This is one of the main characteristics of the primitives, as we all know.
They can't help themselves; they were born to lie, much in the same sense everybody else was born to breathe, to eat, to get warm, to have sex, whatnot else.
Now, all people lie; I've told a few stretchers myself. It's because we're human, and fallible.
But generally decent and civilized people lie so as to avoid an uncomfortable situation, or to extricate themselves from an uncomfortable situation; we tend not to lie about perfectly harmless and innocuous things where telling the truth does us no harm.
The primitives on the other hand will lie even if telling the truth is easier and with no bad consequences.
Lying is just as much a part of them as their eyes or their fingertips; it comes with the primitive.