I'm fairly transparent with my results, mainly for a few reasons:
1. I tend to do pretty well on my assessments.

2. I'm not really judged on my results by other people and most tend to respond with "Good job!" or "Oh, well better luck next time."
3. I don't let my test results define my intelligence and my attitude means that others are less likely to do it as well.
4. My friends and I are *somewhat* competitive about our results but it's positive and helps with support and motivation.
However, discussing your results is a highly personal decision. I tend to ask others "how they went" rather than "what they got". That leaves the ball in their court - they can tell me if they went well or alright or not too good and their actual result if they want to. Sometimes, people just ask because they're genuinely curious, but there are some out there that get a kick out of 'beating' other people, in a particularly negative way. It's an awkward social situation, but everyone needs to work out their own way of dealing with it.