Understanding causality

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.



  1. flex says

    Jean Piaget studied the development of human conceptions of causality in his work. I enjoyed reading “The Child’s Conception of Physical Causality” some years ago. I suspect that it may be somewhat outdated now, but what I loved about Piaget’s work was that he included transcripts of the conversations he had with children.

    It made his work not only interesting and comprehensible, but allowed the reader to see how closely his conclusions matched the readers.

    As far as this particular test goes, the causal nature appear to be evident to humans early on. However, Piaget found that more complex understandings of causality develop through the developmental period of the child until at around the age of 9-12 children started to exhibit the same understanding of causality as adults.

    Which isn’t to say that I haven’t found the occasional adult who’s comprehension of causality would be on par with crows. 😉

  2. kathleenmcnamara says

    I wonder if has anything to do with the fact that the crows watched humans do it. I mean, they might not be able to make the leap between what a human did and some action they can do because of the differences in their bodies. This is just pure speculation on my part, but it seems like it would be easier for a human baby to figure it out because the baby has the same body parts as the adult doing the experiment, so it’s a little less of a leap than it would be for a crow.

  3. Chiroptera says

    …it was thought that [crows] would also be good at inferring causal relationships.

    Huh. Human Republicans haven’t figured out causal relationships. Kind of sad when the default expectation is that creatures with only a few grams of brain matter are smarter than one of the dominant poltical forces in the US.

  4. busterggi says

    I’m seconding kathleenmcnamara, more study needs to be done. It wouldn’t hurt to study why some humans are more susceptable to assigning cause to undeserved correlation.

  5. says

    That just means the crows are smarter than the two year old children because the crows understand that correlation does not imply causation. :-p

  6. Mano Singham says


    That’s an interesting hypothesis that had not struck me. I wonder if the researchers are aware of it. If they could train a crow to do it, they may be able to do the comparison.

  7. Seth says

    And I’m curious about aspects of consciousness that human minds are incapable of experiencing, in the same way that crows are (evidently) incapable of understanding causality. The article says that humans have “the complete package”…but is that really true? Or are we only one step above crows, and there exist many more steps above us?

  8. says

    Maybe I’m missing something but this seems to conflict with the whole ‘crows can use vending machines’ thing that came up awhile ago. There’s even (less credible, touted by Oprah) endeavours to get crows to collect rubbish and ‘vend’ it to get food rewards. Here’s a link to the vending machine crows:

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