They explain it like this:
Relationships begin with a period during which couple’s court each other. On Facebook this is accompanied by an exchange of messages, visiting of profiles and comments shared on each other’s timelines.
In the hundred days before the relationship, there is a slow increase in the number of statuses shared between the couple. The moment the relationship starts, the communication between them steadily decreases. Facebook has an average of 1,67 messages a day in the twelve days before the relationship starts and it decreases to 1.53 messages 85 days into the relationship.
They draw the conclusion the couple decides to dedicate more time to each other and are physically spending more time in each other’s company.
Although interaction between the couple decreases, the content of messages is more loving and positive. The team of analysts used statistical methods to analyse the messages. In each message the number of words such as “love”, “nice”, “congratulations” and others associated with positive emotions was added up and the number of messages with words associated with negative emotions, such as “hate”, “hurt” and “bad” was deducted from that amount.
It’s clear the number of soppy messages increased dramatically after day one in a relationship.