FUN LINGUISTICS FACT TIME
One form of unconscious mirroring we do all the time is adapting our syntactic structures to match our interlocuter. For example, if your interlocuter says "I passed the book to Sarah", you're more likely to later use that same structure, "I X'ed the Y to Z", rather than the other possible structure, "I X'ed Z the Y". This is called syntactic priming, and for a long time it was thought to be somewhat of an automatic process. But a recent study, Weatherholtz et al., 2014, actually found that when your interlocuter is someone who you perceive to be different from you, the effect of syntactic priming is much smaller. So even the most seemingly minute aspects of mirroring are modulated by social factors!