Well, this is labeled science fiction, and not just for the time travel aspect. I know quite well that some few are pretty good at ferreting out lies they're told by others, though I've never been personally very good at this, but it certainly seemed like a trait I could plausibly assign to prehistoric humans who hadn't the distractions of us modern versions to contend with. So I did. It has the added benefit of giving Hugo a head start on finding his place in the contemporary world, which for a time stymied me a bit as I wrote this novel.
On anther topic, I might point out that this was written several years ago, so a few of my comments about homosexuality have got a bit dated. A few athletes have indeed come "out of the closet," as it were, and open homosexuality is now accepted in the military. High time for both, I'd say; I never have figured out why one's sex life should be a matter of public interest, much less concern. Isn't sex supposed to be a pretty private thing, unless one is actually in the porn industry? It always astonishes me how ready-even eager-far too many people are to make themselves busy in other folks' affairs.