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I often find that my understanding of the world is strongly informed by a few key concepts. For example, I've repeatedly found the concept of opportunity cost to be a useful frame. My previous post on privileging the question is in some sense about the opportunity cost of paying attention to certain kinds of questions (namely that you don't get to use that attention on other kinds of questions). Efficient charity can also be thought of in terms of the opportunity cost of donating inefficiently to charity. I've also found the concept of incentive structure very useful for thinking about the behavior of groups of people in aggregate (see perverse incentive).
I'd like people to use this thread to post examples of concepts they've found particularly useful for understanding the world. I'm personally more interested in concepts that don't come from the Sequences, but comments describing a concept from the Sequences and explaining why you've found it useful may help people new to the Sequences. ("Useful" should be interpreted broadly: a concept specific to a particular field might be useful more generally as a metaphor.)
The idea of talking about seeing status signaling everywhere is characteristically Hanson. I would not be surprised in the least if many smart politicians and socialites throughout history had also observed this but had the good sense not to talk about it in public.
Haven't pickup artists been explicitly discussing status signalling in the context of day-to-day, person-to-person interactions since the late nineties? And biologists have noted its pervasiveness all through the mid-to-late 20th centuries, at least. I'm sure cultural anthropologists too, but I'm not as familiar with that literature. Nor am I, however, with any of Hanson's posts on the subject, but a quick glance at the links on the LW wiki's page puts them all in the mid 2000s, with nothing popping out as unusual. But I also couldn't find anything of his ... (read more)