Back in 2008, it was reported in The Telegraph newspaper in the UK that the reason that a bird in the hand is worth two in the bush had been uncovered by scientists.
Human nature is such that supposedly individuals overvalue what he or she has and undervalue what he or she doesn’t have. A sense of entitlement actually more to do with the fear of losing a desired possession than wanting it in the first place.
The earliest English version of the proverb is from the Christian Bible translated into English by William Tyndale in 1528 and before Tyndale, by John Wycliffe in 1382.
However, the phrase reaches back to 100 A.D. when Ancient Greek author Plutarch wrote Of Garrulity, where he states:
He is a fool who lets slip a bird in the hand for a bird in the bush.
However, back in 600 BC, Greek storyteller Aesop wrote a fable entitled “The Hawk and the Nightingale.” The story went like this:
A Nightingale, perched on an oak, was spotted by a Hawk, who swooped down and snatched him.
The Nightingale begged the Hawk to let him go, insisting he wasn’t big enough to satisfy the hunger of a Hawk, who ought to pursue bigger birds.
The Hawk said, “I’d be crazy to release a bird I’ve already caught in favor of birds I don’t even yet see.”
Historically Speaking 