Abstract
It is known that writing style depends on individuals and maintains consistency in each individual. If we can prove that some changes in writing style are caused by a significant transition in writer's state of mind including mental illness, psychological change can be detected from a change of writing style. Previous studies showed that, for a specific novelist, a transition in the writer's mind leads to changes in its writing style. However, little research has been conducted on population studies, because it is difficult to sample many people who have the same type of mind transition. To solve this problem, assuming that women make internal transitions when they become mothers, we constructed a large corpus of their blog entries before and after their delivery. If we select features that depend on the contents of the text such as frequency of words, we will find the changes of writing style based on shifts of their lifestyles rather than their internal transitions. Therefore, we used characteristics that do not depend on the topics of the text such as frequency of non-content words and bigram of parts-of-speech. This study shows that their internal transitions associated with childbirth causes their writing style change.
https://ror.org/00p4k0j84 
