Are we born leaders?

How your siblings – or lack of them – has shaped the skills you need at work.

Glen Allsopp first came up with the brilliant idea for his business sat in his childhood bedroom at home in Newcastle, aged 16. Its rapid success led him to relocate from the UK to Cape Town before he even reached adulthood.

But where does such striking entrepreneurial spirit come from? Genes, parenting and education all likely play a role, but how does your family – especially your brothers and sisters – shape you?

Allsopp, the 30-year-old founder and CEO of detailed.com (an SEO consultancy that's worked with eight and nine-figure companies), is the youngest of three siblings, and he credits his position in the family with giving him the freedom to be creative and take risks.

“I could see my parents become more open to their kids doing different things as we all went from school and into the job market,” he says. “I had total freedom to quit my part-time job, leave college and essentially start a new life on a different continent.” 

The idea that last-borns are more adventurous is just one of several theories swirling around the research literature on how our position in the family affects us in ways that play out in our adult careers. An even more popular idea – an almost taken-for-granted fact – is that first-born children, with their years of experience as top dog, are more disposed to become leaders.

Yet the scientific evidence for this is weak at best – some experts even describe the influence of birth order on personality as a “zombie theory”, i.e. one that refuses to die despite being refuted.

But that doesn’t mean our sibling relationships (or lack of them) have no impact. Recent findings suggest that instead it may be the age gap between siblings, the balance of boys and girls, and quality of the sibling relationships that matter more.

Those squabbles over who rides in the front of the car or who gets the latest bedtime may in fact be transformative. The battles and diplomacy of sibling life really can help equip us with the kinds of personal skills and attributes we’ll find useful as working adults.

Born to lead?

In terms of how our siblings shape us, it’s definitely our position in the family – birth order – that’s the hot topic. The internet is littered with dramatic articles claiming first-borns are more likely to become leaders.

Why wouldn’t first-borns take those family boss skills and instincts forward into their working lives? There’s plenty of anecdotal support for the idea too: European leaders Angela Merkel and Emmanuel Macron, for instance, are both first-borns, as are the recent US Presidents Bill Clinton, George W Bush and Barack Obama (or raised as such – Obama had older half-siblings who he didn’t live with). In the world of business, Sheryl Sandberg, Marissa Mayer, Jeff Bezos, Elon Musk and Richard Branson, to name just a few famous CEOs, are all first-borns.

And yet several studies have debunked the notion that birth order profoundly shapes our personalities. They analysed whether, for instance, we turn out more conscientious versus idle, or dominant versus timid.

In 2015, two huge studies found no meaningful association between birth order and personality traits. In one, Rodica Damian and Brent Roberts at the University of Illinois at Urbana-Champaign assessed the traits, IQ and birth order of nearly 400,000 US secondary-school students. In the other, Julia Rohrer at the University of Leipzig and her colleagues assessed IQ, personality and birth-order data from nearly 20,000 people in the UK, US and Germany. In both studies there were some small correlations but they were minuscule in terms of their practical relevance.

Another popular idea related to birth order is that last-borns, like Allsopp, are more inclined to take risks – yet this specific claim was also debunked when Tomás Lejarraga at the University of the Balearic Islands, together with colleagues, found no meaningful association between adventurousness and birth-order position.

Liking your siblings helps

So, birth order may not be all it’s cracked up to be. And yet watching a pair of siblings play and fight, argue and make friends again, it seems incredible to think that these experiences would not leave their mark. One thing to bear in mind here is that birth order is only one aspect of sibling dynamics.

The lack of a first-born or last-born effect doesn’t mean that your individual experience in the family hierarchy didn’t shape the person you’ve become.

It may be the particular nature of your own relationships and role in the power structure that matter. But caution is again required – as Rohrer points out, if you find a link between sibling relationships and behaviour later in life, there is a much simpler explanation: the stability of personality. “Somebody who takes care of their siblings might simply be a very caring person, and also act caring later in other environments; without any actual causal effect of sibling relationships,” she says.

Aside from these nuances, there is some evidence that sibling relations can have far-reaching psychological consequences. Above all, the quality of the sibling dynamic seems crucial – siblings can either cause or protect against mental health problems depending on whether there is warmth or conflict between them.

The gender of our siblings might also make a difference in ways that matter for our later careers, with one study finding that men with older sisters were less competitive – although again it’s important not to exaggerate the practical size of this effect.

Another specific factor that might be more consistently relevant than birth order is whether you had a sibling close in age to you. A recent study of more than 4,000 Brits found people who were closer in age to their older sibling tended to be more outgoing and less neurotic – presumably because they got to compete on a more level playing field for their parents’ attention, and were more likely to play and learn from one another.

Earlier research found siblings who engaged in more pretend play together also tended to have a more precocious understanding of other people’s emotions.

It’s also worth remembering that brother and sister relationships do not exist in a vacuum – siblings tend to enjoy better relations where they are raised in a more organised home environment with parents who are happy together. In other words, there’s a nesting of effects – yes, your relationship with your sibling might have affected your own development, but in turn your dynamic with your siblings might have been shaped by the broader atmosphere at home.

The power of one

Being emotionally resilient, empathic and socially skilled are obvious advantages in many careers (as is being more of an extrovert in professions like sales, teaching or journalism). In this context, the research suggests having a sibling who you get along with may provide the perfect training ground. So where does that leave only children like me or Brendan Hufford, an SEO director at design agency Clique Studios? Hufford says the experience of being an only child influenced him deeply.

“I've noticed that I seek a lot of outside validation,” he says. “Without siblings to validate my daily experiences growing up, I looked to others to provide input on my work and daily events.” He says that in his professional career, this has really helped him engage with colleagues and build a rapport quickly. “However, as I moved into leadership positions, the number of colleagues that I could share openly with was reduced, leading to long periods of ambivalence regarding my ability and effectiveness as a leader.”

In terms of the research literature in this area, some of it is rather disconcerting: for instance a study that compared the personality traits and behavioural tendencies of people born in China just before or after it introduced its one-child policy found that those in the latter group – predominantly only children – tended to be “less trusting, less trustworthy, more risk-averse, less competitive, more pessimistic and less conscientious”. Not a great profile for success navigating office politics later in life.

“I've had to work on learning to listen and give my teammates time to process things,” says Hufford. “As a natural questioner, I've already thought through concepts very deeply before presenting them and, as an only child, I never had any competing interests other than convincing my parents of something. Compromise and communication was minimised to only what most affected me.”

Another recent study revealed related results in terms of the possible social consequences of being an only child – participants who were only children scored lower for “agreeableness” (they were less friendly and trusting). However, there was a silver lining: the only children in the study performed better in a test of their creativity, a finding that the researchers put down to their having received greater attention from their parents and/or the fact their parents expected more of them. (I would add that perhaps only children also benefit from more time spent alone with their imagination.)

That last result is tentative for now. But it suggests that, while I (and other only children) might wonder what it would have been like to have brothers or sisters to chat and play with, perhaps the quiet I enjoyed at home helped lay the foundation for becoming a writer. After all, whatever our formative family experiences, there are many different occupational niches we may be able to flourish in.

Images produced by Javier Hirschfeld

Dr Christian Jarrett is a senior editor at Aeon magazine on their forthcoming Psyche channel devoted to psychological wellbeing. His next book, about personality change, will be published in 2020.