  In this paper we present quantum-like (QL) representation of the
Shafir-Tversky statistical effect. We apply so called contextual approach. The
Shafir-Tversky effect is considered as a consequence of combination of a number
of incompatible contexts which are involved e.g. in Prisoner's Dilemma or in
more general games inducing the disjunction effect. As a consequence, the law
of total probability is violated for experimental data obtained by Shafir and
Tversky (1992) as well as Tversky and Shafir (1992). Moreover, we can find a
numerical measure of contextual incompatibility (so called coefficient of
interference) as well as represent contexts which are involved in Prisoner's
Dilemma (PD) by probability amplitudes -- normalized vectors (``mental wave
functions''). We remark that statistical data from Shafir and Tversky (1992)
and Tversky and Shafir (1992) experiments differ crucially from the point of
view of mental interference. The second one exhibits the conventional
trigonometric ($\cos$-type) interference, but the first one exhibits so called
hyperbolic ($\cosh$-type) interference. We discuss QL processing of information
by cognitive systems, in particular, QL decision making as well as classical
and QL rationality.
