To determine the relationship between letter writing and length of hospitalization, the names were secured of all patients in a mental hospital who received or sent letters during a given one-week period. There was a highly significant relationship between length of hospitalization and receiving and sending letters. The longer a patient remained in the hospital, the less likely he was to receive or send letters. Women were found to receive and send proportionately more letters than men. Patients who received letters were 10 times more likely to send letters than patients who did not receive letters.The probabilities of receiving and sending letters and receiving visitors were estimated for various durations of hospitalization. It was found that after one year in the hospital, there is a drastic reduction in sending letters, receiving letters, and receiving visitors.Abstract Teaser