If highly advanced civilization were found to exist other than the solar system what would its effect be on humanity?

[Intoscience]

The first and foremost is to try and establish the alien's intention and agenda (assuming we are not wiped out first). If they have made the effort to visit our planet then they clearly have intent or interest.

Unless they happen to be driving past and the alien kid in the back seat says -  "look mummy that's one of those planets which I always wanted to visit" Mum reply's "I've told you before, its just one of those planets full of dumb apes wrecking the environment, nothing interesting to see there". Kid "But mummy I really wanna see". Mum "oh go on then, just this once, but be careful not to scare them, they can be very aggressive and we wouldn't want to hurt them".

Lets hope that their intent, no matter what they actually want, is not to harm us. 

[Peterkin]

The OP says, "If we were visited by a higher advanced civilization".

in which case, the aliens' attitude is the single most decisive factor.

That's quite different from the title, which says, "If highly advanced civilization were found to exist ..", which could mean that we have developed interstellar travel and go out to 'explore strange new worlds, seek out new civilizations', etc. In that case, our attitude would be more important.

What do you think it would take, in terms of social organization (rather than technology), for Earth people to mount such an expedition? Could Musk & Branson do it, or would it  require a US-Russian-Chinese collaboration?

[TheVat]

19 hours ago, zapatos said:

 😁

“…the Emperors of Blefuscu did frequently expostulate by their ambassadors, accusing us of making a Schism in Religion, by offending against a fundamental Doctrine of our great Prophet Lustrog, in the fifty-fourth Chapter of the Brundecal,  (which is their Alcoran). This, however, is thought to be a meer[sic] Strain upon the Text: For the Words are these; That all true believes shall break their Eggs at the convenient End; and which is the convenient End, seems, in my humble Opinion, to be left to every Man’s Conscience, or at least in the Power of the chief Magistrate to determine.”

-Gulliver

Thank you for a Swift and convenient End to my inquisition.