Illiteracy is highest amongst the states of the Arabian Peninsula, and in Africa, around the Sahara. In those countries about 30% of men, and 40-50% of women are illiterate, by the UN definition. One of the causes of illiteracy is that someone who can manage to live without being able to read and write often does not have any reason to want to learn to read and write. Cultural factors also play a part, such as having a culture in which the oral tradition (communicating by speaking) is more important than writing. A tribe that mostly herds livestock, for example, may have no need to read or write. 