Perhaps we hear that someone has been injured by a snake, for example, and we become afraid too. Almost no one is afraid of cars, even though almost everyone has experienced or witnessed a car accident in which someone got injured. For millions of years people who quickly learned to avoid snakes, heights, and lightning probably have had a good chance to survive and to transmit their genes. We have not had enough time to evolve a tendency to fear cars and guns. Another possible explanation is that people generally develop phobias for objects they cannot predict or control.
Lightning is unpredictable and uncontrollable.
Neuroscientists are finding that biological factors, such as greater blood flow and metabolism in the right side of the brain than in the left hemisphere, may also be involved in phobias. There may be other reasons why some phobias are more common than others. One is that we have many safe experiences with cars and tools to outweigh any bad experiences. Cross-cultural psychologists point out that phobias are influenced by cultural factors. The focus of cognition for a sufferer of this phobia is on the harm to others, not on embarrassment to the self as in social phobias in the West.