  In this paper, we show that organisms can be modeled as hierarchical Bayesian
control systems with small world and information bottleneck (bow-tie) network
structure. Such systems combine hierarchical perception with hierarchical goal
setting and hierarchical action control. We argue that hierarchical Bayesian
control systems produce deep hierarchies of goal states, from which it follows
that organisms must have some form of 'highest goals'. For all organisms, these
involve internal (self) models, external (social) models and overarching
(normative) models. We show that goal hierarchies tend to decompose in a
top-down manner under severe and prolonged levels of stress. This produces
behavior that favors short-term and self-referential goals over long term,
social and/or normative goals. The collapse of goal hierarchies is universally
accompanied by an increase in entropy (disorder) in control systems that can
serve as an early warning sign for tipping points (disease or death of the
organism). In humans, learning goal hierarchies corresponds to personality
development (maturation). The failure of goal hierarchies to mature properly
corresponds to personality deficits. A top-down collapse of such hierarchies
under stress is identified as a common factor in all forms of episodic mental
disorders (psychopathology). The paper concludes by discussing ways of testing
these hypotheses empirically.
