>> To actually run the experiment would have been to run the risk that a disordered environment has no effect on racial attitudes—a “null finding” that would mean he’d wasted his time, because journals aren’t usually interested in experiments that don’t prove something new.

This state of affairs has of course been remarked on before. Perhaps this could be rectified by creating an online journal with the title Null that only accepts papers recording experiments where the hypothesis was not proved. Of course it wouldn't make very interesting reading but after some time it might provide a useful reality check against novel claims, when a search in Null shows the x number of times a similar hypothesis was not proved. And the incentive to publish there would be to show that you are a credible scientist who sometimes, quite reasonably, comes up with hypotheses that when properly tested don't prove to be true.