  The extended model of two-leg Ising spin ladder with trimer rungs and next
nearest neighbor interaction (NNN) in an external magnetic field is studied
using the transfer matrix and linear renormalization group methods. In the
standard version (with the same only NN interactions in both legs) such a
ladder exhibits very interesting behavior - a frustration driven extremely
sharp phase crossover at finite temperature which resembles a phase transition,
impossible in one dimension. It is shown that in all considered cases with
different interactions in each leg (assymetric ladder), with NNN interactions
and in the presence of small external field such a crossover takes place when
the point at which the effective interleg coupling vanishes coincides with the
point at which the interleg correlation function exhibits an inflection point
accompanied by the specific heat maximum. A hypothesis is formulated that to
describe an abrupt change in political view of the people it is not necessary
to resort to a concept of a phase transition, controversial for social systems.
In some cases, this phenomenon can be understood as a phase crossover triggered
by the level of frustration. The source of this frustration is proposed as an
internal conflict between two areas of attitudes of the society members,
personal and economic, which are shaped by personality traits possibly modified
by life experience.
