Study finds childless people may blame their GENES for being less likely to want a family
- Genetic variations may explain why some people remain childless, scientists say
- They don’t make people infertile, but they can make them less likely to want a child.
- People with this genetic profile tend to earn less and are less likely to have advanced degrees.
- But scientists say life choices play a much more important role in childlessness.
A new study has found that a small number of childless people have genetic variations that may make them less likely to start a family.
The researchers say these devastating mutations don’t make people infertile, but they may increase their desire to stay single and never have children.
People with this genetic profile also tend to earn less and are less likely to graduate, according to a study by the Wellcome Sanger Institute near Cambridge.
Experts say this could help explain what’s going on, but much more research is needed to find out why some childless people are less likely to want to start a family, for example, when looking at personality traits.
A small number of childless people have genetic variations that may make them less likely to start a family, new study finds (image)
Why do women delay having children?
The explosion of opportunity for women born in the 1970s and 80s has led to a decline, experts say.
They are more likely to go to university and continue their careers before settling down than previous generations.
Polls show that financial pressure has left women feeling they cannot afford to have a child in their 20s.
Rising childbearing costs, job insecurity and housing factors are also believed to have contributed to the sharp decline in new mothers.
Fertility experts warn women that the risk of not being able to conceive increases as they wait until their 30s.
But proponents say the health service has to adjust to the changing habits of modern mothers.
They also stressed that their results only explain a small proportion of childless people, and that life choices play a much more important role.
Even for those with the most genetic variation associated with childlessness, the chance of having a child is about 50/50.
Some genes cannot stand destructive genetic variation, which leads to their removal from the population by natural selection.
Previous research, which focused on a subset of approximately 3,000 loss-of-function genes, found that mutations in some of these genes may be associated with reduced offspring.
For example, mutations can cause disorders that shorten lifespan, lead to infertility, or affect cognition or behavior. However, about two-thirds of known restricted genes are not associated with such genetic diseases.
To explore how natural selection might affect the 3,000 or so limited genes previously studied, Matthew Hurles and colleagues analyzed data from 340,925 British Biobank participants aged 39 to 73.
They found that a high burden of damaging genetic variations in these genes is associated with male infertility.
The association is also found in females, but much weaker than in males.
The analysis shows that men with genetic variants in certain genes may be more likely to exhibit cognitive and behavioral traits that can reduce their chances of finding a partner, such as lower scores on cognitive tests or an increased risk of a mental health disorder.
The researchers found that infertility in men is associated with a greater burden of damaging genetic variations (pictured), while the association is much weaker in women.
The genetic link accounts for less than 1% of the overall likelihood of childlessness, and the study authors say other characteristics (such as sociodemographic factors and personal choice) will be more important in determining whether a particular person has children.
The researchers said that across generations and at the population level, the association between devastating mutations in genes and reduced reproductive success could explain about 20 percent of the selective pressure acting on genes.
This is consistent with the significant impact on evolution of restricted genes over time.
The authors also acknowledge that the current results are based on data from a single study, all of European ancestry, and that similar studies across populations and cultures are needed.
The study is published in the journal Nature.
Not all married women in their 30s want children, and many of them feel complete without them, the writer says.
Decided: Daisy Buchanan pictured today
The writer claims that not all married women at the age of 30 want to have children.
Daisy Buchanan, the eldest of six daughters, says she joked about having a big family as a child.
But now, at age 36, married and a homeowner, she says starting a family doesn’t seem any closer than it did more than a decade ago.
Ms Buchanan wrote in the Daily Mail that it wasn’t because they couldn’t have children or because they tried and failed.
Instead, she and her husband made the decision because neither wanted to have a child.
She wrote: “We have just realized, both independently and together, that we do not need a child to make our family feel complete.
“We don’t need a child to be happy. And frankly, we’re nervous about what kind of world we’re going to have to bring a child into.”
She added: “I believe that motherhood should be available to anyone who wants it.
“But I also think we should tell women that if they don’t want it, that’s fine too.”