I am playing Golden Sun: Dark Dawn and noticed that sometimes I need to give an emotional response to something that was said. Do these decisions affect anything ? Or are they purely aesthetic?
I don't think the decisions really make a difference; they're just there to let you develop your character's identity a little. Pretty much the same things will happen regardless of how you respond, but it serves as a nice aesthetic touch.
If you want a reference, I quote the following from a review:
The player is allowed to "respond" at certain points with one of 4 emotional responses (positive, enthusiastic, negative, or angry). While this has little impact on the actual game, it adds a bit of the player's personality into the otherwise mysterious silent character.