A new article in Biology Letters shows that under some conditions in which animals appear to behave “irrationally” (by apparently failing to conform to the Independence of Irrelevant Alternatives or even the Transitivity axioms of decision theory), the animal behavior may in fact resemble utility-maximizing strategies which also appear to violate those axioms. The optimal strategies’ current preferences are altered in response to the information conveyed by the current presence or absence of various alternatives.
These results probably shouldn’t surprise the most careful rational thinkers. For instance, “I prefer A to B when I believe more B is likely to be available later, and B to C when I believe more B is likely to be available later” clearly does not necessarily entail “I prefer A to B under all circumstances, and B to C under all circumstances”. But there is clearly a pitfall of tempting model oversimplification here. Although this new paper and most discussion of it is carefully putting scare quotes around “irrational”, the papers being cited purport to show “intransitive preferences”, “violations of rational choice”, “irrational decision-making”, and “irrational choices”, without obvious irony.
The non-Independence of superficially-Irrelevant Alternatives
A new article in Biology Letters shows that under some conditions in which animals appear to behave “irrationally” (by apparently failing to conform to the Independence of Irrelevant Alternatives or even the Transitivity axioms of decision theory), the animal behavior may in fact resemble utility-maximizing strategies which also appear to violate those axioms. The optimal strategies’ current preferences are altered in response to the information conveyed by the current presence or absence of various alternatives.
A press release about the article is available from the lead author’s university, U. Bristol. A news piece summarizing it is at Nature’s website.
These results probably shouldn’t surprise the most careful rational thinkers. For instance, “I prefer A to B when I believe more B is likely to be available later, and B to C when I believe more B is likely to be available later” clearly does not necessarily entail “I prefer A to B under all circumstances, and B to C under all circumstances”. But there is clearly a pitfall of tempting model oversimplification here. Although this new paper and most discussion of it is carefully putting scare quotes around “irrational”, the papers being cited purport to show “intransitive preferences”, “violations of rational choice”, “irrational decision-making”, and “irrational choices”, without obvious irony.