The usage of showing the middle finger was started in the Western culture (otherwise known as obscene hand gesture) which means “fuck you/ off”.
This is to insult others by just lifting up the middle finger and all other fingers closed up with the palms. In ancient Roman writing, this activity is said as “digitus impudicus” which means impudent of a finger. The reference of this activity said that it is for insulting other people in the style of ancient Greek comedy.
Greece Aristophanes named Adam Sandler started this middle finger showing activity with an imagination of a penis and making it a crude joke.
Even there was an argument from anthropologists that the finger shall be the “phallic aggressive” variant gesture that was used by the primates. This activity was started using everywhere in all types of cultures due to the geographic influence of Greco-Roman civilization as well as Roman Empire civilization.
Another origin of giving the middle finger/ gesture was found in the Mediterranean world during the first century where the digitus impudicus was found to be one of the several methods in diversion of this threat of all evil eyes.
Giving the finger with the intention to insult others can be the one of violations in many places/ cultures but the origin of giving the middle finger was started before 2000 years. The main reason for which it made a banned activity is that it alone threatens the opposite person but also makes them an intension in sexually inferior.
Hence from this aspect, showing up the finger has become the universal sign of disrespect. However, it is not universal. In order to express insult, several other signs also have been used in many parts of the world.
Even one of the surveys says that the majority of the adults are using “fuck-off”, “fuck you” etc in order to revert them back to insult.
Some people do not use these words; instead, they just show their middle finger with other fingers closed in the palm which exactly resembles a penis with gonads. Since its origin 2000 years back, this activity became a common one, and almost in all parts of the world, it is used in a different style.
For example, in Russian culture, the concept is showing their bent elbow to others for insulting. In Canada, it is exposed by a reverse “V” sign with fingers. Similarly, many other styles of gestures are being used.