![Wason cards [CC-BY-SA-3.0 Steve Cook]](https://www.polypompholyx.com/wp-content/uploads/2013/10/wason_cards-300x118.png)
The Wason card problem is a well-known psychological test that probes how people think about hypothesis testing. The version I use in one of my first-year lectures is shown below. I think the original version used letters and numbers, but I’m a biologist, so obviously I use pictures of dead pets instead of numbers. We …