According to the National Research Council, Preventing Reading Difficulties in Young Children (1998), "academic success, as defined by high school graduation, can be predicted with reasonable accuracy by knowing someone's reading skill at the end of third grade. A person who is not at least a modest skilled reader by that time is unlikely to graduate from high school."
In order to effectively teach children how to read, we must understand--at some level--the process which the brain goes through in order to read. The video below provides a look into the function of the brain, as it relates to reading.