The autism spectrum disorders are highly heritable disorders. This means that it is very likely (over 90%) that the child of an autistic person will also be on the autism spectrum. The reason for this are certain genes. These genes are linked to autism and are passed on from a parent to the child. Already Leo Kanner and Hans Asperger noticed that fathers of autistic children often preferred being on their own over being with people. Therefore, Kanner and Asperger suspected a genetic cause. Studies with families with a child on the autism spectrum were done to investigate this theory. They found that sometimes the children’s parents (fathers as well as mothers) also show social difficulties, shyness and problems with understanding contextual information when talking to someone. Some studies have found this in only 10 out of 100 families, some in as much as 45 out of every 100 families.