I know that a 3rd decides the emotional quality of a chord, but what about the 5th? What does the 7th do? The 2nd, 6th, and 9th?
You can ask the Greek or look up the theories of Boethius, Glarean, Caspar Printz, Ernst Kurth etc ... The answers will be more traditional than opinion based. But did you look up wikipedia under characteristics / qualities of intervals? I did and couldn’t find much information.
The key words are psycological effects of harmonical intervals
The idea that the various musical intervals have widely disparate psychological effects has a long history in the literature of aesthetics, music theory and composition but not in experimental psychology
I used to present to my classes test sheets with a bi-polarity profile like below to get an statistical intersubjective information like they did here:
But I‘m doubting that these effects and impressions are intercultural representatives and objectives!