Any way you slice it, discrimination is a bad thing. Be it age, race or gender based, discrimination causes hardship for both those that are discriminated against and those that are doing the discriminating. Discrimination in the workplace is especially dangerous, as it can lead a company to ruin both financially and legally. Refusing to hire or promote someone based upon an absolutely arbitrary quality, that has nothing to do with their basic ability to get the job done, can effectively rob the company of the opportunity to have the job done by the most capable and qualified individual.
Aside from limiting the workforce to meet a specific, pre-ordained set of characteristics, discrimination in the workplace also opens a company up to a variety of potential lawsuits, as discrimination is against the law in the United States. Failing to hire someone, based solely upon the color of their skin, their gender, their age, their religious belief or their marital status is generally prohibited, with only a few very specific exceptions. Likewise, refusing to promote an employee because they are a parent, they hold certain religious beliefs or have certain medical conditions can be cause for an employee to sue their employer.
Although we would all like to think that discrimination in the workplace is a thing of the past in this day and age, the simple truth is that many employers do still discriminate, many without even realizing that they are doing it. One of the most important ways that you can avoid even the appearance of discrimination is through very careful interviewing. Interview questions should be crafted for the sole intention of determining how well an individual will be able to perform the job at hand. Asking someone about their experience and background is relevant. Asking them whether they have children and how often those children have soccer games is not. If you chose to not hire the person with soccer games, even if it is for incompetence, the appearance that you did not select them because they have children is there.
Anyone who has ever been the victim of discrimination in the workplace knows that it is no fun. Being ostracized because of something that has absolutely nothing to do with your job and that you often have little to no control over is demeaning, belittling and generally frustrating. If you feel that you are being discriminated against. It is important to engage your human resources department so that the problem can be addressed. If you are the employer, you just need to avoid engaging in discrimination at all times.