[andrewstuart2]

David Rock cites a very very similar fact in "Your Brain at Work."

I only have the audiobook currently or else I'd quote directly, but the gist is that distractions from overcommunication temporarily drop IQs an average of 10 points: 5 for women, 15 for men, supposedly. The study originally revolved around email, and presumably text/sms/chat in the 13 years since the study).

Interestingly, following up on the quote he gave led me to this blog with an exchange [1] between the blog author and the original study author.

[1] http://itre.cis.upenn.edu/~myl/languagelog/archives/002493.h...