Existing evidence indicates that it is hereditary. The probability of dyslexia has been traced through several generations of many families. Since dyslexia frequently goes undiagnosed even today, it isn't always possible to secure clinical proof. However, it is not unusual to discover a father, uncle or other living relatives who have the problem to some degree. A. Spotty performance on tests.
Achievement is high in some areas, low in others.
Impaired orientation in time. Impaired discrimination of right and left. Even some adult dyslexics have to mark their hands to tell left from right. In a remediation class, the teacher asked her 6 pupils to raise their right hands, then turned her back and raised her own right hand to illustrate the request. When she turned back around, the two children on the right had raised their right hands, the two on the left their left hands, and the two in the middle had raised both hands.