What is the difference between "bias" and "opinion"? Are they synonyms? Are all opinions biased? Is there such a thing as an "unbiased opinion"?

The sentence, "Lima beans are vile" is an opinion -- but is it biased?

  • 3
    Did you look in a dictionary? What did you find? Jan 4, 2015 at 14:37
  • "Bias" (in the sense being discussed here) means "prejudice" (though the "bias" might be "positive" prejudice if it means that, say, your son-in-law gets preferential treatment in the business you operate).
    – Hot Licks
    Jan 4, 2015 at 15:40

5 Answers 5


The word bias is usually reserved for opinions that are not impartial.

Suppose someone states an opinion thus:

Cancer is a terrible disease.

If this view is based on an impartial assessment of data, it is merely an opinion, not a bias. From all reports, cancer is a terrible disease.

Now suppose someone makes a different statement:

Women make terrible programmers.

Is this opinion based on facts? (Hardly. I've worked with some terrific female programmers.) It is not impartial, but is based on some prejudice that won't hold up upon closer examination. This is still an opinion, but it is a biased opinion (bias meaning to slant) or simply a bias.


Well, to be bias is to favour something in a way that can be seen as irrational or unfair.

An opinion is a judgement one makes on a particular subject with reasoning through facts or knowledge.

I say "bias" is better used in context if you are expressing a prejudiced opinion or an unjust pretense of someone or something. Favoritism may be a synonym to "bias".

Bias and opinion are similar and difficult to differentiate. However, the tone each noun expresses is different. To be bias is for one to use their inclination to form a prejudiced opinion on something or to favour something over another irrationally. To make an opinion on something is to form a fair view on a subject without involving one's inclination and personal experiences.

Every bias is going to be formed by one's inclination.

The two nouns are not synonyms.


Bias refers to the set of assumptions and to the (limited) range of experiences that inform an opinion.


I like this question... it's deep. "Bias" is the preconceived notion, while "opinion" may (or may not be) based on previous experience. "Give me your unbiased opinion," means "tell me what you think, without factoring in any of your previous experience(s)."

Which, (to answer your question) in my opinion, is utter baloney. Technically, there cannot be an "unbiased opinion". Of course, the multi-billion dollar advertising industry would beg to differ...

  • Opinions are what YOU have. Bias and Prejudice are what OTHER PEOPLE have. that is, nobody thinks of themselves as biased or prejudiced. They all think they actually have good reasons for their opinions. Everybody is averse to being CALLED biased or prejudiced; and, typically, the more prejudiced, the more averse. Jan 5, 2015 at 7:51

Opinion is a judgment, viewpoint, or statement about matters commonly considered to be subjective, i.e. based on that which is less than absolutely certain, and is the result of emotion or interpretation of facts. (Wikipedia definition)

Bias is an inclination of temperament or outlook to present or hold a partial perspective, often accompanied by a refusal to consider the possible merits of alternative points of view.

In other words,

  • Bias is a systematic mode of thinking, based on adhering to a given viewpoint. It frequently is characterized specifically by ignoring any facts, arguments, or opinions opposite to that viewpoint.

    Please note that a biased view is NOT necessarily always opinion based - for example, I'm biased against people who advocate killing their political opposition, based on a set of facts (historical precedence, and game theoretical models that predict that I'm likely to be one of the victims of such a person). This is a bias, because even if someone points out that they are nice people, or that their goals are good, I'd still be biased against them.

    However, more usually, the viewpoint supported by a bias is more opinion based than fact based. Which may or may not make the basis of a bias true/correct, as the following example shows:

    Let's look at a bias that most people with small kids have: they would be biased against living in close proximity to a paedophile.

    That happens to be a "correct" because it's backed up by facts, given the level of recidivism.

    Interestingly enough, MOST people holding that bias merely hold it based on opinions, without actually knowing the facts that back up their opinion, even if the opinion as stated happens to be correct. In other words, they would STILL not want to live close to a paedophile even if the statistics didn't bear their concerns; which is why it's a bias and not an informed viewpoint for many people.

  • Opinion is merely something which isn't necessarily based on facts, and doesn't in and out of itself necessarily hold any specific viewpoint (or for that matter, may or may not be correct).

    However, a specific opinion can be a result of biased outlook.

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