When University of North Carolina students learned that a speech opposing coed dorms had been banned, they became more opposed to coed dorms (without even hearing the speech). (Probably in Ashmore et. al. 1971.)
This seems straight Bayes to me. The banning of the speech counts as information about the chance that you’ll agree with it, and for a reasonably low probability of banning speech that isn’t dangerous to the administration (i.e. speech that won’t convince), Everyone’s Favorite Probability Rule kicks in and makes it totally rational to become more opposed to coed dorms—assuming, that is, that you believe your chance of being convicted comes largely from rational sources (a belief that practical agents are at least somewhat committed to having).
When a driver said he had liability insurance, experimental jurors awarded his victim an average of four thousand dollars more than if the driver said he had no insurance. If the judge afterward informed the jurors that information about insurance was inadmissible and must be ignored, jurors awarded an average of thirteen thousand dollars more than if the driver had no insurance. (Broeder 1959.)
This too seems rational, though in this case only mostly, not totally. We can understand jurors as trying to balance the costs and the benefits of the award (not their legal job, but a perfectly sane thing to do). And the diminishing marginal utility of wealth suggests that imposing a large judgment on an insurance company causes less disutility to the person paying (or people, distributing that over the company’s clients) than imposing it on a single person. As for the judge’s informing the jurors that insurance information is inadmissible, well, again, they can interpret that instruction as information about the presence of insurance and update accordingly. (Although that might not be accurate in the context of how judges give instructions, jurors need not know that.) Of course, it seems like they updated too much, since they increased their awards much more when p(insurance) increased but is less than 1, than they did when they learned that p(insurance)=1. So it’s still probably partially irrational. But not an artifact of some kind of magical scarcity effect.
I agree with Bobvis: a LOT of this is rational:
When University of North Carolina students learned that a speech opposing coed dorms had been banned, they became more opposed to coed dorms (without even hearing the speech). (Probably in Ashmore et. al. 1971.)
This seems straight Bayes to me. The banning of the speech counts as information about the chance that you’ll agree with it, and for a reasonably low probability of banning speech that isn’t dangerous to the administration (i.e. speech that won’t convince), Everyone’s Favorite Probability Rule kicks in and makes it totally rational to become more opposed to coed dorms—assuming, that is, that you believe your chance of being convicted comes largely from rational sources (a belief that practical agents are at least somewhat committed to having).
When a driver said he had liability insurance, experimental jurors awarded his victim an average of four thousand dollars more than if the driver said he had no insurance. If the judge afterward informed the jurors that information about insurance was inadmissible and must be ignored, jurors awarded an average of thirteen thousand dollars more than if the driver had no insurance. (Broeder 1959.)
This too seems rational, though in this case only mostly, not totally. We can understand jurors as trying to balance the costs and the benefits of the award (not their legal job, but a perfectly sane thing to do). And the diminishing marginal utility of wealth suggests that imposing a large judgment on an insurance company causes less disutility to the person paying (or people, distributing that over the company’s clients) than imposing it on a single person. As for the judge’s informing the jurors that insurance information is inadmissible, well, again, they can interpret that instruction as information about the presence of insurance and update accordingly. (Although that might not be accurate in the context of how judges give instructions, jurors need not know that.) Of course, it seems like they updated too much, since they increased their awards much more when p(insurance) increased but is less than 1, than they did when they learned that p(insurance)=1. So it’s still probably partially irrational. But not an artifact of some kind of magical scarcity effect.