Sorry, but how do you know this isn't some kind of placebo, exactly? This reads like pseudoscience.
I do believe some people are certainly better at determining honesty and character than others. But without any sort of blind testing, or even some kind of empirical foundation or proposed specific techniques, it's very difficult to know for sure if a particular person really is better than average or not.
I never equated the words "social radar" with "lie detector". So perhaps I confused a thing or two here. It happens.
The short version of what I claimed is if you have good empathic skills (e.g. being better able to feel the facial expression other people are making at that moment), then you'll have part of the answer of how to detect genuine people (and I believe being not genuine and lying are two completely different things).
About meditation itself and its relationship on social intelligence, there's not much written about it, since I made the term "social intelligence" up. I'd recommend reading about meditation and emotional intelligence on Science Daily. Then practice it for 5 days in a retreat and then see for yourself how it could improve your 'social radar'. I know it's a lot of effort, but in my opinion that's the minimal amount of investigation that you'd need in order to see if it holds value. The 5 day retreat is needed to gain the tacit knowledge that cannot be explained through language (just like the feeling of playing an instrument very quickly can only be practiced).
I've read articles claiming both that there exist a small percentage of people who are amazing at detecting honesty in others and different articles claiming that no such people exist, so I don't really know what the latest accepted view is.
I do believe some people are certainly better at determining honesty and character than others. But without any sort of blind testing, or even some kind of empirical foundation or proposed specific techniques, it's very difficult to know for sure if a particular person really is better than average or not.