Tit for Tat

Ti t f o r t a t
Meaning
A blow or some other retaliation in return for an injury from another.
Origin
It's tempting to assume that this little phrase is another way of saying 'this for that' and, in a way, it is. 'Tit' and
'tat' are both the names of small blows which originated as 'tip' and 'tap'. These are recorded by Charles, Duke
of Orleans in a book of poems that he wrote while captive in England after the battle of Agincourt and first
published circa 1466:
"Strokis grete, not tippe nor tapp."
The widespread unconcern about spelling and pronunciation in the Middle Ages led to 'tip', 'tap', 'tit' and 'tat' all
to be variant spellings. John Heywood appears to be the first to have used 'tit for tat', in the parable The Spider
and the Flie, 1556:
"That is tit for tat in this altricacion [altercation]."
In the 20th century, 'tit for tat' was the source of the Cockney rhyming slang 'titfer', meaning hat. The renowned
lexicographer of slang Eric Partridge listed that in 1930, in Songs & Slangof the British Soldier:
Tit-for, tit-for-tat, i.e. hat.
This usage was popularised by the British comedian Tommy Trinder who, although he
was born several miles from the sound of Bow Bells, in Streatham, London, and
hence not strictly a cockney, exemplified cockney style to most people. He was rarely
seen in public without his titfer tat.
Most recently still, 'tit for tat' has been used as the name of the strategy in the classic
logic problem of game theory, the Prisoner's Dilemma. This strategy, which has since
been applied successfully in many real life situations, recommends a like for like
retaliation as the most rewarding response to duplicity by one's opponent.