You may tell yourself that you don't follow cultural rules of rank, formality, and etiquette, but that's only because what you know and do are so ingrained that it's unconscious. I don't have a smartphone, which makes a situation like this much simpler. However, I've had discussions with my kids in which they were forced to explain why they follow the steps of modern communication formalities they way they do. Only then did they understand how complicated and ridiculous those unwritten rules can be. Yeah, texting because someone may be in class makes plenty of sense, but in other situations, you can just go ahead and admit that you want to control the timing of responses for maximum effect. This is the latest comic from Zach Weinersmith at SMBC Comics.