+To which it is replied: evolution wouldn't necessarily select for that. Survival-relevant opportunities are often rivalrous: two squirrels can't both eat the same nut, or hide in the same one-squirrel-width hole. Or as it was put in a joke popular amongst the west-valley ground squirrels (according to Harrod's post-habilitation thesis on pre-intelligence in the days of auld lang syne): I don't need to outrun the _predator_, I just need to outrun my _conspecifics_. Thus, secrecy instincts turned out to be adaptive: a squirrel keeping a valuable secret to itself and its friends would gain more inclusive fitness than a squirrel who shared its knowledge freely with anysquirrel who could listen.
+
+A few students inquire further: but that's a _contingent_ fact about the distribution of squirrel-survival-relevant opportunities in the Valley of of Plain Speech in days of auld lang syne, right? A different distribution of adaptive problems might induce a less secretive psychology?
+
+To which it is replied: yes, well, there's a reason the ascension of Earth-that-was would be sparked by the _H. sapiens_ line of hominids some millions of years later, rather than by the Plain Speech species 9792 and 9794.
+
+
+
+[TODO: novelty instincts about secrets make cross-species friends more desirable, but species differences also make them frustrating]
+
+"I wish I had a special friend. Someone who understood me. Someone to share my secrets with."
+
+And beside them, a friend or a mate would attempt to comfort them, saying, "But _I'm_ your friend. _I_ understand you. You can share your secrets with _me_."