Natural selection, the grim reaper of evolution does not work by design or purpose. Chance and necessity are its driving forces and survival and fitter progeny are the foundations of individual success. Thus as Britain used its coal resources to fuel its industrialization, the air became smoggy and tree bark darker due to deposits of soot. The prevalence of darker moths increased as they could blend better with the background of darker bark and more successfully escape predation by birds. There was no premeditation, plan or foresight by nature, species or individual, just altered environment favoring a color. Similarly the evolution of wing design in butterflies to mimic a poisonous species or the appearance of leaf and stick insects to mimic leaves or sticks is an example of a blind watchmaker.
Gould has argued that a rudimentary organ may have had another evolutionary role before its complete metamorphosis and adaptation to a new organ of advantage. Dawkins in analyzing mimicry has pointed out that a slight resemblance to fool a predator in poor light could with time and evolution ratchet up to perfect mimicry by an arms race between predator and prey to struggle for miniscule advantage. The fleetness of the gazelle and cheetah stand out as a classic example of the Red Queen's words to Alice, "Here you have to run very fast just to stay in the same place to avoid falling behind".
These phenotypical traits are beneath the realm of consciousness. As animals evolved to consider the effect of their behavior on rivals or enemies, a more complex but still subconscious behavior of appearing intimidating evolved. This is what explains the cobra rearing up and fanning its ribs to form a hood to appear larger and more menacing. This explains the puffing up of frogs when threatened and the erection of hair or manes in animals when they attack or fight.
With the evolution of consciousness and the assumption of the same in other humans, we know that our appearance can influence the thinking and opinions of other humans. A form of mimicry in humans is the use of shoulder pads, padded bras, corsets and platform shoes which give a false but desirable appearance of broad shoulders, bigger breasts, thinner waists and greater height. The unique ability of ours to convey meaning and intent by speech led to the evolution of lying to deceive and hide intent. Speech becomes a tool for manipulating other humans and the natural outcome is evolution of lying to further the individual's evolutionary success by obtaining co-operation in mating and fighting. With further social evolution this malady spread to obtaining economical and political goals by duping the gullible to buy one's snake oil or getting them to vote for a candidate on the basis of false promises and platforms, concealing hidden self-serving agendas.
The ruse of promoting lies is often betrayed by the expressions on the face and the anxiety caused changes in heartbeats, sweating and altered electrical conductivity of the skin. This is why one learns to act to keep a poker face and lie detector tests are used to measure heartbeats and skin conductivity. To appear credible one is required to keep a straight face, look others in the eye and appear honest while lying.
Evolution has come up with a solution. Deep down you have to convince yourself that you are not lying and thus we indulge in self-delusion. This is what allows sundry House Speakers and members to impeach Clinton for his lies, while being total hypocrites by suppressing identical sins of their own. No individual can constantly maintain self-delusion and hypocritical behavior and thus these lying hypocrites get caught. Preliminary studies with functional MRIs of the brain provide a new tool for catching them and electrode studies of facial muscles can differentiate the false smiles of airline stewardesses from genuine ones of lovers. Sometimes even watching a person closely without any sophisticated instruments is enough to decide that they are lying.
This is why Presidents and National Security Council advisers seek refuge under executive privilege and are reluctant to testify in public. There is in contrast an eagerness to testify in private as it is not done under oath and allows one to lie like a trooper to misinform and smear with lies, the testimony of others without fear of being charged with perjury.
Interestingly, the etymological derivation of the word testify is from testes, which in American slang are better known as balls or cojones! The pretence of virtue stems from this delusion of outwardly believing one's own lies by repeating them incessantly as the subsequent tragedy of some television evangelists proves. Humane Geneva Convention for war is an example of virtuous hypocrisy as are having military chaplains or the use of god's name for money and patriotism. This pathology surprisingly is common to fanatic religious terrorists, oppressive tyrants and even elected or pseudo-elected leaders obsessed by their indecent, crooked or concealed agendas.