Research by Jennifer Beer, a psychologist at the University of California, Davis, finds that a face-to-face guidance system inhibits impulses for actions that would upset the other person or otherwise throw the interaction off. Neurological patients with a damaged orbitofrontal cortex lose the ability to modulate the amygdala, a source of unruly impulses; like small children, they commit mortifying social gaffes like kissing a complete stranger, blithely unaware that they are doing anything untoward.

Socially artful responses emerge largely in the neural chatter between the orbitofrontal cortex and emotional centers like the amygdala that generate impulsivity. But the cortex needs social information — a change in tone of voice, say — to know how to select and channel our impulses. And in e-mail there are no channels for voice, facial expression or other cues from the person who will receive what we say.

This is the downside, and I have had my fair share of online embarrassments over the years. But there is also an upside. My own experience with this blog is that anonymous emails are also a way for people to express their own thoughts more candidly and fearlessly than they might if they had to look me in the eye. My email in-tray each day – several hundred messages from all over the world – is a cornucopia of brutal insults, bigotry, scatology – and astonishingly articulate and honest expressions of thought, experience and opinion. I’ve learned that you can only have the good if you also have the bad. And one reason why I haven’t (yet) added comments is that by reproducing almost exclusively the good on the blog, I tend to encourage more of the better kind of candor.  From descriptions of how one feels in showers to expressions of faith to memoirs and reminiscences, the candor of the internet is a gift as well as a curse. It is one of the most treasured gifts I’ve received since starting this blog seven years ago. I don’t mind being flamed, if that’s a side-effect.