Underlying this hypothesis is the assumption that individuals are subjects with a wish to interact with its surroundings and with a concept of "psychological time".
-Psychological time must here be understood as a sense of passing time in spite the fact that nothing much is really happening for a captive individual in a little barren cage, neither on the inside, nor the outside, level. Another possible interpretation of psychological time could be a "sense of meaning".-
If an individual is placed in circumstances, which limits the performance of natural behaviour, the individual will experience a deterioration of its abilities to interact with its surroundings.
* In this "deterioration-phase" the individual will investigate the cage, try to escape and so on.
* After a while the individual slides into a phase characterized by "frustration" of these limited possibilities.
* After yet a while the individual enters the "Boredom phase". At this point in time the psychological ability to sense the passing of time is significantly diminished. This sense of time is important to maintain a sense of meaning and therefore the individual compensate by switching to a more "physically-based" sense of time. It is in this phase that the stereotypic behaviour first emerge ("Developing stereotypies").
* Since the surroundings obviously do not change in spite that the individual now has tried out its last strategy, it ends up in the "terminal phase", characterized by "depression/anxiety". In this phase the stereotypic behaviour will be established and the individual will now base its perception of time to a very high extent on this physical activity - all according to the hypothesis.
The "Subjectivity" innate in this hypothesis is dead certain not just limited to Homo sapiens but disregarding the appeal this particular hypothesis might have, it will in practice be difficult to verify since access to the mental processes in other species than our own until now seen rather in-accessible. Still, thought-provoking results has been achieved during experiments learning gorillas, chimpanzees and parrots sign language.
A whole different type of hypotheses which slides into the physiological level concerns Arousal, which is a very diffuse concept that deserves a bit of attention first:
Next topic:
The concept of "Arousal".