Recognition outliers reveal the boundaries where co-evolved identity perception strategies become optimal; either permitting or denying access and recognition.

Exploits of recognition are easy to find in vertebrates. The cuckoo (cucuus canorus) sneaks its eggs into the nests of other species taking advantage of egg pattern signatures Sometimes they are discovered, sometimes another species parents will unwittingly feed the young cuckoo to maturity. When patterns are exploited, systems of discovery also evolve and this is the co-evolutionary race that has become part of the human concept of identity today.  

Pattern recognition theory establishes that signatures used for identification (identity) must be repeatable, distinct and difficult to reproduce. Without the ability to recognize distinct and sufficiently complex patterns repeatably, the benefits of identity are lost. Extraordinary identity behaviors and strategies are therefore always an exception, not the rule, because they evolved to push the boundary of what is and is not good recognition.

Stoddard, M. C. et al. Pattern recognition algorithm reveals how birds evolve individual egg pattern signatures. Nat. Commun. 5:4117 doi: 10.1038/ncomms5117 (2014).

---