When teaching handwriting, one difficulty is teaching the left-handed child. The traditional policy has been to push all children to write with their right hands. Parents and teachers both try to prevent the child from using his left hand. On the other hand, psychologists have clearly shown that some persons are naturally left-handed and that it is much more difficult for them to do any skillful act with the right hand than with the left hand. Some believe, furthermore, that to force a left-handed child to write with his right hand may make him nervous and may cause speech problems. There seems to be some cases in which this is true, although in most children who change over to using their right hand, no negative effects are noticed. In addition to these difficulties, left-handedness sometimes seems to cause mirror writing from right to left and reversals in reading, as reading "was" for "saw." The traditional policy in teaching handwriting has （）.