Is it possible that a child born to an older father will have a lower IQ than a child born to an older mother? According to an Australian study, that may just be the case.
“In general, you would predict that the offspring of older parents would do better, because the parents tend to have better socioeconomic position, stability, education, health literacy, etc.,” said Dr. John McGrath, a psychiatrist and epidemiologist at the Queensland Brain Institute in Brisbane, Australia, and one of the study’s authors.
“This is exactly what we see for the offspring of older mothers. This would probably be driven by understandable socio-cultural factors. Thus, the fact that we see the opposite pattern for fathers’ age is startling.”
In a study involving more than 33,000 children in the U.S. where intelligence scores were taken at 8 months, 4 years and 7 years of age, parentâ€™s ages were evaluated. The results indicated that children with older fathers scored slightly lower on intelligence tests than those with older mothers. This study indicates that pairing an older mother with a younger father might produce children with higher IQâ€™s.
Menâ€™s sperm degrades over time, and womenâ€™s eggs are formed early in her development. Men waiting longer to have children may not be doing justice to their children if you look at it from the IQ perspective.
What does this mean for future generations? “Over time, many societies are delaying parenthood,” he said. “Worryingly, if the adverse health and educational outcomes we see are due to new mutations in dad’s sperm cell, these will probably be transmitted to the next generation.”
Given the size of the study, the small deficits found in the children of older fathers were still significant. Perhaps the most important result from the study, noted Mark Reinecke, chair of psychology for child development at the Northwestern University School of Medicine, is that it might alleviate the fears of older women considering having children. â€œTo them,â€ he said, “the findings are reassuring. A great deal has been written about the risks of having children after 40 years of age. These findings allay these concerns, at least a bit.”
Researchers noted that while theyâ€™ve known older maternal age plays a role in birth defect risk, such as with Down Syndrome, their work shows increased paternal age also is related to risk. But exactly how the genetic mutations occur in men is unclear.
Beyond this, I would emphasize the importance of maintaining a nurturing, secure, predictable, and intellectually stimulating home environment. … That’s the key during the early years,” he said.
But the benefits that come with age do have a tradeoff, noted Dr. John Constantino, a child and adolescent psychiatrist at the Washington University School of Medicine in St. Louis. “There is a point at which maternal emotional maturity gets overshadowed by increased risk of birth defects in offspring,” he said.
McGrath cautioned that while his study’s findings need closer scrutiny, it is too soon to make any recommendations based on it.Â “I am sure your viewers and readers will want some type of guidance,” he told ABCNews.com, but it is too early to make any recommendations Research needs to be replicated and confirmed in different settings, etc. For the moment, our study suggests that paternal age, like maternal age, also should be ‘on the radar screen’ for the research community.”
“As the research evidence builds, then we can put this knowledge into the public health equation. … Our small study is one part of the jigsaw.”
ABC News – Dad’s Age May Lower Junior’s IQ by Joseph Brownstein: http://abcnews.go.com/Health/MindMoodNews/story?id=7038992&page=1