Rational Emotive Behaviour Therapy (REBT) hypothesizes that the functionality
of inferences is primarily affected by the preferential and demanding nature
of rational and irrational beliefs, respectively. It is then, secondarily,
influenced by the functional and dysfunctional contents to which rational
and irrational beliefs, respectively, refer. This hypothesis was tested by
asking 96 participants to imagine themselves holding one of four specific
beliefs: a rational belief with a preference and a functional content, an
irrational belief with a demand and a dysfunctional content, a rational
belief with a functional content and no preference, and an irrational belief
with a dysfunctional content and no demand. Participants imagined themselves
holding their belief in an imaginary context, whilst rating the extent of
their agreement to 14 functional and dysfunctional inferences. Contrary to
REBT theory, results indicated that rational and irrational beliefs had the
same magnitude of effect on the functionality of inferences, whether they
referred to a preference/demand+contents, or only contents. The discussion
maintains that preferences and demands may not constitute the principal
mechanism through which rational and irrational beliefs affect the
functionality of inferences. Instead, consistent with Beck's
cognitive therapy, belief contents may constitute this primary
mechanism.