The causes of dyslexia are not yet fully understood, but are believed to be largely hereditary. Other causes of dyslexia could include hearing impairment in early childhood, which could cause very young children to misunderstand the appropriate sounds of words and letters. Some experts believe that dyslexia occurs due to differences in the way the brain is structured, or functions. The brains of people with dyslexia may be attempting to process spoken and written language on the right side of the brain, while the brains of people who do not have dyslexia attempt to process language on the left side. Others believe that dyslexia occurs when the brain as a whole simply does not form properly, or that a combination of all of these factors might be responsible for dyslexia.
Some experts think that hearing impairment in very young children can cause them to suffer from dyslexia. The argument for this theory is that these young children mishear and misinterpret that sounds of language, and may have trouble matching letters to their correct sounds.
Others believe that problems with brain development or functioning are among the chief causes of dyslexia. Some researchers think that the brains of people with dyslexia simply don't form appropriately, so that the neural connections necessary for the normal comprehension of language aren't formed. Still others think that the brains of people with dyslexia attempt to interpret language on the right side of the brain. It is believed that the brains of normal people interpret language on the left side of the brain, so a person who uses his right brain to interpret language may be at a significant disadvantage.
It is believed that heredity is one of the primary causes of dyslexia. Researchers believe that a combination of genes may be involved in the development of this condition. It has further been found that the identical twins of people with this condition are usually very likely to suffer from it also. People who have dyslexia are usually very likely to have a parent, grandparent, aunt, uncle, or sibling with the disability. Many researchers concede, however, that the causes of dyslexia remain mysterious, and that some or all of these factors, as well as factors not yet identified, may be responsible for the condition.