First of all the nature of some occupations exerts vital influence on the gender preference for job holders. Being generally fitter and stronger men have evident advantages over women in physically demanding work. Although recent decades have seen the barricades lifted for females serving in the military and police force in many countries, male soldiers and policemen are still playing various dominant roles simply due to their superiority body strength, endurance and speed on average, particularly for close combats in battlefield or assault, and rescue missions carried out by special forces, By contrast, midwives, as the name suggests, are rarely male professionals not only because of the traditions but also, more importantly, pregnant women’s desire for sexual privacy.