Unless the arrow of causality is the other way: those that would tend to develop memory problems do not become or remain as Taxi drivers.

Right, so we're speedrunning the studies here. Best to just stopover on TFA and see what they found.

For example, airline pilots do not have a reduced level of alzheimers deaths, and that _certainly_ is not a place where you can coast with dementia.

And taxi drivers have _increasing_ anti-Alzheimer signals - with time, the areas that are known to diminish grow _more_.