Thwarted again!

When ethologists, who study animal behaviour, looked into the weird behaviours that are typical of many animals raised in captivity they were puzzled.  For example, they witnessed animals biting at their own fur, feathers or hair or at those of other co-caged animals. The range of animals who expressed this sort of thing included parrots, sheep and mice to name but three.  They were puzzled because they could see no relationship to the weird behaviour and the environment in which it took place.  In short, the behaviour could not be directly said to be related or caused by the situation.  It was from this puzzlement that the concept of displacement behaviour emerged.

Three mechanisms are believed to be responsible for these weird displacment behaviours: (1) early environmental deprivation (2) the disruption of habitat-dependent processes and (3) the thwarting of behavioural response rules.  

Firstly, cases of environmental deprivation include animals reared in isolation or away from maternal care.  Secondly, the disruption of habitat dependent processes may include not giving animals the right kinds of foods or nesting materials so that behaviours dependent upon these environmental aspects cannot be properly expressed. Thirdly, animals in captivity are often physically prevented from behaving in natural ways such as a cage that restricts movement or which prevents it from achieving an ongoing goal.

The basic idea is that when an animal is continually frustrated or where the environment means that it cannot find an adaptive solution to an environmental problem the brain wiring is disturbed and these odd behaviours come to the surface.  But why, for example, hair pulling and not a different behaviour emerges is, as yet, unknown.  However, the link between animals in captivity showing this kind of a problem and people who pull out hair seems one too big to overlook in my opinion.

If there is one thing I would hope to get from this blog, it is that more and more people consider these aspects when they seek to understand hair pulling.

References:

 

Akgul, Y., Agaoglu, Z.T., Kaya, A., Sahin, T., (2000) The relationship between the syndromes of wool eating and alopecia in Akkaraman and Morkaraman sheep fed corn silage and blood changes (haematological, biochemical and trace elements). Israel Journal of Veterinary Medicine 56: 23-37.

 Bordnick P.S., Thyer B.A., Ritchie B.W., (1994) Feather picking disorder and trichotillomania: an avian model of human psychopathology, J. Behav. Ther. Exp. Psychiatry 25 (3) (1994), pp. 189–196.

Dias R, Robbins T.W, Roberts A.C (1996) Disassociation in prefrontal cortex of affective and attentional shifts. Nature 380: 69-72.

Kalueff, A.V., Laporte, J.L., Bergner, C.L. (2010): Neurobiology of Grooming Behaviour (Cambridge University Press)

Schrijver N.C.A., Wűrbel, H.: (2001) Early social deprivation disrupts attentional, but not affective, shifts in rats. Behav Neurosic 115: 437-42.

Wűrbel H (2001): Ideal homes? Housing effects on rodent brains and behaviour. Trends Neurosci 24:207-11.