All of us have fears that we believe are due to our individual personality. However, new research now proves that genetics has a role to play here. The research by Dr John Hettema of the Virginia Commonwealth University and his Swedish colleagues, which involved the study of twins revealed that almost half of the body’s fear conditioning appears to be inherited.
They studied 90 pairs of identical twins and 83 pairs of fraternal (or non-identical) twins. In the study, the twins were shown a series of different images, some frightening, such as snakes and spiders, and others neutral, such as circles and triangles. The subjects were also given a mild electric shock while viewing some of the images.
Identical twins have similar genes, but fraternal twins are genetically different – as different as children born separately from the same parents.
During the tests, the researchers measured the subjects’ skin electrical conductivity, which normally increases in states of anxiety and fear due to increased output from sweat glands. When the results were analysed, the researchers found that the identical twins had the same responses; but the non-identical twins had differing responses.
“Now we can say that the fear conditioning process in humans is controlled, at least to some extent, by genetic factors,” he said.