When Michael's* 10-year-old son was diagnosed with Asperger syndrome, he researched it and made an unexpected discovery.
His investigation provided a key to his own father's behaviour. His Dad displayed some hallmark characteristics of the condition.
"My son is a more classic example of Asperger's but my father had enough traits to put him on the autistic continuum," says Michael, now in his early 50s, who says he also has some Asperger's characteristics.
When he was growing up, he recalls, his Dad was exceptionally strict and very rule-bound.
"He was quite inflexible and very fussy in his habits and very dependent on routine. He could be very ritualistic -- things in the house had to be done in a certain way.
"He was quite autocratic and odd and that irritated me, particularly the way he discounted other people's views.
"He was also quite controlling, which annoyed me immensely as a teenager.
"He could seem rude -- he wasn't a person given to casual chat and it wasn't easy to have a casual conversation with him."
Although his father was affectionate towards his children, he had no mates.
"He had no friends. He wasn't the type of person who'd go out for a drink with a friend, and as a child I often wondered about this.
"The lack of a perceived need in a person for friendship is a very big characteristic of the condition."
His father also had a very strong interest in opera -- an abiding interest in one particular subject is another Asperger's trait.
Yet, although he had an encyclopaedic knowledge of the subject he refused to attend concerts as he disliked big social gatherings or crowded rooms.
*Not his real name
A person with Asperger syndrome may:
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