Recently we have had some studies showing the remarkable intelligence of crows as problem solvers and their ability to use tools. Given this information, it was thought that they would also be good at inferring causal relationships. But as often happens, we find that intelligence is not a simple thing and that success in one aspect of it does not necessarily transfer to other areas.
Ed Yong reports on a study in which crows were tested for their ability to infer causal relations and the results compared to that of babies.
You drop a block onto a box, and a toy pops out. If a baby was watching you, she could deduce that your action caused the happy arrival of the toy, because she understands cause and effect. She’d also realise that she could trigger the same event by placing a block on the box herself, because she can use her knowledge to actively shape her world.
These two abilities—understanding causality, and using that understanding—seem so simple and mundane to us that it feels weird to lay them out, and weirder still to separate them. But they are separate. That much becomes clear when you study an animal that can do one of these things and not the other.
But the crows failed to make the connection while two-year old infants succeeded quite easily on a similar test.
Here is a video of the experiment.
What does this mean?
The crows’ failure means that the ability to “create causal interventions”—that is, to do things that result in a desired effect—can be separated from the ability to understand causality in the first place. We have both; crows (at least as per this study) only have the latter. “We have the complete package, so it’s really hard for us to know what’s particularly special and what isn’t,” says Taylor. “Studies like this provide a more nuanced view of what’s going on.”
Indeed, Taylor speculates that our ability to learn about causality through observation alone could have been one of the driving forces behind our success as a species. “It seems so obvious to a human but that’s almost the point,” he says. He’s now talking to colleagues who work with primates to see if our closest relatives can pass the same test.