I'm twitching because others are twitching (due to Tourette's)

Factual Questions
1

I know someone (whose name happens to be Josh) who has a strange habit of twitching. What happens is that suddenly, without warning, his head will turn very quickly, as if there was a fly buzzing in his ear, and he wanted to shake it away. When I asked why, he said he has Tourette’s Syndrome.

A few weeks after I met him, I noticed myself starting to twitch, though not as much or as often. I’m pretty sure Tourette’s isn’t contagious (AFAIK, it’s not caused by bacteria, viruses or anything else that can be physically transferred to someone) so I thought maybe it was just that I was cold, which made sense because it was starting to get a little colder. But then I noticed it seemed to happen even when I wasn’t cold. I asked someone about it, (just a friend, mind you, not a professional or anything) and they said I might be having a “psychosomatic reaction” to seeing Josh twitching. Is there any evidence for this type of reaction being real? How much is known about this phenomenon? Is it like when you see someone yawn, and suddenly you have to yawn?

Some other possibly relevant information: I’m 16 and Josh is about 17. Once, I noticed I was about to twitch, and forced myself not to. I usually only see Josh in the morning Monday to Friday. It seems that it doesn’t happen later in the day, or on weekends, but I haven’t been paying attention enough to confirm this. It also seems to happen a lot less now than it did when it first started.

2

Just to clear up a few things:

No. Tourettes is most definitely not contagious. It is a genetic disorder. Also, if you are 16, and you don’t have a history, I find it highly unlikely that it would suddenly manifest itself now, although I may be mistaken. (The site I linked to below says that the onset of symptoms occurs before age 18, but 16 seems pretty old to suddenly develop symptoms. See disclaimer below, however.) I know I was diagnosed when I was around 10. (I can’t recall exactly when off the top of my head.) Moreover, I believe in most cases it actually decreases in severity as you get older (it certainly has in my case).

As far as the psychosomatic reaction idea, that makes the most sense to me, but on the other hand, I am [disclamer]not a qualified medical professional.[/disclaimer] Beyond that, I don’t know what it could be.

If you want further information about Tourrettes, check out this site.