Hi, Stephen.
Stephen Push writes:
I assume you are referring to extant species. While your evidence is suggestive, it doesn’t rule out the possibility that our ancestors encountered more dangerous species that are now extinct.
Agreed. But, I'm still skeptical that any species of spider has ever been a major selective agent on any species of mammal larger than a small rodent. The possibility is there, and I won't deny it outright, but I doubt it.
-----
Stephen Push writes:
In fact, it is possible that a genetic predisposition to learn to fear spiders and snakes started with mammalian ancestors that predated the first primates.
Well, I've argued
for the evolution of a genetic predisposition to
learn fear: I'm only arguing that a genetically-determined fear specifically of spiders is difficult to explain evolutionarily.
I would also suggest that pushing the origin further back in mammal evolution would make it less tenable from an evolutionary standpoint, because it would imply that natural selection has maintained the specific fear for a much longer period of time. Alternatively, it might imply that arachnophobia is atavistic or on its way out.
-----
Stephen Push writes:
LoBue’s paper provides the first evidence of enhanced visual detection of spiders in young children.
I haven't really researched the topic at all from a psychological or behavioral point of view, and I don't have institutional access to the journal of the spider paper, so I haven't prepared a proper rebuttal.
I would argue that this study doesn't really distinguish between learned and genetically-determined fear.
-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.