As if we didn't know

The Social Mobility and Child Poverty Commission found less able, richer children were 35% more likely to become high earners than brighter, poorer peers. 

Wealthier families helped their children accumulate skills valued by the labour market and they also used social networks to secure internships and employment. That meant poorer, but more able children were often blocked from the finite number of top jobs. The report also highlighted a "private school wage premium", where recruitment to high-earning occupations is biased towards those educated in private schools.

The research suggests there is a clear correlation between the social background of a child's grandfather and eventual labour market success.