阅读理解 Sex prejudices are based on and justified by the ideology that biology is destiny. According to this ideology, basic biological and psychological differences exist between the sexes. These differences require each sex to play a separate role in social life. Women are the weaker sex—both physically and emotionally. Thus, they are naturally suited much more so than men, to the performance of domestic duties. A woman''s place, under normal circumstance, is within the protective environment of the home. Nature has determined that women play care-taker roles, such as wife and mother and homemaker. On the other hand, men are best suited to go out into the competitive world of work and politics, where serious responsibilities must be taken on. Men are to be the providers; women and children are dependents. The ideology also holds that women who wish to work outside the household should naturally fill these jobs that are in line with the special capabilities of their sex. It is thus appropriate for women, not men, to be employed as nurses, social workers, elementary school teachers, household helpers, and clerks and secretaries. These positions are simply an extension of women''s domestic role. Informal distinctions between "women''s work" and "men''s work" in the labor force, according to the ideology, are simply a functional reflection of the basic differences between sexes. Finally, the ideology suggests that nature has worked her will in another significant way. For the human species to survive over time, its members must regularly reproduce. Thus, women must, whether at home or in the labor force, make the most of their physical appearance. So goes the ideology. It is, of course, not true that basic biological and psychological differences between the sexes require each to play sex-defined roles in social life. There is ample evidence that sex roles vary from society to society, and those role differences that do exist are largely learned. But to the degree people actually believe that biology is destiny and that nature intends for men and women to make different contributions to society, sex-defined roles will be seen as totally acceptable.