Tony,

Following also the theory of my friend Alasdair White I think that those persons were never there, and were only the product of mythology and false memory

Interesting to read are the theories of neuroscientist John Coates following his research into the biological response to risk-taking, especially in highstress
environments and described the results in his 2012 book "The Hour Between Dog and Wolf."
http://www.airman.af.mil/Portals/17/002%20All%20Products/001%20Book%20Reviews/Book%20Reviews/The_Hour_Between_Dog_and_Wolf.pdf?ver=2015-09-15-083111-807
John Coates was until 2016 a senior research fellow in neuroscience and finance at the University of Cambridge.
https://www.prhspeakers.com/speaker/john-coates

Marc Moerman FINS