Our lives are full of sequences: a trip to the zoo requires planning multiple steps (When to go? How to travel? Which animals to see first?); when we tell stories we remember in which order things happened; and when we bake, we need to follow the correct sequence of actions. Some researchers think that humans are unique in their abilities to remember sequences- but what about chimpanzees? My team and I are interested in how well chimpanzees can tell different sequences of actions apart.

For our study, I use a long box whose top is covered with mesh and carries two things: a tube and a blue box. The chimpanzees know that the blue box always has a small treat for them (e.g., a peanut). They also learn that sometimes, when they point to the tube, I will give them a treat that they like even more- a grape! But how to get this super nice treat? For this, the chimpanzees need to pay attention to the order of my actions!

I can do two things with the tube: put a paper towel inside (“action A”) and put the super nice treat inside (“action B”). I combine these actions to make four sequences: “AB” - I put the towel first and then the treat. The towel blocks the tube and prevents the treat from falling through the mesh into the long box. When a chimpanzee selects the tube, I tip it upside down and the treat comes out! Hooray! But don’t select the tube when you see the other three sequences (“BA”, “AA”, “BB”) – select the blue box instead! Can you figure out why?

How long will it take the chimps to learn that the sequence of the actions matters?