I think you would be very suprised then suwoo
Many families home educate without any A levels or higher.
There are a couple of interesting pieces of research you might want to look at.
Rothermel in 2002 found:
"The results show that 64% of the home-educated Reception aged children scored over 75% on their PIPS Baseline Assessments as opposed to 5.1% of children nationally. The National Literacy Project (Years 1,3,5) assessment results reveal that 80.4% of the home-educated children scored within the top 16% band (of a normal distribution bell curve), whilst 77.4% of the PIPS Year 2 home-educated cohort scored similarly. Results from the psychosocial instruments confirm the home-educated children were socially adept and without behavioural problems. Overall, the home-educated children demonstrated high levels of attainment and good social skills."
yet
"Socio-economic class is not an indicator of achievement levels: whilst the home-educated children outscored their school counterparts, those from lower socio-economic groups outperformed their middle class peers. Figures indicate that at least 14% of the parents in the home-education sample were employed in manual and unskilled occupations."
and
"In this study, parental level of education did not limit the children's attainment. At least 38% of parents in this study had been educated at comprehensive schools and at least 21% had no post-school qualifications. Whilst 47.5% of parents had attended university, at least 27.7% of parents in the study had not."
and in 2007 The Frasier Institute in Canada found:
"Home schooling appears to improve the academic performance of children from families with low levels of education, according to a report on home schooling"
"The evidence is particularly interesting for students who traditionally fall through the cracks in the public system," said Claudia Hepburn, co-author of Home Schooling: From the Extreme to the Mainstream, 2nd edition and Director of Education Policy with The Fraser Institute.
"Poorly educated parents who choose to teach their children at home produce better academic results for their children than public schools do. One study we reviewed found that students taught at home by mothers who never finished high school scored a full 55 percentage points higher than public school students from families with comparable education levels."