Double standard implies having separate or different ways of dealing with people. “Double standards” is a term used to describe a set of norms or some ethical or moral code that applies more strictly to one group than the other does. People also have double standards or a so-called “split personality” when they lay down different norms for different peoples in their lives and show a sense of bias towards some people. An honest and worthy person refrains from keeping double standards and treats everyone fairly, without any sense of bias.
Double standard shows unfair treatment of people and not treating everybody on the same ground. Having double standards for people or groups is unethical and is not expected in a society, which claims to be honest to all the citizens of the society. Having a common standard for all and sundry to abide by, is what is actually called for.