The process ofclassical conditioning was the first of many phenomena introduced inbehaviourist psychology in order to try and explain the many different ways inwhich behaviour can be learned – whether in the lab or natural environment.Biological constraints of classical conditioning are all the different factorswhich affect how easily classical conditioning may occur, with some behavioursbeing more easily learnt and retained than others.
This is known as biologicalpreparedness. It is the idea that as a result of our biology, certain behaviours– which can be deemed as more ‘useful’ – are more easily learnt than others. An examplebeing that fears of snakes can be more easily conditioned onto someone than afear of a house. As this was highly discussed in early psychology, manybehaviourists set out to investigate whether there were biological constraintswithin classical conditioning….
In 1975, Ohman et al.conducted research investigating whether there was a biological preparedness todevelop phobias of certain objects. It studied this through researching if phobiasof snakes were able to be easier conditioned than phobias of non-fearfulstimuli such as faces and houses.
In order to investigate this, Ohman et al. (1975)had 64 participants who were split into groups of either seeing the fear-relevantcontent such as a snake or the fear-irrelevant content of houses or faces for atotal of 8 seconds before they were each given an electric shock. Eachparticipants skin conductance levels was measured in order to identify levelsof fear.
The higher the levels of sweat displayed meant participants wereexperiencing higher levels of fear. Results from this study was able toshow that it was much easier to condition a fear for snakes compared to the non-fearfulstimuli of a house or face. Prior to conditioning the skin conductance of allthe participants was low (skin conductance rate?) however, uponbeing presented with the fearful or non-fearful stimulus, this changed. Afterconditioning, when presented with the image of the snake, participants in thiscondition had an average of 0.
62 conductance while those in the house and face conditionhad an average skin conductance rate of 0.048. This higher skin conductancelevel for those in the snake condition shows how participants had beenconditioned more to show fear towards a snake compared to the house or face.
Alongwith this, after a period of time, Öhman et al. (1975) were able to find thatthe conditioned fear of snakes was more resistant to extinction compared to theconditioned fear of houses or faces. This is because, during the extinctiontrials, only those in the fear relevant conditions – such as the snakecondition – were able to resist extinction while in the fear-irrelevant trialsthis wasn’t possible and extinction quickly occurred. Along with this, onlyparticipants who witnessed the fear relevant CS of the snake had physically reportedhigher levels of fear towards it after conditioning compared to their initialrating.
This along with the higher skin conductance levels all showcase how itmay be easier to condition fear of a fear relevant object such as a snakecompared to a fear irrelevant object. Results from thisstudy are able to give an insight into how there may be biological constraintspresent in classical conditioning. It is able to suggest that we may bebiologically predisposed to acquire phobias to different situations which canbe perceived as life threatening. This may be a result of evolutionarydevelopment where it is more beneficial for human survival to fear certainsituations over others. For example, having a phobia of snakes may help humansavoid them in future which in turn may lead to the survival of the human race.This may have been especially relevant many years ago where the threat ofgetting killed by snakes was imminent and so those who avoided snakes, survivedand reproduced thereby passing down genes that contribute to these fear responsesmeaning they will inturn be able to easily form a fear of snakes.