"As Penenberg tweeted, they measured his hormonal levels with surprising results:
'In those 10 minutes between blood batches one and two, my oxytocin levels spiked 13.2%.... Meanwhile, stress hormones cortisol and ACTH went down'"
I can see this. I would imagine that Tweeting (or Facebook) becomes a sign of acceptance. I would imagine that it is the acceptance factor that lowers stress and increases oxytocin levels. In a way, not unlike trading, or at least herding.
(here is a look at it from Mashable.com)