One thing about Tourette Syndrome that has always intrigued me is how thinking/talking about TS or being around others with TS will cause my tics to increase. I recognized this very early on, when talking about my tics would markedly increase their frequency and intensity, or attending a TS support group would have similar affects. I've always just taken this as a constant, and have heard from others with TS that they have similar reactions.
But it didn't just end there. I discovered that, after spending significant amounts of time together, my wife and I start to "steal" each others' tics. For the most part, we have different tics, and, as is typical with TS, those tics change over time. However, sometimes when one of us takes on a new tic, it's something that the other of us has been doing for some time. We've made it a joke, usually claiming "hey, that's my tic - give it back" upon noticing the other "stealing" a tic.
In the last couple years, as we been paying particular attention to our son's tics, I've noticed a new phenomenon in myself. As my wife sees new tics developing in our son, particularly if it's one that has the potential of being a distraction in school or causing physical harm, she'll describe the new tic to me. What I've found though, is that if she also acts out the tic, I almost always start doing the tic myself. Sometimes it just one or two times, sometimes it's for much longer periods, but it seems to only be when she reenacts them and not when she just describes them verbally.
It really is strange how the mind works.