Ok, now that you've read through this story, ask yourself whether you agree with the following statement:

Imagine that scientists are trying to understand how people develop a particular trait, which they have come to call Trait X. The scientists have discovered a surprising fact about people’s genes. They have discovered that people’s genes work in such a way that almost everyone will end up developing Trait X. In fact, it turns out that children develop Trait X as long as their parents sometimes offer them at least a decent level of treatment. Now, just about everyone’s parents offer them at least a decent level of treatment at least sometimes. So, given the way people’s genes work, just about everyone actually does develop Trait X.

Once you've answered this first question, try considering a case that is almost exactly the same, except that the moral significance of the parents' act has been switched around (changes indicated in italics).

Imagine that scientists are trying to understand how people develop a particular trait, which they have come to call Trait X. The scientists have discovered a surprising fact about people’s genes. They have discovered that people’s genes work in such a way that almost everyone will end up developing Trait X. In fact, it turns out that children develop Trait X as long as their parents sometimes treat them badly.



Now, just about everyone’s parents treat them badly at least sometimes. So, given the way people’s genes work, just about everyone actually does develop Trait X.

And now consider the corresponding sentence:

Trait X is innate.

Richard Samuels and I tried giving people these cases in two different formats. Some people just got one case or the other (the 'case-based' version); others got both cases and were asked to think about whether the difference between them was relevant to innateness (the 'principled' version). The results came out like this:

In other words, when people got the case-based version, they were more inclined to say that it was innate in the morally good case than in the morally bad case... but then, in the principled version, this difference somehow disappeared. People overwhelmingly agreed that there was no real difference between the two cases.

But what if we turn to professional scientists? Surely, they are always answering questions like these using deeper principles, so it seems like we should predict that they will always show no difference between the morally good case and the morally bad one.

To address this question, we teamed up with Edouard Machery, Paul Griffiths and Stefan Linquist and tried running the study on a sample of scientists. Together, we recruited more than a thousand participants who were actively working in biology, genetics, neuroscience, linguistics or psychology. But when we tried the study out on them, we found a surprising result...

In other words, professional scientists are showing exactly the same effect we found in ordinary folks! They too are being influenced by moral considerations in the case-based version but not in the principled version.

We were curious to hear what people around here thought this might be telling us about the relationship between scientific judgment and folk judgment and, more specifically, about the role of morality in each. Definitely seems like there's something pretty puzzling going on here...

[The full paper is available here, but feel free to comment even if you haven't gotten a chance to take a look at it.]