‘Two years and three months is the best age gap between siblings’
Brothers and sisters of a similar age often do less well at school, but will have a close relationship, writes Genevieve Roberts
When I was trying to get pregnant with my son Xavi, going through successive rounds of fertility treatment, I remember feeling huge time pressure to conceive quickly so there would be a narrow age gap between him and his older sister Astrid.
I focused my fertility stress on the lengthening passage of time between children: would they even have anything in common with an extra 30 days of unshared experience?
After many failed attempts over six months of trying, I became pregnant, thereby creating a two-year and one-month age gap between Astrid, who is now six, and Xavi, four.
This is close to the average gap between siblings in the UK – two years and four months, according to census data from 2020, down from an average three years in 1953, partly because women are having children later so have fewer fertile years left.
Many parents fret over achieving the “ideal” age gap between their children – so what is it? Some studies have shown that closely spaced siblings do less well academically because they compete for time with their parents – though they are more likely to have a close relationship.
Dr Cara Goodwin, a child psychologist and bestselling author who has analysed dozens of academic studies, suggests that for parents at least, it is somewhere between two years and three months and two years and eight months.
“Really, it’s a decision for each family to make individually, to find the ideal for them. The research is all correlational, so it’s hard to make firm conclusions,” she caveats, adding that academic research didn’t determine her own family planning.
“But health research suggests that with a smaller age gap [than this] the woman’s body is depleted from their previous pregnancy and with a wider gap the body has returned to a pre-pregnancy state and it’s harder to go back.”
Health benefits did not cross my mind when trying to conceive any of my children, but – and I appreciate that this might sound counter-intuitive – I did find a narrower age gap easier on my mental health.
When Xavi arrived, I already took sleepless nights for granted and my sense of identity was deeply buried under nappy changes. By contrast, the threeand-a-half-year gap between Xavi and my third child, Juno, had allowed me time to rediscover sleep, and my sense of self,
however fragile. I imagined that feeling of losing and re-finding yourself might be even stronger for my cousin Emma, who lives in Edinburgh. She also has three children, but with far wider age gaps: Rufus is 15, Matilda is 10 and her youngest, Hamish, is two.
“Having older kids slightly dilutes it, we’re simultaneously meeting different needs,” says Emma. “I don’t think I could have condensed those 15 years: Rufus and Matilda are both better ‘parents’ than me – and definitely have an interesting playmate/ parent hybrid role.”
Having older children also brings a sense of perspective. “I’m much more relaxed,” she says.
One striking difference that Emma has noticed in her two-year-old, who was playing hockey with his older sister while we chatted, is his race to learn.
“Hamish’s language development is incredible. He has four ‘grown-ups’ speaking to him and is keen to keep up,” she explains. “He’s recognising many alphabet letters and starting to grasp sounds. Full credit to his big brother and sister. On the flip side, he’s realised he gets a rewarding reaction if he says: ‘f**k it’.”
Her observation is backed by research which shows a sibling gap narrower than two years is academically negative.
“Closely spaced siblings are less likely to complete high school and attend college,” Dr Goodwin explains. Research suggests that this is true of both, or all, siblings, in a correlational study so age of marriage, breastfeeding and socioeconomic status could all have some influence.
“One reason for this could be that when parents have children close together they have less time to spend talking, interacting and reading with each child, which could impact on academic outcomes,” says Dr Michele McDowell, a child psychologist.
This is also believed to be at least part of the explanation for why wider age gaps are associated with “increased IQ scores and better educational outcomes for reading and maths”.
Dr McDowell adds: “The younger sibling has enhanced language skills, which is probably because the younger sibling has more exposure to language and has a model for regular language interaction and therefore is more likely to develop language skills efficiently.”
Mostly, when having children, I imagined them playing together and I love seeing Astrid, Xavi and Juno chase each other around our lounge, or play imaginative games.
Juno – who is oblivious to the sometimes competition for the alpha role among her elder siblings – is immune from any fighting. Partly, that’s her age but I also sense that Astrid feels protective rather than challenged by someone five years younger.
Dr Goodwin, who has four children whose ages range from eight to seven months, says that children close in age tend to be close, but the trade-off is sibling rivalry.
“They tend to fight more – I can back that up with personal experience – and see each other more as rivals. Wider gaps of four or more years often lead to greater affection, while with less than four years they are more likely to be close,” she says.
Of course, Astrid, Xavi and Juno are close – whether playing or fighting. It seems almost laughable that I once wondered whether a month or two would make a difference to their relationships when now all I feel is fortunate to spend my life with three, wonderful, healthy children.
As my almost-niece Matilda says: “Even though we say our siblings are annoying, inside it’s the opposite. Inside, we care for them and don’t want to hurt them.”
Children close in age tend to be close, but the trade-off is a sibling rivalry