Hume

Page 57 Hume states "Are the manners of men different in different ages and countries? We learn thence the great force of custom and education, which mould the Haman mind from infancy, and conduct of the one sex very unlike that of the other?" And he also said "Are actions some person much diversified in the different periods of his life, from infancy to old age?"

I think that human manners are different in different man and different countries. I think that depends on the family you were raised in the education that you had that gives you the manners that you have. Manners are a learned behavior.Other countries have different manners because they have different culture.
For example in some cultures it is not uncommon to when talking to some one to stand very close and to touch the person's arm when taking to them. In our culture if some one did this that we did not know we must likely would not like it. we would back away because in our culture we are taught to keep our personial space.