More parents are happy with having an only child. Here's why

It's taken a long time for Claire Jackson to accept she doesn't have the "energetic or emotional capacity" to have a second baby.

The 39-year-old from Adelaide experienced a traumatic birth and postnatal mental health struggles. She's also managing a chronic illness.

"Going again" didn't feel like an option, says Claire, adding there was a lot of grief and shame connected to that realisation.

"Mainly the stuff tied to societal expectations of it being selfish not to give our son a sibling," she says.

But she and husband Josh have since realised family life with their two-and-a-half-year-old Brodie feels complete.

"Ultimately our dream is to live a life by design where we work less and travel more. All of this is made more doable when you don't double the headcount of kids.

The couple are among the increasing number of Australian families choosing to have just one child.

Although it's a more common family model, concerns only children will be "lonely and spoilt" persist, explains parenting educator and author Rosina McAlpine.

The stereotype stems from the belief that without siblings, children don't develop social skills, and the undivided attention and resources from their parents leads to indulgence.

But is a lack of competition for parental love and resources actually a good thing?

Why we're having fewer kids

In 1981, 7.6 per cent of women in Australia aged 40 to 44 only ever had one child. In 2021, that figure more than doubled to 16.3 per cent.

Dr Alpine says there are many reasons for this, including financial considerations, declining fertility, lack of village, uncertainty about the future, and personal preferences.

"In times gone by, society and your family would put a lot of pressure on you [to have more children]. Nowadays, people are more empowered to make their own choice," she says.

"There has also been an uptick in mental health and physical health problems, which makes it more challenging to have more children."

We also know that the motherhood penalty for women with one child is smaller than the penalty estimated for those with multiple children.

Where do only-child stereotypes stem from?

As one UK-based psychologist writes, psychology may be partly to blame for the stigma around only-borns.

Granville Stanley Hall, the first president of the American Psychological Association, said that "being an only child is a disease in itself".

Also influential was Alfred Adler, a prominent Austrian psychotherapist who described the only children he treated clinically in an extremely negative light.

More modern research means we now have evidence to the contrary, and yet, the idea that children "need a sibling" to be good and happy humans remains.

"In the industrialised world, the two-child family is widely thought to be ideal, with the three-child family being the next ideal," says Professor Toni Fablo from the University of Texas at Austin.

Professor Fablo is recognised as a leading expert on only children, having published 38 journal articles and chapters about sibling effects, examining these effects within child, adolescent, adult and elderly populations — including a six meta-analyses of 115 studies.

She has previously suggested parents of one child are seen negatively by people who have "suffered through the experience of bringing up several children".

What the research says about only-born children

Professor Fablo says the irony about the "loneliness" typecast is that only children are not lonelier than others, likely "because they are accustomed to being alone".

"People with siblings grow accustomed to the presence of siblings in the household and may actually feel lonelier when that sibling is not available," she says.

Her research has found only children rate higher than "all non-only children" in the "positivity of the parent-child relationship", as well as character traits like extroversion, maturity, cooperativeness, autonomy and leadership.

A study from 2019 found only children are no more likely to be narcissistic.

So when it comes to sociability and character, studies indicate only children are no worse off than those with siblings — and in some cases better off.

In terms of intelligence, research from September this year found "when looking at how children performed in cognitive tests, only children tend to be similar to children growing up with one sibling", adding that family socio-economic status and parents' relationship played a more significant role "than whether they have brothers or sisters".

What really matters

Dr McAlpine says it's useful to look at research, but what really matters is the relationship between the parent or parents, and child or children.

She's worked with thousands of families and says a "strong bond" is the heart of success or failure when it comes to the health and wellbeing of children and their caregivers.

"I always talk about the heart and science of parenting," Dr McAlpine says.

"When you want to make an informed decision, you want all the information.

"But we need to combine that research with what we know from others, and what fits in with our own family."

Claire says she hopes society can move away from commenting on family size.

"A bit like we don't assume that people want a family, people stop asking when we will have another child.

"Family size isn't always a choice, and even if it is, variety is the spice of life."