Chasing after a Century of Punctuation

Punctuation in writing is a recent and Western invention. This study sought to determine whether using punctuation has been changing alongside changes in formal written communication in the last 11 decades. Through an analysis of 66 Introduction to Psychology textbooks published between the years 1895 and 2000, we determined that using question marks, colons, and semi-colons have increased over time, but that using exclamation points and commas have not. A post-hoc analysis of word frequencies in early and late textbook questions suggests that at least some differences may be related authors' greater effort in recent decades to engage the reader.