Since I am pregnant with my second child – a boy! – there is only one detail that has been bothering me: the age difference. My firstborn will be six Years older than my newborn, which feels light years ahead developmentally. Will they still fight over toys? Fight for their parents’ attention? Maintain a close bond? These are just some of the Care for Questions are buzzing through my head.
That’s when I came across a new and surprising study: According to a 2020 study that analyzed fertility rates in modern times, larger age gaps between siblings are becoming more common. This, in turn, could change family dynamics (and birth order)—and not in a bad way.
First, a quick look at the data: Between 1967 and 2017, the gap between births of siblings widened only minimally—about three-quarters of a year. By comparison, today 22 percent of mothers have their children six or more years apart, according to the study. Research shows that siblings are still about four years apart on average, but today’s fertility resources (not to mention a changing definition of the American family since the 1960s) are causing that gap to widen more quickly.
For example, couples who want children now have access to contraception (which means they have more control over planning their pregnancies), and there are services such as IVF that can help extend the childbearing window and ease the difficult road to fertility. Added to this are changing family dynamics. Life experiences such as divorce and remarriage (also known as multi-partner fertility) are other factors that can also lead to a larger age gap between siblings.
In addition, the birth rate is declining for a number of reasons: women are waiting longer to have children and are also choosing to have fewer children. (I’ll briefly touch on the lack of support for working parents here.) Whatever the reason, if you’re not planning on having five babies, that’s another factor that reduces the rush to have them one at a time.
But now to the bigger question, which goes back to my original concern: If age differences Are What impact will this have on sibling relationships and children’s personalities in the future?
To find out, I consulted Dr. Laurie Kramer, a licensed clinical psychologist and professor of applied psychology at Northeastern University, where she directs the Siblings Research Group. (She is also founding director of the Family Resiliency Center at the University of Illinois.)
The benefits of a growing age difference between siblings
She explains that it really comes down to parental resources. “Think of a six-year-old who has his or her first sibling and has had six years of undivided attention from his or her parents, grandparents and others. When the child was just born, the parents were also excited and attentive and tried very hard to understand and meet the child’s needs. With only one child, they have the luxury of doing that.” When a sibling comes along – or four – everything changes, Dr. Kramer continues. In other words, attention is divided.
A larger age gap, however, can soften that blow. A larger gap means parents likely have more on their hands—everything from time to patience to money. Yes, this massive change in family dynamics is tough, but it’s happening alongside an older child who has likely already developed a whole host of social and emotional skills that Dr. Kramer says are critical when it comes to forming a positive bond with another child, especially a sibling. “Parents with children who have a larger age gap can capitalize on that developmental maturity, which will ultimately really help the child cognitively grasp what’s going on.” (Something like “We’re having another child, that’s so great, we’re still going to love you,” for example, is easier for a six-year-old to process than a toddler.)
This means there is a greater likelihood of what Dr. Kramer calls perspective taking. “The older child may be smarter when trying to interpret a newborn’s wants or needs,” she explains. “And when he becomes suspicious about things like, ‘How will my parents continue to meet my needs and do the same for this newborn?’ he has the cognitive and language skills to express his feelings in a way that is accurate and not irrational.” In other words, fewer tantrums, more talking – all of these can improve the budding relationship between brother and sister.
The disadvantages of a larger age difference
But that doesn’t mean there won’t be unique challenges. A larger age gap will likely mean differing interests, and for parents who need time-saving options (like an after-school activity together), a larger age gap will mean those won’t align. For an older child who can continue with their normal, typical activities – things like school and friendships outside of the family – this may not be such a life-changing change, but it could also weaken the bond between the older child and the baby.
Does this mean that birth order theories (such as eldest daughter syndrome or risk-taking by the youngest) no longer hold? Dr. Kramer is clear that this is a new trend and the long-term effects are still being studied, but this trend certainly has the potential to turn what we know on its head.
How to influence sibling dynamics
Dr. Kramer says the people who really call the shots when it comes to sibling dynamics and development are—surprise—the parents. “The most important question parents have to ask themselves when raising siblings is, ‘What kind of relationship do I want my child to have with each other?'” she says. The bigger the age difference, the more effort is needed to bridge the gap. “Again, parents with an older child have the advantage of being able to really talk to their older child and be more sensitive to their needs and have bigger conversations.” They can nurture and structure the connection rather than constantly trying to resolve conflict (e.g., mediate arguments and more). But extra effort needs to be made to point out commonalities and help children find shared interests and ideas, she adds.
No pressure, mom and dad.
Oldest? Youngest? Middle? What your birth order says about your personality
