Like father, like son? The complex factors that shape a parent’s influence on their child

Al Pacino and Marlon Brando‘s father-son relationship in The Godfather was complicated, to say the least. Photograph: Pictorial Press Ltd/Alamy

The eternal mystery of how much we are shaped by our parents – or how much we shape our children – was stirred again last week with the publication of a study that suggests that we are less like our parents than we had previously thought.

Led by René Mõttus of Edinburgh University’s department of psychology, the study looked at more than 1,000 pairs of relatives to establish how likely children are to inherit what psychologists call the “big five” or “Ocean” personality traits: openness, conscientiousness, extraversion, agreeableness and neuroticism.

According to the study, the chance of a child sharing a similar personality trait with a parent is not that much greater than of the child sharing it with a random stranger. Say, for example, that the general population is divided equally into thirds between those who have low, middle and high levels of openness. The study suggests that only 39% of children will be placed in the same category as a parent, compared to 33% with a random stranger.

The novelty of this study is that instead of relying solely on self-reporting of personality traits, it also includes the second opinion of a friend or partner. But the paper has yet to be peer-reviewed and has already been criticised by one leading expert in the field.

Robert Plomin, professor of behavioural genetics at King’s College, London, questions why other people’s opinions about us should be seen as more accurate than our own.

“I don’t buy it,” he says, “where’s the evidence?”

He also has a number of other reservations about the study. Ultimately, he says, “the paper seems bloated, both in terms of length and hyperbole”.

Plomin published a book six years ago called Blueprint: How DNA Makes Us Who We Are, arguing that, as a result of polygenic testing, it was possible to see that our genetic inheritance played a much greater role in determining our behaviour and personality traits than science had previously allowed.

Plomin has his own critics, not least in regard to his suggestion that a person’s socioeconomic status might be a genetic rather than environmental legacy. While science continues to grapple with the data and different interpretations are contested, the rest of us struggle to make sense of ourselves in terms of the families we came from and the families we create.

These issues frequently arise in the consulting room of Jennifer Cawley, a psychotherapist. “People don’t tend to talk about personality traits,” says Cawley. “It’s more about experiences and relationships, which I suppose is personality in context.”

She finds that many clients fear becoming their parents, particularly when they have children themselves. “If they had an experience with a parent who routinely lost their temper, then a lot of energy goes into trying to avoid repeating those patterns – replicating the expression of that personality trait, if you like.”

She sees this especially with men who have had abusive fathers. Of course, it’s difficult to know whether a tendency towards anger is a learned or genetically inherited trait. Even someone like Plomin, who has been called a genetic determinist, emphasises that we don’t inherit personality traits so much as a predisposition towards them. Whether, how and when those predispositions materialise is down to a whole range of complex and perhaps unknowable factors.

Whatever the cause, the influence of fathers, both absent and present, has been an abiding theme of fiction from Oedipus through to The Godfather. The journalist and writer Sam Miller knows more than most about present and absent fathers. Aged 15, Miller learned that his biological father was not the celebrated academic and literary critic Karl Miller, who had raised him, but instead his parents’ deceased university friend, Tony White, who had had an affair with Miller’s mother.

Miller wrote a poignantly reflective book, entitled Fathers, about the differing roles these two men played in his life. Although the initial revelation came as a surprise, it didn’t affect Miller’s relationship with the man he saw and continues to see as his father – Karl Miller, who died in 2014. The book is in part a moving tribute to someone with whom he shared so much, with the notable exception of DNA.

Partly due to his close relationship with Miller senior, Miller was for a long time largely incurious about White. But in recent years, he says, “I have wondered more about him, partly because in certain ways I’ve become more like my biological father.”

While Miller senior was effectively an orphan who made a stable family life that was very important to him, White, paradoxically, came from a loving family and grew up to lead a single, peripatetic life.

Miller explains that he himself was married with two children, but is now single and a roving foreign reporter.

“What’s odd,” he laughs, “is that I had 20 years of being my dad as a grownup. Now I’m having my 20 years of being a Tony! It’s quite funny, but I veer away from genetic explanations as sort of hard to prove and almost overly romantic. But I’m struck by the fact that I can’t explain things with my own children except as some kind of inheritance.”

A further complication for Miller is that he thinks his father and his biological father “were quite similar”. They both, for example, were deeply interested in writing, as is Miller himself. “I think in some ways they were each other’s alter ego.”

In such circumstances, it’s impossible to disentangle genes from environment, biology from culture, and the person we are from the person we were always going to be. Science may be growing inexorably closer to solving the riddle of our genetic inheritance, but what we do with it and why will remain questions for which there can be no irrefutable answers.