Perception is more than just seeing. Our version of reality comes both from the raw material we pick up from our senses and from the beliefs, desires, memories, and expectations that we use to interpret this material. For this reason, the way two individuals experience the word may be very different.
Most people have much the same sort of sensory equipment; their eyes, ears, and other senses work according to the same physical principles, and the sensory pathways in their brains are wired in similar ways. So, if two individuals witness the same event, the raw information that they take in will be more or less the same. But no two people will interpret this information in the same way. Those who share a common culture, background, and education are most likely to arrive at similar conclusions, but others may form widely variant pictures.
Perceptions can differ on a number of levels, from the purely sensory to the psychologically complex. For example, imagine that you are presented with a neutral tactile sensation, such as a vibration: if you expect it to be painful, you are likely to perceive it as such, but if you are told beforehand that the vibration will be pleasant, then you will probably experience it as pleasant. Similarly, different people’s interpretations of a neutral visual stim ulus, such as an irregularly shaped inkblot, can vary considerably. At a more complex level, we all interpret other people’s behavior according to the notions we already hold about those people. For example, if someone you know and like ignores you in the street, you will probably assume that they were lost in thought and did not see you passing. But if you dislike that person, you may see their action as a deliberate snub.
Cultural distortions
Prejudices like this pervade our every perception. Sometimes, the prejudice is individual, but often, it is shared by an entire culture. Take our ideas of beauty. Certain quali ties are perceived as beautiful by almost everyone because the human brain is wired to see them as such. For example, every known culture values facial symmetry, probably because it indicates health. But other concepts of beauty are clearly determined by culture: in the West, the ‘ ideal’ female form is slim, but elsewhere, a slender build indicates weakness or poverty, and an attractive woman is one with the sort of padding that sends well-heeled Westerners rushing to slimming clinics.
Theory of mind
Everyone’s perceptions are private. But in order to communicate and share understanding, we must have some idea of the world that other people construct in their minds. Not surprisingly, humans have evolved soph isti ca ted mechanisms for knowing how other people see things. One such mechanism is actually programmed into the human brain: psychologists call it the theory of mind.
Around the age of four years, normal children suddenly develop the ability to know intuitively that other people have a different point of view from their own. The emergence of this skill can be detected by a test in which the child is invited to watch a play acted out by a couple of dolls, Sally and Ann. In the beginning, Sally is given a sweet, which she places in a box before leaving the room. While she is away, Ann takes the sweet out of the box and places it in a different box. Sally then returns, and the children are asked:’ Which box will Sally think the sweet is in ?’
Children under the age of about four usually answer that Sally thinks the sweet is in the second box because they assume that the doll shares their view of the world and are unable to understand that Sally lacks the information that they have. Over this age, however, children realize that Sally’s view is different – that she did not see the sweet being switched, so she will expect it to be in the box she left it in. The inbuilt theory of mind that allows them to work out a person’s perspective is working.
Mirroring Emotions
The theory of and has its physi cal basis in brain cells known as mirror neurons. When activated, these cells produce a wide range of perceptions, emotions, and compulsions to act – just like other brain cells. But what is special about them is the way they are activated. Unlike most other neurons, which respond to a wide range of stimuli, mirror cells become active only when the response they produce in one person is first observed in another. So, for example, when one individual sees another making an expression of disgust, the ‘ disgust’ mirror neurons become active, producing a similar feeling. Mirror neurons give us built-in empathy – an automatic, intuitive sense of what another person is experiencing.
Contact through conversation
Another, more obvious way of finding out how another person is perceiving things is by talking. Telling each other about our experiences is important because it allows us to reconcile opposing views. Say, for example, a couple goes out to buy a sofa for their home. He wants black leather; she wants red velvet. They could state their desires, disagree, and feel mystified at the apparent error of the other’s way of thinking. But if he explains that he thinks the black leather is elegant and modern, and she explains that, to her, red velvet is warm and comfortable, they can at least try out the other’s point of view and perhaps see its merits.
Most everyday differences in perception that cloud our dealings with other people can be resolved through discussion and compromise. However, some are so fundamental that it is impossible to bridge the chasm between two different perceptions. Sometimes, a person’s view of the world is so bizarre that others cannot share it. People with such extreme perceptions are generally regarded as psychotic – dislocated from reality.
Delusions and psychosis
The most extreme psychotic perceptions are held by people who have schizophrenia. To people with schizophrenia, their perceptions seem to come from the real world, but they are actually made up largely of hallucinations. The sufferer cannot detect that the hallucinations are internally generated but instead seeks a plausible explanation for their origin – perhaps that voices have been beamed into his or her mind by evil aliens.
Schizophrenic delusions are warped perceptions that can sometimes lead to disaster. But there are many other, more subtle, ways in which non-consensual viewpoints can wreak havoc in society. The distorted world- views of despots like Hitler, egomaniacs like Idi Amin, and cult leaders like Charles Manson are far more threatening ‘than the delusions of schizophrenics because they are combined with a persuasiveness that seduces others into sharing their pathological assumptions. The terrible outcome of such distortions of social values underscores the importance of holding on to one’s sense of reality – and constantly testing beliefs against the widest range of evidence rather than relying on the opinions of selected others to confirm or deny them.
