After reading this article you will learn about the biological, psychological, personality and cultural factors in perception.
A. Biological Motives:
Several interesting experiments have been conducted to see how needs like hunger, sex etc. influence perception. In one experiment by Levine, Chein and Murphy vague and blurred pictures were presented to a group of individuals who were deprived of food for different lengths of time- three hours, six hours and nine hours.
It was found that people who had not eaten for six and nine hours perceived the ambiguous images as pictures of food much more frequently than the group which had eaten only three hours previously. The group which had been deprived for nine hours, however, showed a drop in food-related perceptions- as if the hunger had gone beyond a peak of intensity and had died.
B. Psychological Motives:
Reward and Punishment:
It is common knowledge that reward and punishment influence the learning process. But it is less easy to understand how one’s perception of an object can be influenced in a similar manner. Solley and Santos used drawings of ‘Necker cubes’ as in the following manner (see Fig.7.19). In the altered cubes to the left and right only one perspective could be seen when seen for one second. The cube in the centre could be seen as having either perspective.
The experimenter verbally rewarded the perception of one of the altered cubes. It was found that as the experiment progressed, i.e. as the amount of verbal reward increased, the subjects perceived the natural cube more and more only in the perspective for which they have been rewarded. This incidentally also provides evidence for the role of learning in perception.
Values:
Different individuals attach different values to various objects. These differences result in differences in their perception of these objects. In their famous experiment Bruner & Goodman showed that poor children place a higher value on money than do rich children and this higher value results in an over-estimation of the size of the coins in their perception and memory. Further the amount of over- estimation was greater for the higher denomination coins than the lower ones.
The judgement of size, therefore, was being influenced by the judgement of value and desirability. One can think of many instances in everyday life in which we perceive the physical properties of objects differently depending upon our judgement of its value. For example, a fake necklace worn by a rich woman is often perceived as having all the properties of real diamond, while a genuine diamond necklace worn by a poor woman is seen as being cheap and artificial.
C. Personality Factors and Cognitive Styles:
Of the individual factors which influence perception, not only are those which vary from moment-to-moment and those which are determined by social factors, such as values and beliefs, but also those which are lasting characteristics of the personality. Cognitive style refers to the manner in which individuals differ in certain dimensions and the way in which they handle perceptual and cognitive information.
Witkin and others, in a series of experiments on cognitive styles and certain perceptual skills, discovered that it is possible to classify people along the poles of a general dichotomy called field dependent, and field independent. This dimension refers to the extent to which individuals are dependent upon the context or ‘field’ in their perceptions, thoughts, social judgements, etc.
A typical test of field independence is the Rod and Frame Test, in which the subject, deprived of other visual cues, has to adjust a rod to the true vertical, while overcoming the distorting effects of a tilted frame surrounding it. The field- independent individuals are able to overcome the influence of the field (i. e. the frame) and approximate the true vertical much more accurately than the field- dependent people.
Witkin found that this perceptual field independence was highly correlated with the social ability to be independent of others, the presence of a strong self-identity and with conceptual clarity. The field-independent people were more analytical in their approach to social or perceptual tasks, while the field-dependent people were more global in their approach.
Other styles of perceiving and judging have also been found. One interesting dimension, identified by Holzman and Klein, is the distinction between ‘levellers’ and ‘sharpeners’. It has been found that if people were shown a series of highly similar stimuli, with only very gradual variations in them, some people tend to ignore the variations, thus ‘leveling’ all differences from the norm, while others tend to be very sensitive to the slightest variations, thus ‘sharpening’ the existing differences.
It was found that ‘levellers’ tended also to be rather rigid in their beliefs, attitudes and social judgements. They tended not to perceive those elements of reality which ran counter to their existing beliefs, thus, seeing reality as validating the beliefs. Sharpeners, on the other hand, were more flexible, tending to notice all evidence which challenged their beliefs and assumptions, thus, having to change their beliefs to fit reality rather than misperceive reality to fit their beliefs.
Set:
The term ‘set’ refers to the factor of readiness or anticipation in a person at the time of perceiving particular objects or events. Set is the state of preparedness of the perceiver at any given moment. Knowing or expecting in advance what we may perceive can influence our perception.
This can be demonstrated by using the Fig.7.20. Show this figure to your friend and ask him to look at it carefully and tell you which alphabets they can see. Show the same figure to another friend and ask them what sort of tools they see in this figure, i. e. give one person an instructional set to see alphabets and another person an instructional set to see tools.
Exposure of the figure should be only for about a tenth of a second. Invariably, a person who has received suggestions that a particular thing is likely to be seen will actually perceive that thing. A person who is told that the figure shows certain tools will set one’s mind to seeking tool-like structures, and is unlikely to see alphabets and vice versa.
D. Cultural Factors:
Cultural influences play a vital part in perception. For example, members of the early tribal communities often develop different perceptual capacities compared to members who live in cities. Research studies on perception have shown that American children who live in cities could discriminate various geometrical designs and different shades of colours.
On the other hand, tribal children who live in wilderness showed a greater capacity for discrimination of different sounds and smells which appeared indistinguishable to children living in big cities. An interesting observation recorded by C.M. Tumbull in this connection was about the Bambuti pygmies of Congo who rarely venture out of the forest and are, therefore, not used to looking at far-off objects. Tumbull observed that from a distance, one of the pygmies could not recognise a herd of buffaloes.
On getting closer to the animals, he believed that they were getting magically larger in size. He was unable to grasp the fact that the buffaloes had actually remained constant in size. His eyes transmitted the same message to his brain as those of people who were brought up in other cultures. The only difference was in the way the pygmy interpreted the messages. His perception of the situation was different from Tumbull’s.
More recently, researchers like Berry, Dasen and others have found cultural differences in perceptual skills related to the field independence-dependence dimension. It was found that the more complex and ‘differentiated’ the physical and social environment in which an individual grows up, the more sophisticated and field independent is that individual likely to be- both in relation to the physical environment and the people.