+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 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 the 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 subspecies 9792 and 9794.
+
+Another adaptive information-processing instinct in subspecies 9792 and 9794 was a taste for novelty. Not all information is equally valuable. A slight variation on a known secret was less valuable than a completely original secret the likes of which had never been hitherto suspected. Among pre-intelligent creatures generally, novelty-seeking instincts are more convergent than secrecy instincts, but with considerable variation in strength depending on the partial-derivative matrix of the landscape of adaptive problems; Dripler's Pre-Intelligent Novelty-Seeking Scale puts subspecies 9792 and 9794 in the 76th percentile on this dimension.
+
+The coincidental conjunction of a friendship-forming instinct, a novel-secret-seeking instinct, _and_ a nearby distinct subspecies with similar properties, led to some unusual behavior patterns. Given the different survival-relevant opportunities in their respective habitats, each subspecies predominantly hoarded _different_ secrets: the secret of how to jump and land on the thinner branches of the reedy pilot tree was of little relevance to the daily activity of a west-valley ground squirrel, but the secret of how to bury nuts without making it obvious that the ground had been upturned was of little import to an east-valley tree squirrel.
+
+But the squirrels' _novelty-seeking instincts_ didn't track such distinctions. Secrets from one subspecies thus functioned as a superstimulus to the other subspecies on account of being so exotic, thus making cross-subspecies friendships particularly desirable and sought-after—although not without difficulties.
+
+Particular squirrels had a subspace of their behavior that characterized them as different from other individuals of the same age and sex: _personality_ being the technical term (coined in Dunbar's volume on social systems). The friendship-forming instinct was most stimulated between squirrels with similar personalities, and the two subspecies had different personality distributions that resulted in frequent incompatibilities: for example, west-valley ground squirrels tended to have a more anxious disposition (reflecting the need to be alert to predators on open terrain), whereas east-valley tree squirrels tended to have a more rambunctious nature (as was useful for ritual leaf fights, but which tended to put west-valley ground squirrels on edge).
+
+Really, the typical west-valley ground squirrel and the typical east-valley tree squirrel wouldn't have been friends at all, if not for the tantalizing allure of exotic secrets. Thus, special cross-subspecies friendships tended to be successfully forged much less often than they were desired.
+
+And so, many, many times in the days of auld lang syne, a squirrel in a burrow or a tree would sadly settle down to rest for the night, lamenting, "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_."