It's because you're looking at it from the wrong direction. The indicators are selected because people who are shy have a higher than average likelihood of liki

It's because you're looking at it from the wrong direction. The indicators are selected because people who are shy have a higher than average likelihood of liking "programmers". If you average out a bunch of likes and you know the general personality types of people who like those groups you end up with a pretty good general picture of someones personality. I really want to see this run on one of those profiles that facebook marketing clickbots use.