Can't say for sure but I think the industry and time has a lot to do here. My father is a mechanical engineer who worked for a well known plastics company in th

Can't say for sure but I think the industry and time has a lot to do here. My father is a mechanical engineer who worked for a well known plastics company in the early 70s. He had a technical supervisor who started as a casual labourer at the same company.The supervisor couldn't write and used a thumbprint instead of a signature. However, he could interpret and analyse the designs for the moulds very well and was highly respected for that. It was the reason he was promoted to that level from that of a labourer. Perhaps his illiteracy was the reason he didn't rise any higher but the fact that the company was able to recognise his skill in a certain area and promote him to a level where it could be completely utilised says something about management philosophy. Equally, his ability to teach himself technical skills to be useful without a formal education says a lot about him too.