In a previous post we discussed computational vs ”biological thinking” and the question of why we assume that chunking the world in a specific way is automatically right. The outcome was that it is not obvious why the sentence

(i) Linda is a bank teller and a feminist

should always be analysed as containing two propositions that each can be assessed for truth and probability. It is quite possible that given the description we are given the sentence actually is indivisible and should be assessed as a single proposition. When asked, then, to assess the probability of this sentence and the sentence

(ii) Linda is a bank teller

we would argue that we do not compare p & q with p, but x with p where both sentences carry a probability and where the probability of x is higher than the probability of p. Now, this begs the question of why the probability for x – Linda is a bank teller and a feminist – is higher.

One possibility is that our assessment of probability is multidimensional – we assess fit rather than numerical probability. Given the story we are told in the thought experiment, the fit of x is higher than that of p.

A proposition’s fit is a compound of probability and connection with the narrative logic of what preceded it. So far, so good: this is in fact where the bias lies, right? That we consider narrative fit rather than probability, and so hence we are being irrational – right? Well, perhaps not. Perhaps the idea that we should try to assess fragmented propositions for probability without looking at narrative fit is irrational.

There is something here about propositions necessarily being abbreviations, answers and asymmetric.