As an older dad, Paul Raeburn's most recent blog, "More bad news on the risks faced by the children of older fathers" caught my interest. He notes at the opening of his blog that the research he's reporting on is widely cited, "but the findings have not been put in the proper context." He ends his blog by asking if the findings offend middle-age men? I have important points to add related to both context and offense.
Paul's blog summarizes some recent research. I won't repeat it here. His blog is just a click away. I will simply quote his introductory sentence, "A study of the children of older fathers has found subtle impairments of intelligence and other mental abilities during infancy and childhood."
I appreciated that Paul put a link to the journal article in his blog. It saved me time finding the original publication. I simply had to check the facts he reported. As an older dad and a scientist, I had to read about the data and the analysis. As I suspected, there are a number of important issues to consider.
Context
Paul writes, "The story has been widely reported, but the findings have not been put in the proper context. This is only the latest in a series of problems identified in the children of older fathers, an area of study that has been widely overlooked."
I don't think this is the "proper context" for understanding this study. In fact, the last sentence in the original research article really provides the most important context for understanding these results. The author's of the study write, "While most of the neurocognitive differences were small at the individual level, these could have important implications from a public health perspective."
What's the context here? First, at the individual level, the effects were small. So small in fact, I can't believe it's worth reporting. In addition, in terms of context, these findings are not meaningful at the level of individuals (just as heritiability coefficients having nothing to say at the level of the individual).
Furthermore, the authors of the study actually write, "it is important to note that these analyses investigated neurocognitive outcomes only until age 7 years, and it is feasible that the offspring of older fathers ‘catch up' during later childhood. How the subtle neurocognitive features associated with APA translate into later educational and mental health outcomes across the lifespan remains to be determined." (Note: This is how Paul paraphrased this statement by the researchers: "The study, in the current issue of PLOS Medicine, noted that the cognitive deficits were small, and that the children of older fathers might "catch up" to their peers as they get older. But nobody knows whether these early deficits might have implications for the children's development across their lifespans, the authors said." - Quite a difference in meaning here, I think.)
In other words, the very small differences noted may not even have lasting effects. Quite frankly, in terms of development, even larger differences in functioning "come out in the wash" as kids grow up. So many other factors play a role in the development of intellectual functioning and cognitive ability that the differences noted in this study are not meaningful (statistically significant perhaps, but with a sample size of over 33 thousand, anything can be found to be statistically significant).
Perhaps a more important context for these results is just what this type of research implies. Paul concludes his post by writing, "These risks should be understood by every older father who's considering having children."
Why? Not only are the cognitive differences that were noted in this study small, the implications of Paul's statement is that perhaps knowing this would influence someone's decision about having children later in life. I would hope not.
If we're worried about risk to children from a "public health perspective" (which is the limit of the actual researchers' focus), there are more important avenues for investigation. And, if we're actually interested in maximizing the intellectual capacity of our children, there are other better predictors of a child's intelligence and mental abilities - the parents' own intelligence and mental abilities is one clear example. Could you imagine Paul's blog ending with a sentence that implied that parents should understand the potential risks of having a child with below average intelligence if they have average or below average intelligence? We give that attitude a label - eugenics.
On offense
I noted earlier that Paul ended his blog by asking these questions: "Do the findings offend middle-aged men's sense of themselves, of their vitality and power? Do they puncture the image of the father as defender of the family?"
As an older than middle-aged man, these findings do neither of these things to my sense of self or other men my age or older. What these findings do remind me of is the story of the drunk looking for his keys under the lamp post, not because he dropped his keys there, but because that's where there was some light.
Large-sample epidemiological studies produce lots of light. A better question is where should we focus the beam (and our research efforts)? In a society that's plagued with substance abuse, violence, sexual abuse, neglect, dysfunctional families, substandard educational institutions, bullying, mindless media, and countless ways for children to lose their way, are the small effects noted in research related to older mothers and fathers really a concern? This older dad thinks it's laughable.
