What is the name of the tendency to portray oneself in the positive light?

Question

I know it exists and it has a name...

But my google-fu skills are lacking, due to a pretty niche concept that uses a lot of generic keywords.

There is a fallacy / mental model / a tendency for people to portray themselves in a positive light.

I know about "80% of drivers thinking they are better than average" https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect and https://en.wikipedia.org/wiki/Illusory_superiority but it is not exactly what I'm looking for.

CONCRETE EXAMPLE

Have you ever taken / ingested / consumed cannabis?

Answer "YES" to this question would admit doing something illegal, with potentially negative consquences, including the fact that the researcher might be an undercover cop. Therefore, even if the genuine answer is "YES", there is a non-zero probability that the recorded answer is "NO"

To account for this tendency INSERT NAME HERE _____________ I would like to suggest an alternative design of the same question that involves a 2nd researcher

"We are aware of the tendency INSERT NAME HERE _____________

"We are working towards legalization efforts..."

"This will be treated in the strictest confidence..."

"We know that asking "YES / NO" questions about drug use can make people..."

"Our goal is to obtain more accurate estimate..."

More google-fu

"anonymity bias" - loads of interesting research papers, including one specifically about cannabis (link):

Of course the sample size is small but the discrepancy is clearly visible (other research papers confirm it too).

I am aware that anonymity might not be enough to obtain accurate results, that's why the design of the study with the 2nd researcher but I just want to sound a little bit smarter and read more about INSERT NAME HERE _____________ - surely it has a name?

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EDIT: if it does not have a name, I'll take the "Robertson Syndrome"

Answer 1

One particularly fitting term is impression management. From Wikipedia:

Impression management is a conscious or subconscious process in which people attempt to influence the perceptions of other people about a person, object or event by regulating and controlling information in social interaction. [...] Individuals construct an image of themselves to claim personal identity, and present themselves in a manner that is consistent with that image. [...] Impression management can distort the results of empirical research that relies on interviews and surveys, a phenomenon commonly referred to as "social desirability bias".

As an effect, we have social desirability bias. From Wikipedia:

In social science research, social-desirability bias is a type of response bias that is the tendency of survey respondents to answer questions in a manner that will be viewed favorably by others. It can take the form of over-reporting "good behavior" or under-reporting "bad", or undesirable behavior. The tendency poses a serious problem with conducting research with self-reports. This bias interferes with the interpretation of average tendencies as well as individual differences.

A related term is self-monitoring. From Wikipedia:

Self-monitoring [...] describes the extent to which people monitor their self-presentations, expressive behavior, and nonverbal affective displays. [...] Self-monitoring is defined as a personality trait that refers to an ability to regulate behavior to accommodate social situations. [...] Some personality types commonly act spontaneously (low self-monitors) and others are more apt to purposely control and consciously adjust their behavior (high self-monitors).