The infertility epidemic"

Human fertility has fallen rapidly in most developed countries over the last few decades. The human population is still growing - but it is now widely forecast that we will read "peak human" in the next few decades.

The topic has attracted attention from various worriers, who are concerned that the fertility fall will eventuall lead to negative consequences - perhaps similar to what is seen to be happening in Japan.

The fall in fertility as countries develop is widely known as "the demographic transition". I prefer another term: "the infertility epidemic". This emphasizes the similarity with past epidemics - such as the smoking epidemic, the AIDS epidemic, the obesity epidemic and the opiod epidemic. The term "infidelity" has some defects - since it typically refers to lack of fertility if people are trying to make babies - whereas the problem here also involves people not even trying to make babies. We could perhaps call it "the childlessness epidemic" if that is seen as a big issue.

What's the cause of the infertility epidemic? This has been treated by various authors. Boyd and Richerson famously explained how cultural evolution caused the demographic transition in "Not By Genes Alone".

As with the other epidemics I mentioned, I favor the symbiote hypothesis: some small, rapidly-reproducing agent is out-evolving the human hosts. Sometimes these are helped along by humans - the smoking and opiod epidemics were spread by advertising and marketing memes from big phood and big pharma - but there were also humans involved in helping these messages on their way.

The symbiote hypothesis typically leaves open the identy of the symbionts - and there may be multiple different kinds involved. For example, the obesity epidemic was spread by memes from fast food companies - but candida albicans was also likely involved.

What symbiotes are involved in the infertility epidemic? I would draw attention to memes. Sterilizing their human hosts is a common interest of many memes - and memes reside in the brain which puts them in a good position to divert host resources from host reproduction into meme reproduction. However, I suspect viruses are also involved.

Many persistent viral infections are also in a position to divert host resources from host reproduction into virus reproduction. Some persistent viral infections are known to negatively impact fertility. HPV is a famous example of human parasite-induced sterility. It blocks the fallopian tubes of women with cancer cells - preventing future births.

While the identity of the symbiotes is of interest, it doesn't really matter for the symbiote hypothesis of infertility - any and all symbiotes will do.

References

• Cultural opportunistic infections
• Why people kiss

The problem with Robin Hanson's cultural drift

Robin Hanson has developed an interest in cultural evolution. I've previously blogged about that here. However, I am not sure about some of Robin's claims. He believes that human values are subject to what he calls "cultural drift" - and that we are making too many undirected value changes in a row and so risking going off the rails (adaptively speaking) - resulting in issues like the demographic transition - or the fertility crisis - as we perhaps ought to start calling it.

I wrote up my objections here - and reproduce them in this post:

Why do human values have this problem, while science, math, technology and language do not? That seems fairly simple: science, math, technology and language are places where the interestes of memes and genes are aligned. Whereas values are an area where they are typically different.

It is the common interest of many memes to turn humans into meme spreaders: preachers, teachers and influencers - and to make sure that no DNA-based offspring distract them from this task.

The problem is not anything to do with making too many undirected value changes in a row and then going off the rails. If that was the problem then math, science and technology would have the same issue. It's because human DNA genes now have a powerful opponent. A systematic competitor for reproductive resources.

This is why I am opposed to the "drift" story. It seems like a misdiagnosis of the problem. It makes it harder to solve our problems if we don't have an accurate picture of their causes.

My other objection is to Robin's terminology. I would prefer the term "cultural drift" to be a synonym of "memetic drift" - the cultural analog of "genetic drift". Robin uses the term differently - claiming that he is using the common meaning of the term "drift" in the dictionary. I think that Robin's somewhat irregular use of terminology likely to cause confusion.