There is some grounding in the OKCupid data, but it comes from the functional meaning of the point scores: when two people mutually rate each other four or five stars, they're both notified. A score of four or five is therefore a weak way of saying "I find this person attractive enough that I'd like to meet them". (We aren't necessarily talking strictly physical attraction, though; "everyone knows" that the scores are based on photos more than profile text, but I have no idea how true this actually is.) Scores in the 0..3 range have no direct effects, but they may be anchored in some way by the fraction of people rated 4 or 5.

This is all to the best of my knowledge; I haven't been active on OKCupid for a couple of years and they might have tweaked the interface since then. On the other hand, I do remember seeing those analytics pages when I was active.