It is nearly 50 years since Fianna Fáil minister for education Donogh O’Malley announced plans for free second-level education for every child up to intermediate level.

These reforms opened up education for the children of manual labourers, thereby helping a generation to take advantage of the economic and industrial expansion of the 1970s.

All these years later, we might expect that the availability of free, high-quality education for all in Ireland would mean that family income no longer matters for educational success.

If schooling is free and available to everyone, surely this means that educational success is simply down to your innate ability and how hard you work?

Well, the proportion of young people going on to higher education has certainly increased.

University used to be for the privileged few. By 1980, however, about a fifth of school leavers were attending, and by the late noughties more than half of all school leavers were making the transition into higher education.

Yet research by the Economic and Social Research Institute shows pronounced inequalities between groups: although more than 60 per cent of school leavers from professional families will go on to third level, less than 40 per cent of their peers from semi- and unskilled manual households will.

ESRI research also suggests some reasons why this happens.

First, young people from semi- and unskilled manual groups do worse at their Leaving cert. The children of professionals are 250 per cent more likely to earn two or more Leaving Cert “honours” (grades A, B or C on a higher level paper) that will grant them entry to a third-level course.

Second, even if their children get the requisite exams, young people and parents in working-class households are less likely to choose to go to college.

University experience

Again the ESRI has looked at this. It suggests that less knowledge and experience of universities among working-class parents and worse career guidance in working-class schools are the prime reasons.

But why do working-class children do worse in school? Here there seems to be far less agreement. Evidence suggests that they display less ability in school and, from the end of primary school on, can become estranged from teachers and the educational system.

Some argue that working-class “culture” might be to blame here: maybe working-class parents don’t value traditional education as much as middle-class parents do.

Others have focused on the transmission of what is termed “cultural capital”: the cultural knowledge and interpersonal skills among middle-class families. To some extent, this seems to be true.

Research shows different styles of parenting across groups when it comes to how parents talk to and spend time with their children. Getting children to explain their needs and emotions, and providing reasons for decisions, cultivate greater confidence around authority, plus better language and social skills among middle- class children.

Still, my own research suggests something else might actually be going on – something we should be paying more attention to.

Using data from the Growing Up in Ireland study, along with evidence from British cohort studies, it is clear that some of the more challenging classroom behaviours and lower ability of many working-class children have their roots in the resources available to these families.

Lower income means fewer stimulating experiences, fewer books and learning opportunities, even when we adjust for the parents’ own level of education.

But lower income also has indirect effects on children’s learning. With lower income comes more economic strain for parents – and, with this, more psychological distress and depression. Both of these are toxic to good parenting.

Using data from 2008 to 2010, research with colleagues from the ESRI and from TCD demonstrates the way that economic recession influences parental mental health and patterns of parenting. Even well-educated, professional parents become harsher, more inconsistent and more distant when put under psychological strain.

Understandably, children then receive less of the stimulation that promotes learning. They also react to their parents’ distress with worse behaviour of their own at home and in the classroom.

No escape

Ireland’s economic meltdown has made this experience more widespread in recent years, but for many the low income doesn’t go away when the economy picks up.

We all have our ups and downs, and children’s behaviour will usually recover when the crisis is over.

The problem is, even employment no longer guarantees escape from low wages and economic strain.

For many families, the end of “the crisis” won’t mean the end of money worries. So the likelihood is that we will continue to see more educational success in some groups than others.

• Richard Layte is professor of sociology at Trinity College Dublin and a research professor at the ESRI