Back in college when I was working on a degree in Psychology I came across a book called the Luscher Color test.  It was fascinating in its premise.

The Luscher color test is described here by Wikipedia - "is a psychological  test invented by Dr. Max Luscher in Basel, Switzerland,  Max Lüscher believed that sensory perception of color is objective and universally shared by all, but that color PREFERENCES are subjective, and that this distinction allows subjective states to be objectively measured by using test colors. Lüscher believed that because the color selections are guided in an unconscious manner, they reveal the person as they really are, not as they perceive themselves or would like to be perceived."
In other words, if I had you put as few as 8 different colors in a row, based on your comparative preference for each color, I could theoretically reach some psychological conclusions about you, based on the order because of what each color represents, by itself and in combination with other colors.  It's almost like magic.
SO can the SAME thing be said about your social media usage?  Apparently it can!
As reported by United Press International , he words you post on social media can reveal more about you than you might think. Researchers have figured out a way to predict things such as mental health and diabetes status based on the language of a Facebook post.
According to UPI, the data showed, for example, that Facebook users who write posts containing the words "drink" and "bottle" were more likely to abuse alcohol, and those that posted "God" or "pray" were at 15 times higher risk of having diabetes than others who didn't use those words as much.  Why is that? How can that be.  The "drink" thing might be more obvious a connection but diabetes?  And get this - all in all, researchers looked at 21 different conditions, and found all 21 were predictable just through analyzing Facebook!
Turns out concerns about on-line privacy don't amount to much when you consider how much detailed information we give away about ourselves when we don't even know we are doing it!