Do you happen to have any studies to back this up? It makes sense that parental wealth would be one of the strongest predictors of wealth, but I know of at least one study that has demonstrated that 79% of millionaires did not receive any inheritance from their parents.
The prediction does not hinge on inheritance (most folks manage to start their own lives, careers and families well before their parents pass), but on the upbringing, milieu and economic as well as social capital available.
"You're likely to stay in the social class you were born into" - is basically what the predictor means.
"You're likely to stay in the social class you were born into" - is basically what the predictor means.