From aforementioned article:

"Nevertheless, ‘Human Resources’ practitioners persist in many enterprises, with their ‘personality’ screening. This is an evil practice. Many will have experienced job interviews for a technical role where one is required to engage in ‘role play’, or is asked silly questions like ‘if you were an animal, which animal would you like to be’, and so on. Any trained and qualified psychologist will tell you that the tests are bunkum, culled from Girlie magazines. Even voluntary, properly administered personality tests, validated on large populations, and given in un-stressful settings, are notoriously unreliable. When they suddenly pop up in an interview, without prior consent, and the candidate has to give the "right" answer when a potential job is at stake, they are a gross impertinence, and probably illegal."

The tragi-comic thing about them is your HR Drone will say something like "oh they're just an indicator, we don't rely on them" and then make you take them. And then base their decison on the results. Saves them having to do the thinking, I suppose...