Here's a theory that just came to me a few minutes ago, but after skimming the Brain article on Wikipedia, I'm less enthusiastic about it. Just the same, here's what my original thought was:
Most Hork-Bajir have an unbifurcated brain. I say this because in the part of
Visser where Edriss 562 first enters a human host (the Iraqi), she/it/he places an emphasis on the description of how unique the human brain's division is, as if it were drastically different than a Hork-Bajir brain.
Hork-Bajir seers, on the other hand,
do have a bifurcated brain. This allows them to think more on the same level with humans and Andalites.
After skimming the
http://en.wikipedia.org/wiki/Brain Brain article on Wikipedia, I'm pretty sure that humans aren't the only (Earth) animals with bifurcated brains. Chimps and dolphins have them, too.
Question for debate: Do most Hork-Bajir lack a division in their brain like humans? And do Hork-Bajir seers have this division? (You
do remember the purpose and significance of these divisions, right? Like what each half focuses on?)