What this post calls "brightness," I call "ingenuity"—the process of coming up with good ideas that didn't previously exist. It's not really something society calls for very often (other than in entrepreneurial or R&D positions.) It's also the thing that "manhole cover questions" test—so if you can't imagine a company asking you that sort of question, they probably aren't that interested in you for the ingenuity you command.<p>Rather, what <i>society</i> wants is "intelligence"—the ability to iterate quickly on a problem, efficiently searching the space of solutions/ideas <i>you already have</i> to find one that is most likely to succeed. This is what is measured by IQ, and mostly comes from the ability to focus rationally on the search, instead of derailing oneself with biases or status-grabs. "Knowledge workers" are simply workers who rely on their intelligence. But look at the average knowledge worker, and you won't see much "brightness."<p>As a note to anyone who wants to be more "bright", because it <i>is</i> useful to <i>us</i> here at HN: ingenuity is formed by two skills—creativity, and critical thought. If they are developed in parallel (creativity by learning new facts to synthesize—usually by observation, but esp. from books, criticism by receiving quantitative feedback on the values of facts and beliefs—usually from conversation with peers, but esp. in school) ingenuity thrives; if one or the other races ahead, ingenuity stalls. Too much criticism, you get conformity and social anxiety; too little and you get arrogance, and an output resembling the aesthetic wasteland of 4chan's /b/. Take the middle way.