I got this on "play alone", and "theatrical" while going for the achievement.
*On this playthrough, whenever I had the option with 2 heart options, I selected the left one. If there were two brain options I selected nothing or said nothing.*
Once you get to "trapped", (the room you get locked into after you enter the ship.) Select heart options with Conrad. After the conversation, walk over to Alex and Fliss and talk to them. Keep selecting the heart options and if there are two heart options, select the left one.