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?