I've thought about how well the categories from this article map onto Hacker News. A lot of HN users could be "Socializers". "Achievers" would obviously be those trying to maximize their karma score. "Explorers" would be people reading HN to learn stuff and share knowledge. Out-and-out "Killers" are fairly rare on HN since they usually end up marked [dead] (coincidence?), but this category could also include heavy downvoters and people who sidetrack everything into arguments.

It's interesting to consider how the design of HN influences these four categories. The scoring of HN allows "Achievers" but rewards "Socializers" (since to first approximation the more you post and the better known your are the higher your karma), and heavily punish "Killers". HN discussions somewhat penalizes "Explorers" since even the most knowledgeable responses disappear into the void of old threads after a couple days. Removing visible karma scores from comments was a blow to "Achievers" but made "Socializers" happier.

Thanks to derefr for mentioning this article yesterday.