From what is this based on? It is not congruent with literature I have read on the matter. For one, gametes from the aged father are vastly more likely to incorporate denovo (typically deleterious) mutations.
PLoS Medicine: Contrasting Effects of Maternal and Paternal Age on Offspring Intelligence
Evidence is accumulating that advanced paternal age may exhibit a wider range of effects on the health and development of the offspring than increased maternal age (which is largely confined to risk for Down syndrome). Advanced paternal age is a risk factor for childhood conditions such as cleft lip and palate; childhood cancers and congenital heart defects [1]; and neuropsychiatric conditions such as autism [4], schizophrenia [5,6], epilepsy [7], and bipolar disorder [8]. Advanced paternal age also appears to affect mortality, and an intriguing analysis of family history data from European nobility found that older age of fatherhood (greater than 45 years) is associated with a reduction of about two years in the life span of daughters [9].
This is based primarily on the fact that the risk of Down's Syndrome and pregnancy complications is easily observable, whereas the risk of various other things associated to paternal age are harder to see.
For the most part, the bigger the risk, the easier it is to observe.
However, if you have hard numbers (rather than a piece that is mainly speculative), I'd love to see them.
Understand that I did not post that question for reasons of vanity. I really wanted to know what led you to that belief (I have not found much evidence supporting it) and am still interested in knowing, in order that I might update my beliefs if necessary.
I at least cited something. I picked up the article I had read most recently. Speculative or not, it was published in a peer reviewed journal by those active in the area. I urge you to do your own research and come to your own conclusion. As these things are not known one can only give hypotheses on their causes. Statistics which are often not done well in the medical field are not necessarily stronger than reasoning from first principles.
If you have access to any geneticist, autism researchers or biologist do ask them. And consider. De novo mutations are culprit for many rare diseases including those like autism (each particular case often to rare causes) with non-specific causes. In terms of the gametes which both parents provide, sperm cells unlike ova, have a vastly larger number of these errors with probability increasing with time. This is a stronger argument than something is hard to observe and does not assume that the researchers did not think of something fairly quite obvious. The reason for Down Syndrome and maternal age also has a solid biological hypothesis that is almost inverse (not new mutations but chromosomal damage, usually catastrophic -> miscarrying).
I was actually interested in what made you come to hold this belief because it is not in line with much of what I have picked up in the literature. If you can give a solid counter reference, speculative or not I would be interested. A cursory search on my part did not find anything supporting your claim.
First of all, I think my glib one-line response carried a lot more certainty than I should have expressed. My bad.
The main reason I believe maternal age is a bigger issue is because of the absence of evidence about paternal age. It's pretty well established epidemiologically that maternal age is a problem, but there is far less evidence about paternal age. That suggests that whatever problems paternal age causes, they are harder to observe. The most common reason an effect is hard to observe is because it is small.
That's the extent of it. It's more or less the same reason I take the media's latest "new study suggests XXX might cause cancer" stories with a grain of salt.
I haven't looked into this deeply at all. If you have lots of info on it, you should probably not update your beliefs.
