The offering of gifts in these situations is sometimes interpreted as a possibly improper effort to gain favorable treatment from that person. Various gestures are automatic and vary from culture to culture. While in other countries, burping may be seen as a complement to the cook. If a person's words and gestures do not seem to match, it would be wise to ask the individual. Students will, however, dress more formally for certain class presentations.
Casual dress is also appropriate for visits in people's homes, shopping or movie theatres.
You might dress more formally for a special dinner or a special event at the University. To most Americans, personal hygiene is very important. They shower and wash their hair daily, and wear freshly cleaned clothes each day. Natural body odors are considered unpleasant and offensive , so deodorants, colognes and other toiletries are used often. Busses, trains, meetings and classes generally start on time.