Better educated parents have children who are more relaxed, outgoing and explorative

Exactly how parents shape their children is a matter of controversy, especially since Judith Rich Harris' book The Nurture Assumption popularised the behavioural genetics position that the "shared environment" (so-called because it's shared by siblings) – including the family home and parents' methods of upbringing – has scant influence on how children turn out. But the debate is far from settled, and now a team chiefly from Florida State University has investigated whether more educated parents produce offspring with particular personality characteristics. Published in the Journal of Personality and Social Psychology, the research identifies a number of personality differences that correlate with parental education, and the researchers suggest the causes of this association must be more than just genetics.

The study, led by Angelina Sutin, is the largest and most focused investigation of personality and parental education to date, drawing from seven surveys, one of students and the rest wide-scale public surveys, for a total of over 60,0000 surveyants. The data included personality measures (these differed per study, but all mapped directly on to the so-called Big Five traits), and the years spent in education by each parent.

The evidence showed that child personality was associated with parents' levels of education. More educated parents were more likely to have offspring who scored higher in trait Openness to Experience across almost every survey, and in the bulk of the samples more education was also associated with higher Extraversion and lower Neuroticism. A way to integrate and make sense of these three associations is that children of the more highly educated are more relaxed, outgoing and explorative; they are oriented to approaching the world rather than avoiding it.

The links between parental education and children's personality were mediated by three factors that also give some insight into the reasons behind it all. First, parental education was associated more strongly with kids' personality in families where the kids were also more highly educated. An obvious explanation for this finding would be that children's personality is shaped by their own more intense education, however, previous research has found only weak evidence for this. It seems to me an alternative, if partial, explanation is that greater parental education usually has a beneficial effect on a child's personality, but when a child withdraws from education much earlier than their parents – deviating from a script – this may indicate that they have more turmoil in their life, either as a cause or consequence of their educational decisions, and this may disrupt the personality benefits otherwise bestowed by an educated parent.

As the children of the more educated grew older they showed even more pronounced increases in Openness and Extraversion and a drop in Neuroticism.

A second mediating factor was children's IQ in adolescence. That is, greater parental education correlated with their children having higher IQ in adolescence, and in turn, higher adolescent IQ correlated with higher Openness and Extraversion and lower Neuroticism. We already know that higher IQ leads to better executive functioning, and the adoption of better coping strategies in response to stress, so these could contribute to personality traits that indicate greater confidence to address the world and handle problems. And in principle, parents' education could benefit their children's IQ in adolescence due to factors like an enriched environment earlier in development, or differential levels of nutrition or disease.

The third mediating variable was effect was familial income. Parental education was more strongly associated with children's personality when the parents were richer. So it may be that the association is partly due to the fact that more educated parents tend to have wealthier families, giving their children a financial cushion against risk and stress, and providing more opportunities and experiences to broaden the mind and cultivate engagement in the world. But as with the other mediators, wealth didn't fully explain the results.

But we need to take stock and consider the elephant in the room: the genetic explanation. The observed associations between parental education and children's personality (and the mediating factors) could all be explained by a gene complex passed between parent and child that shapes intelligence and personality in parent and child, and that encourages the pursuit of education, and facilitates higher lifetime income through the generations.

To test this possibility, Sutin and her colleagues traced 545 people in the surveys who were raised by adoptive parents, people for whom we should not expect to see these personality differences if they were due purely to genetics. But the adoptees showed personality associations with parental education that were similar and in some cases stronger than in the main group – such as (adopted) maternal education having a significantly greater association with Openness. This means that genetics cannot be the driving explanation for these associations, which adds to a corpus of recent research that challenges the behavioural genetic consensus on the irrelevance of the "shared environment" to fundamental psychological traits like personality.

Intriguingly, there was also a beneficial developmental turn to the observed patterns. As the children of the more educated grew older – and many surveys provided data on these children beyond middle age and even into their nineties – they showed even more pronounced increases in Openness and Extraversion and a drop in Neuroticism, relative to children of the less educated. Summoning a comparison to the "cognitive reserve" – the notion that some people seem to maintain good mental functioning into older age even when suffering from neuropathology – Sutin's team suggest that parents' education may be bestowing a "personality reserve" in their children that helps them to resist the turn away from exploration that aging encourages.

This study doesn't indicate a single definitive mechanism to explain why parental education is linked with children's personality, and it's likely that there are even more processes at that the researchers didn't look into, such as the known association between lower Neuroticism / higher Openness and breastfeeding, an activity more common in more educated mothers. It seems likely that greater parental education provides their children with a constellation of benefits. And while there may be a genetic contribution, the adoption data suggests that the environment provided by educated parents may itself be shaping their children's personality development. Identifying "always nurture" as a misleading assumption was an important step forward in psychology; for progress to continue, it looks like "never nurture" also needs to be consigned to history.