All human life is here: there are more than 400,000 Mass Observation papers at Sussex University and they still pour in. Now researchers are finding out why people reveal their lives in this way

A study funded by the Economic and Social Research Council of people who write for Mass Observation found that many correspondents write to help them organise their thoughts, or to become representatives of others. It found that three out of four MO writers are women, aged between 40 and 70. There are regular correspondents and the archive accepts anything that is sent. Many people write massive amounts in the form of letters to friends, companies and MPs, and several keep two diaries, one to send to the MO and one to keep.