There's a lot of conflicting data on this achievement, but here is how I got it:

Play the game with the flute player, ask all the questions about him, play fair the first time, then cheat the second time. I'm pretty sure this is one of the key decisions. Play along with the game then participate in the cheating, but don't stop the game, just show that you "get it".

Don't give tickets to the beggars until they follow you as a group, then give them a stack.

Iconoclast option when dealing with the burned man, then also stop the burning. I'm pretty sure this is one of the key decisions.

Say you're not going to kill the jumper yourself, he killed himself.

Stop the fight between the enforcer and the laborer. I had a unique dialogue option from having the bravery backstory and I chose it. I'm pretty sure this is one of the key decisions.

Gave the old guy a piece of food and asked about his life, but did not pursue info about the weapons. I just walked away after a few dialogues about himself.

Take the food and eat it, pass the test to not throw up, and then say something to the crowd. I also have him a stack of cards to distribute. I'm pretty sure this is one of the important decisions too.

The achievement popped after eating the food and saying something to the crowd.

I then went back and inquired about the weapons which started the fight, after I already had the achievement.

So my theory is:
Don't get the old guy killed
Eat the food
Stop the flamethrowers
Stop the fight and say one of the relatable options, so not the philosphical one that the rabble don't understand and not the one that is just a hardass.

I eliminated a few of the guesses I read online as well. I definitely looted every single possible container, so that's not a factor. The achievement popped before I passed under the train towards the mutant area, so nothing in that area matters. And I was only Icono rank 1, so you don't need to be higher rep.