Probably via @Sigrun_, a source of many interesting links.
I am posting this as a page now, because it illustrates what to me is one of the valuable aspects of blogging and Twitter: interactions with people who think differently, see things from a different angle.
Your Casual Acquaintances on Twitter Are Better
Than Your Close Friends on Facebook:
“Excerpt adapted from Smarter Than You Think: How Technology is Changing Our Minds for the Better, copyright (c) Clive Thompson, 2013.”