Spitting

Spitting is one of the ugliest pernicious habits in the world. It is very unpleasant to watch a person spitting on the earth or elsewhere. This habit is mostly spread among smokers, but some people who don't smoke also spit on the earth. Spitting has both purely physical and psychological grounds.
As for physical grounds it can be explained by excessive salivation, which in turn is caused by smoking and some medical problems. People who suffer from excessive salivation solve this problem in their own way. Some prefer to swallow their salvia; others treat it as a self-humiliation and prefer to spit the surplus of salvia on the earth. Here we come to the psychological and moral aspects of this problem.
To spit or not to spit is a moral choice. If a person is immoral he/she doesn't usually take into account what other people will think about this person. This person will spit on the ground and pay no attention to passers-by. This can tell much about this person. It means that he/she is absolutely indifferent to other people's attitude to him/her. Indifference is usually a masked aggression towards the world and society. It means that this person has psychological problems, suffers from inhibitions and hang-ups.
There is a point of view, according to which spitting under one's feet means imprecation of his/her physical body. If a person does it, he/she is likely to suffer from different diseases, injury, and accidents in future. If you spit on the earth you will catch a cold or flu by all means. Spitting can also lead to mental disorders and be harmful for creative and intellectual sphere of a person, which in turn leads to excessive aggression.
This is a terrible habit not only because it creates problems for street cleaners but because it is a manifestation of disrespect to people.
The fact is that in the process of spitting a person doesn't simply get rid of a certain quantity of saliva and lose a small amount of fluids. Thus a person loses his/her energy, and it affects negatively his/her health. So, trying to assert oneself by means of spitting, a person gets the opposite effect.
Symbolically spitting expresses not only contempt and resentment, but in some cases it can even mean curse.