sold, a higher number of people drowns. So should we ban ice cream?´ asked Smeets. Luckily, this connection between ice cream and drownings is mainly related to the fact that people both buy ice cream and go swimming on (the same) hot days, and therefore treating yourself to an ice cream doesn´t mean you have a death wish.

Do married men live longer?

Ionica Smeets offered many more examples of similar thinking errors. For instance, you have probably already heard that married men live longer than single bachelors. ´You might think that it is because they are well taken care of or - as my married friends sometimes say - the life might only seem longer to the married men. But the truth is that men with high life expectancy are more likely to get married, because they are generally healthy, rich and educated.´

So be careful around those sly graphs and numbers the next time you see them.

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