What purpose do these symbols serve? They are a good way of communicating with illiterates - party symbols are more recognizable than printed names for an illiterate voter. They also help in communicating things faster- a red traffic light instead of showing "Stop the Cars". They are also useful for communicating with children - poison signs or skeleton signs on electrical connections. They add a bit of glamour and multimedia effect to a person or idea- music accompanying WWE wrestlers, national anthems, mobile ringtones etc. Sometimes they signify authenticity - government seals in ancient days. Sometimes they serve as shorthands- currency shortforms ($). And many a times they are there because everyone else has them- National flags, National anthems, Institutional Seals etc.
But to what extent are these symbols really necessary? As you will see in the reasons listed above- many of the purposes served by symbols are rather trivial. Many of their original purposes like proving authenticity have been made redundant in modern days of electronic replication. And they are most useful only when targeted at people without the full human faculty of comprehension - illiterates and children. One may say that I have left one the supposedly most important reasons for having symbols- creating bonds. Come on, how many people feel really closely bonded when singing national anthems before the start of a movie show? Most of the corporate symbols are merely generated because some departments need to be kept employed (giving a dogs tail to straighten). Singing patriotic songs could be a mark of defiance against colonizers- but now most nations are free. Also consider the way symbols are generated- many of them are based on animals like tiger to show aggression. Come on, you want to show that association with a lesser evolved species elevates you? But the march of symbols go on- Brands have visual signatures, brand jingles; nations keep on having flags, anthems national animals, national seals. When will symbols consolidate?
For the time being, I am thinking about a music jingle for me whenever I make an entry. Ozzy Osbourne's "You're no different than me" sounds good.