Not only the educational level of the parents positively influences the academic results of the children: also that of their family .
This is what this study that analyzes four generations in Sweden suggests, the results of which support this hypothesis.
Schooling and grades
As we can see in the following graph (horizontal axis are years of schooling and vertical axis with the effect on the average of grades in the last year of compulsory schooling), if the parents study more than the average, the grades are better ( black line). But the effect is more significant if we also assess the educational levels of other relatives , such as uncles or cousins (green, yellow and blue lines).

In other words: studying not only improves the individual, but also your environment, even other different generations. The problem is that perhaps those who are already born in a family where there are few studies, such individuals are born with that handicap, thus entering a kind of negative family feedback.
Be that as it may, this kind of analysis is important and necessary to clarify all the variables that come into play when the social elevator works or not, that is, that people, through their own merits, can really overcome your social class or not being trapped forever in it .