Logically, the absence of data is itself a type of data.
For example, I know there are black libertarians, and I even know some things about them, although I’ve never heard of any black libertarians.
But I am sure they exist, and roughly how many of them there are (very few).
How is that possible? If their number were either zero or many, I would have heard about that. Therefore, there must be a few.
On a slightly larger scale, there has never been a single confirmed paranormal event (scientifically confirmed or otherwise). Not one ever.
I remember being extremely pissed back in the 1970s that all media reports about such claims were glib content-less blather. In the 1980s, I found out about Skeptic societies which did study such claims, and basically rejected them all. Now that was an important revelation.
Could absence of evidence really be evidence of evidence? If paranormal occurrences really never happened, would the world be any different than it actually is?
The remaining possibility is that paranormal claims might themselves be paranormal. The absence of skepticism or even curiosity does seem odd. How the heck do religions thrive for centuries?
This matters because, in some important way, humans must be either much simpler than they seem, or the world is much stranger than it seems.
If so, the strangeness appears to be deliberately hidden. Elementary statistics also suggests life should be filled with many strange coincidences that seem paranormal, but really aren’t. What if there actually are not enough such coincidences?
Mind Backup would rely on measuring currently unknown similarities between diverse human minds.
The strangenesses they have in common might include blind spots, false but necessary assumptions, and deeply irrational motives.
Missing traits to look for would be restraints on curiosity, forms of denial and self-denial, and (my personal favorite) the willingness to uncritically accept what others might call injustice and evil.