In most collectivist cultures, direct confrontation of another person is considered rude and undesirable. The word is seldom used, because saying no is a confrontation; you may be right and we will think about it are examples of polite ways of turning down a request. In the same vein, the word yes should not necessarily be inferred as an approval, since it is used to maintain the line of communication: yes, I heard you is the meaning it has in Japan.
Geert Hofstede