Excerpt from this article:
Facebook might understand your romantic prospects better than you do.
…The company’s team of data scientists announced that statistical evidence hints at budding relationships before the relationships start.
As couples become couples, Facebook data scientist Carlos Diuk writes, the two people enter a period of courtship, during which timeline posts increase. After the couple makes it official, their posts on each others’ walls decrease—presumably because the happy two are spending more time together.