How Darwin and Einstein replied to letters

Kurt Kleiner in New Scientist:

Both Charles Darwin and Albert Einstein relied on pen, paper, and the postal service to communicate with correspondents around the world. But researchers have now found the pattern of their replies is the same as that of computer users answering email today, with both following the same mathematical formula.

The pattern could reflect some basic biological encoding that shows up in everything from humans at work to birds foraging for food, according to Albert-László Barabási, a physicist at the University of Notre Dame in Indiana, US.

In previous work, Barabási looked at how long it took people to answer their email, and found a "bursty" pattern – most emails are answered fairly quickly, but a few sit around for a long time, and some sit around for a very long time.

To describe the pattern, Barabási created a mathematical model in which people prioritise their emails, then respond to the high priority emails quickly and the low-priority emails more slowly. When he crunched the numbers, his model fit the observed results perfectly.

More here.