I read the article and the study (I still have enough cognitive capabilities to do both
). My conclusions:
- The impact of a pension (and I would argue any type of regular annuity payment) impacting cognitive capability makes sense, from 2 standpoints:
1. If you do not need to work, most people focus first on leisure activities that likely do not relate to working on their cognitive capabilities. The first thought is not "great, now I have more time to read the complete works of Shakespeare, take notes, and mediate on the situations described". The first thought is "great now I can be entertained or engage in things I find fun or blow that dough!"
2. The point of "less social interaction can impact cognitive abilities" makes sense. If you are getting more than enough to live on it is easier to isolate yourself from others. During your working years opportunities for social interaction came to you, in FIRE times you more have to seek out opportunities for social interaction. One can become comfortable in isolation without making that effort, and not realize how one might be declining from a cognitive perspective.
- I would argue that perhaps there is a "shift" in cognitive abilities for many who FIRE, away from whatever profession we worked in and more towards personal financial management. I see folks actively engaged in increasing their learning of all kinds of things. Look at the threads on taking SS and Roth conversions and I Bonds and Asset Allocation and Long Term Care and savings interest rates and offers for bonuses and so on and so forth. We are still engaging, though in a different way.
- Though there may be a decline, is it permanent? For example, before I retired I knew in depth dozens of technologies, and in two weeks could build a hardware and software labs running those technologies, as well as hands-on learning materials to teach others the basics of the technologies. If you asked me today "do that again in two weeks", there is no way I could do that as I have not touched many of them for a while. However, If you said "we will give you a couple of months to get up to speed, then build such a lab", I could do it, and perhaps in a little less time given some incentive (not necessarily monetary).
- The study was based on people in rural China. My question would be, beyond their work, what opportunities did they have outside of work that would maintain or increase their cognitive capabilities? For example, was there access to education classes and learning on various topics? Sometimes the root cause might be a lack of access.
Overall, I do think it is a good caution that one should continue to engage at some level socially and mentally to keep one's mind "sharp"; but I do not think the danger is what the article and study may imply.