# Interpreting the conjunction fallacy

## Salvador Mascarenhas, NYU

### Abstract

In a seminal paper in 1983, Tversky and Kahneman showed that, with certain
choices of content, human reasoners will consider a statement of the shape 'A
and B' to be more probable than 'A'. According to probability theory, this is
a fallacy, for the probability of a conjunction of independent propositions
has to be less than or equal to the individual probabilities of its conjuncts.
In this talk I present work in progress arguing that the conjunction fallacy
is no fallacy at all, and can in fact be derived under reasonable assumptions
about the interpretive processes involved.