One of my friends includes line breaks in his iMessages, which I find strange because it takes extra effort to accomplish the same effect of sending multiple messages. But it also allows me only one chance to respond. I can&#x27;t respond to his first paragraph while he&#x27;s typing the second, because he sent them both at the same time.<p>This makes me think that the critical difference between the &quot;Chat&quot; and &quot;Full&quot; case is the number of messages, not the UI. I would expect similar results if the &quot;Full&quot; case was three separate messages as opposed to one message in multiple paragraphs. A better &quot;Control&quot; case would have been a single message in the chat UI, with line breaks (i.e. shift+enter while in FB chat), in order to eliminate text density as a variable.<p>Dividing one message into multiple creates anxiety for the reader by obscuring when the writer expects a response. Each individual message could stand on its own, but the writer does not expect a response to each. When three messages are condensed into one, the reader has an easier time inferring that the writer expects only one response to the whole message, not one to each individual paragraph.<p>This seems to relate to the feeling of sending two highly coupled messages in quick succession, only to lose service just after the first one says &quot;Delivered.&quot;