Tag Archives: father

Older fathers tend to raise geekier children

New research shows that older fathers tend to have more intelligent children, who are less concerned about fitting in but more focused on their own interests — traits usually bunched together as ‘geekiness’.

Darth Vader.

Luke I *hhhhhh* am your father. I’m also pretty old, that’s why you like tinkering with racing craft.
Image credits Jordi Voltordu.

Researchers from King’s College London and The Seaver Autism Center for Research and Treatment at the Icahn School of Medicine at Mount Sinai in the United States wanted to see how a father’s age influences their children’s personality. Towards this end, they looked at cognitive data from 15,000 pairs of UK twins, recorded as part of the Twins Early Development Study (TEDS). All in all, the older the father, the geekier their children tended to be, the team reports.

At the age of 12, the twins completed online tests that measured several of their cognitive traits, including some most people would bunch up as being ‘geeky’, such as non-verbal IQ, the strength of their focus on a subject of interest, and levels of social aloofness. Their parents were also asked to rate how much their child cares of the way their peers perceive them, and if they have any interests that take up a substantial chunk of their time. Using this data, the team calculated a ‘geek index’ for every child in the study.

Overall, children who scored higher on the index tended to have older fathers. This correlation held even after the team corrected for the family’s socioeconomic conditions, parent’s levels of education, and employment.

“Our study suggests that there may be some benefits associated with having an older father,” said Dr Magdalena Janecka from King’s College London and The Seaver Autism Center at Mount Sinai. “We have known for a while about the negative consequences of advanced paternal age, but now we have shown that these children may also go on to have better educational and career prospects”

Among these benefits, the team points out that the children who rated higher on the index tended to do better in school and rate higher in school exams several years after the measurements were taken, particularly for STEM (science, technology, engineering, and mathematics) subjects.

The team believes that there are several factors why older fathers may geekify their kids. For example, older fathers tend to have more well-established careers and a higher socioeconomic standing than their younger counterparts — so their children are more likely to be brought up in richer environments, have better education, and a higher exposure to STEM fields.

The findings could also help understand the links between higher paternal age, ‘geeky’ characteristics, and neurological conditions. Previous research has shown that children of older fathers are at a higher risk of some adverse outcomes, including autism and schizophrenia. Although the team couldn’t measure any effect directly, they hypothesize that some genes which encode geeky characteristics overlap with some of those who promote traits associated with autism — and older fathers are more likely to pass them along.

“When the child is born only with some of those genes, they may be more likely to succeed in school,” Dr Janecka adds. “However, with a higher ‘dose’ of these genes, and when there are other contributing risk factors, they may end up with a higher predisposition for autism.”

“This is supported by recent research showing that genes for autism are also linked with higher IQ.

The full paper “Advantageous developmental outcomes of advancing paternal age” has been published in the journal Translational Psychiatry.

older fathers

Older dads birth offspring that end up having fewer kids of their own

Evolution is not kind to older dads, a new research suggests. University of Göttingen, Germany researchers found that older fathers end up having fewer grandchildren. Apparently, mutations that appear in old age are transferred to the offspring. To improve the fitness of the gene pool, evolutionary processes limit the number of children these offspring can have of their own.

older fathers

Image: Pixabay

Previously, geneticists showed that older fathers have genetic mutations. Most of these are harmless, but some can be harmful. The first hints were reported in the 1930s by J. B. S. Haldane who noticed a peculiar inheritance pattern in families with long histories of haemophilia. He noticed that the mutation that causes the blood-clotting disorder was much likelier to be found in the X chromosomes that fathers passed to daughters. Haldane then proposed that children inherit more mutations from their fathers than from their mothers.

Much later, in 2012, researchers found the age at which a father sires children determines how many mutations those offspring inherit. By starting families in their thirties, forties and beyond, men could be increasing the chances that their children will develop autism, schizophrenia and other diseases often linked to new mutations. “

The older we are as fathers, the more likely we will pass on our mutations,” says lead author Kári Stefánsson, chief executive of deCODE Genetics in Reykjavik. “The more mutations we pass on, the more likely that one of them is going to be deleterious.”

So why dads and not mothers? Sperm is constantly renewed from dividing precursor cells, which acquire new mutations with each division. Women, on the other hand, are born with their lifelong basket of eggs.

German researchers now suggest that evolution is weeding out these mutations by inhibiting child bearing, they report in  bioRxiv.org.

They analyzed the census records from 17th and 18th century Germany, Canada and Sweden, as well as data from 20th century Sweden national population registry. About 1.3 million people were included in the analysis, in total. Researchers found that both in preindustrial and modern times children born to older fathers had fewer kids that survived past the age of 5. For every decade that a father aged from the baseline measurement, his children had between 5% (20th century Sweden) and 13% (preindustrial Germany) fewer children of their own. This effect seems to be magnified when millions of children are involved. Over many breeding cycles, potentially harmful mutations are kept at bay in the gene pool.

“We can use this understanding to predict the effect of increasingly delayed reproduction on offspring genetic load, mortality and fertility,” the researchers conclude in their paper.

The findings might concern many older fathers, but you should not worry that much. On average U.S. married men have their first child by age 25, while the average age of single men as first-time fathers is 22, according to the U.S. Department of Health and Human Services.  That’s a lot later than a hundred years ago, or only three generations. Men are also living longer, so the same mechanisms that are inhibiting child bearing might adapt. As such, the researchers emphasize that prospective fathers shouldn’t be dissuaded from having kids by the findings.

Better fathers have smaller testicles

A study has shown a trade-off between mating prowess and parenting involvement – in other words, men with smaller testicles appear to be better fathers.

father testicles

Credits: SAM EDWARDS/ALAMY

Not only are fathers with smaller testicles more involved when it comes to taking care of their offspring, but their brains are also more responsive when they see picutres of their children – which seems to indicate they care more about them.

Evolutionary biologists have long observed a trade off in primates between mating efforts to produce more offspring and the time males which spend more time taking care of their offspring. For example, male chimps, which are notoriously promiscuous have testicles twice as big as humans, they produce a lot of sperm, and they usually don’t provide parental care; they also don’t pay child support. By contrast, male gorillas have relatively small testicles, and they almost always take care of their young ones.

James Rilling, an anthropologist at Emory University in Atlanta, Georgia set out to figure out what makes a father more interested in parenting, and if there is any connection to testicle size. The researchers recruited 70 fathers of children aged between one and two years, which to me doesn’t seem like quite a relevant sample size, and scanned their brains and testes at a magnetic resonance imaging (MRI) machine. They (as well as the mothers of the children) were asked to rate “parenting involvement”. The results seem to be relevant – bar the small sample size.

“It’s a very provocative and important step,” says Sarah Hrdy, an emeritus anthropologist at the University of California, Davis. She adds that more research is needed to establish whether certain men are predisposed by biology to be more nurturing. The study’s authors say that even if men are predisposed to a certain style of parenting, nurturing dads can be made as well as born. That levels of testosterone changed as a father spent more time with his child suggest flexibility in a man’s inclination toward fatherhood.

Still, it’s not easy to draw a causality between testicle size and parenting skills. Charles Snowdon, a psychologist at the University of Wisconsin-Madison believes this study explains only a small variation in paternal care.

“There are lots of other variables that affect fatherhood,” he says, citing as examples social environment and prior experience looking after younger siblings when the men were children themselves.

Via Nature