What is the word for when someone believes something is going to be a certain way so they think it is?

For example, someone's food looks good so they think it tastes amazing even though it may not?

Or someone buys something expensive so they think it works better even though it might not?

closed as off-topic by user140086, curiousdannii, jimm101, user66974, AndyT Nov 23 '16 at 9:18

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  • "Questions on choosing an ideal word or phrase must include information on how it will be used in order to be answered. For help writing a good word or phrase request, see: About single word requests" – Community, curiousdannii, jimm101, Community, AndyT
If this question can be reworded to fit the rules in the help center, please edit the question.

  • Welcome to English Language and Usage. We have a strict rule on single word request and please write an example sentence where the word or phrase would be used. You can click on the tag to read more information. english.stackexchange.com/tags/single-word-requests/info – user140086 Nov 22 '16 at 11:01
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    I think this request could potentially be rather good, but you need to say whether the word you are looking for is a noun or an adjective; if the idiom, expression, or phrase, should be derogatory or complimentary. An "optimist" (noun) is someone who sees the positive side to everything, but someone who is gullible (adj) is a person easily fooled. – Mari-Lou A Nov 22 '16 at 11:31
  • I don't understand what you're asking. If I believe something is X, I necessarily think it is X. – David Richerby Nov 22 '16 at 17:40
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    I don't see anything in Yasmin's question indicating that the person making the assumption is necessarily frequently wrong. I believe the question is more about what is the word or phrase to describe when someone makes such an assumption. Most of the answers given: in denial, gullible, delusional, naive, brainwashed, etc... strongly infer that the initial assumption was wrong. – Kevin Fegan Nov 22 '16 at 21:51
  • @KevinFegan - agreed... although the question does make clear that someone is assessing the value of something on the basis of only partial information - which increases the likelihood that their decision could be wrong. – Dan Nov 24 '16 at 10:56

I believe the accepted term is confirmation bias:

Confirmation bias, also called confirmatory bias or myside bias, is the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses, while giving disproportionately less consideration to alternative possibilities.


I think you're looking for self-fulfilling prophecy:

a prediction that directly or indirectly causes itself to become true, by the very terms of the prophecy itself, due to positive feedback between belief and behavior.

[Source: Wikipedia]

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    This is slightly different. E.g., thinking you're going to fail an exam becomes a self-fulfilling prophecy when it makes you not bother to study (since you "knew" you would fail anyway). But OP's talking about a person's perception, like if I give you a bad grade on that test because I already thought you would fail, so I graded it looking to take points off. – MissMonicaE Nov 22 '16 at 17:17
  • Another topical example of what the OP seems to be asking about would be a person not bothering to study because he "knew" he was going to pass the exam. – Scott Nov 25 '16 at 6:10

I like delusional, but it's somewhat context dependent.

[Webster's:] Delusional - A false idea; a belief in something that isn't true.


May I offer the OP the word autosuggestion which the Cambridge Dictionary defines as, "The influencing of your physical or mental state by thoughts and ideas that come from yourself rather than from other people":

"Autosuggestion is the power of mind over matter - if you convince yourself that you are cured, you will be". (Cambridge Dictionary)

  • I don’t understand how this answers the question. The question is about somebody believing something, and being unable to distinguish his belief from knowledge. Autosuggestion is about somebody believing something, and his physical or mental state changing because of his belief. This is more like the self-fulfilling prophecy, in which something actually becomes true because the person believes it. – Scott Nov 25 '16 at 6:40

If you believe something is good even though you can confirm only partially the extent to which it fulfils your expectations of 'good' - for example someone who expects visually-attractive food to taste good, or expensive items to be better than cheaper items - you may be

trusting - having belief, or an inclination to believe, in a person's honesty or sincerity (OED);

naive - artless, innocent, showing a lack of experience, judgement, or wisdom (OED);

gullible - capable of being gulled or duped; easily cheated, befooled (OED).


If the person's expectations were strongly influenced by other people (such as really working up how great something is, so much that the person believes it must be great regardless of whether or not it is), there are two other possibilities:

in denial

in a state of refusing to believe something that is true. Mary was in denial about her illness and refused treatment. Tom doesn't think he's an alcoholic because he's still in denial.

The person simply refuses to believe something isn't true, and this is usually attributed to the idea that it's a defense mechanism because accepting they were wrong is more threatening than just distorting their perception.

brainwashed (as a result of brainwashing)

any method of controlled systematic indoctrination, especially one based on repetition or confusion: brainwashing by TV commercials.

In this case the person was so strongly influenced into believing something is true that they will seemingly reject any perception, argument, or experience that indicates that things are not as they believed.


I think you're thinking of a placebo effect.

Placebo effect (Oxford)

A beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment

An example of a placebo effect is a medical patient taking a placebo - fraudulent medicine, usually just sugar-water - painkiller but still experiencing reduced pain.

  • Could you include a reference to give credence to your answer? – BladorthinTheGrey Nov 22 '16 at 16:55
  • @Aleks fwiw, ELU requires references even for things which many other SE sites would assume to be common knowledge. If you want to meet normal standards, you'll want to include a definition of 'placebo effect' with a link to the source and in this case maybe an article discussing it. I know you're limited to two external links at the moment. – Jeutnarg Nov 22 '16 at 18:34
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    Thank you, I have edited my original post to (hopefully) reflect a more suitable response. – Aleks Nov 22 '16 at 23:08
  • I don’t understand how this answers the question. The question is about somebody believing something, and being unable to distinguish his belief from knowledge. The placebo effect is about somebody believing something, and (usually) physiological processes occurring in his body because of his belief. The placebo effect is more like the self-fulfilling prophecy, in which something actually becomes true because the person believes it. – Scott Nov 25 '16 at 6:32

It's not a single word, but you might consider the phrase motivated reasoning:

The processes of motivated reasoning are a type of inferred justification strategy which is used to mitigate cognitive dissonance. When people form and cling to false beliefs despite overwhelming evidence, the phenomenon is labeled "motivated reasoning".

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