Surely the fig would be the *female* genitalia?

I've seen Cockneys bite their thumbs in insult - you put the thumb between the top and bottom teeth, with the fist clenched and the fingerprint bit of the thumb facing the insultee, and jerk it sharply downwards.

The clenched fist with hand on inside of other elbow is also a penile insult among Spaniards.

The English "V sign" is normally done with a sharp upwards jab.

In the 1950s there was a sign - not sure whether it was English or American - shaking the hand slowly as if to shake water off, while sneering, which meant "what a drip you are".

The fingers-and-thumb waggled like mouth gesture used to be accompanied by the words "yack, yack, yack" in the 1960s.