Purim and Blindsight
Come to think of it, the background of Blindsight explains some facets of human psychology. For example, it explains why human beings are hardwired to hate and fear strangers. It even explains part of the anti-capitalist mentality. If somebody was unexpectedly well off in prehistoric conditions, in the Blindsight universe he/she was more likely to be a vampire.
Similar speculations might apply in the real world. There have been times in the past when more than one hominid species was around. Xenophobic instincts might date from then. If the brightest species was not the victor, hardwired envy might also date from then. (The attempted pogrom discussed in the Book of Esther was probably due to xenophobia.)