A characteristic of American culture that has become almost a tradition is to respect the self-made man-the man who has risen to the top through his own efforts, usually beginning by working with his hands. While the leader in business or industry or the college professor occupies a higher social position and commands greater respect in the community than the common laborer or even the skilled factory worker, he may take pains to point out that his father started life in America as a farmer or laborer of some sort.
This attitude toward manual (体力的) labor is now still seen in many aspects of American life. One is invited to dinner at a home that is not only comfortably but even luxuriously (豪华地)furnished and in which there is every evidence of the fact that the family has been able to afford foreign travel, expensive hobbies, and college education for the children; yet the hostess probably will cook the dinner herself, will serve it herself and will wash dishes afterward, furthermore the dinner will not consist merely of something quickly and easily assembled from contents of various cans and a cake or a pie bought at the nearby bakery. On the contrary, the hostess usually takes pride in careful preparation of special dishes. A professional man may talk about washing the car, digging in his flowerbeds, painting the house. His wife may even help with these things, just as he often helps her with the dishwashing. The son who is away at college may wait on table and wash dishes for his living, or during the summer he may work with a construction gang on a highway in order to pay for his education.According to the passage, the hostess cooks dinner herself mainly because （）