Belkys

It actually depends on where the person is located and around whom he or she may be.

If someone decides to talk in public is because this person feels comfortable with the language that is being used. 
If the person does not speak in public does not necessarily mean that he or she is shy but rather how secure this person is about the subject. If I do not know what the subject is about, I better stay quite. Besides, the way I am going to talk to you will be differ from the way I talk to some of my friends I am not going to talk to you in Spanish, probablemente no entenderia lo que estoy diciendo.