I would contend that this behaviour only /appears/ irrational to us,
not necessarily /is/ irrational/. Like standing on one's hind legs
and squeaking when a predator is around, it has clearly negavive
individual impact, but there may be some rationale that we've either
not come to or not privy to in regards to the behaviour. This is why
I have that insistance on the rationality of things being linked to
our possession of a model for their execution.