Being smart is a huge leg up in life, but it's not a golden ticket. Intelligent people, despite their natural gifts, can, and often do, end up stalled in their careers and unhappy in their personal lives just like those of us with less lofty IQs. Why? That's what a recent poster to question-and-answer site Quora wanted to know.
"What are some stupid things that smart people do?" this inquisitive person asked, spurring a fascinating collection of entrepreneurs, techies, and students to offer their best insights into the most common missteps made by smart folks. If you're the clever type, consider yourself forewarned (and therefore forearmed to fight these errors).

1. Privileging thinking over doing

"Smart people love to think. It comes naturally to them, and they're good at it," writes entrepreneur Chris Yeh in his thoughtful answer. "But thinking only takes you so far, especially when you're trying to make an impact on the world. At some point, you have to do. Research and planning are great in moderation, but can offer the dangerous illusion of progress. In the end, the only way to make a difference is to do something. Start now."

2. Ignoring design and aesthetics

If you're an expert in a subject, it can be easy to forget that nonexperts are often much less interested in the details than you are, and much more interested in the overall feel of a thing.
"When the iPod originally came out, technical people complained about its lack of features and perceived high price ('ooh, who cares about another MP3 player, I can go buy one at Best Buy for $50′ forums.macrumors.com/show...)," offers entrepreneur Lee Semel as an example. "In the meantime, it was so cool and easy to use that normal people went out in droves to buy it." 

3. Showing excessive respect to authority figures

OK, this isn't a mistake only smart people make, but if you tend to respect the well-educated and intelligent-sounding, it can be an easy trap to fall into. "Yale psychologist Stanley Milgram was right, a lot of people (including smart people) obey authority unquestionably, even if the results are detrimental," cautions founder Arsne Hodali.
"Many smart people often seem to be followers, probably because they grow up spending so much time pleasing others via academic and extracurricular achievement that they never figure out what they really like to work on or try anything unique," adds Semel.

4. Underrating effort

Grit is often more important for success than raw talent, but because they have raw talent, smart people sometimes fail to develop grit, warn several respondents. "Smart people, who've had difficult concepts come to them easy early in life, often struggle later on when tenacity and discipline become primary qualities," claims software engineer Maurice Stephens.
Smart people are "constantly praised for 'being smart' whenever they do anything well," concurs Semel. "The danger is that they become so reliant on feeling smart and having people praise them, that they avoid doing anything that they're not immediately great at." 

5. Being overconfident

Just because you're smart in one area, doesn't mean you're smart about everything, nor does it mean that you can take shortcuts. Many smart people make the mistake of thinking it does, several people pointed out.
"One study published in the Journal of Personality and Social Psychology gave logic problems to people to solve and found that smart people tended to make more mistakes than those of average intellect, because smart people were more likely to take shortcuts or make assumptions due to overconfidence," reports student Sayan Chaudhuri.
"Smart people sometimes think that just because they are expert in their field, they are automatically qualified in areas about which they know nothing," Semel claims. "For instance, doctors have a reputation as being bad investors." 

6. Always wanting to be right

Being right has its place, but so does being kind and being sane. Smart people aren't always the best at picking their battles, according to Semel, who writes: "Many smart people act as if being right trumps all else, and go around bluntly letting people know when they are wrong, as if this will somehow endear others to them. They also believe that they can change other people's minds through argument and facts, ignoring how emotional and irrational people actually are when it comes to making decisions or adopting beliefs."
"Many smart people indulge a dangerous combination of ego and logic and behave as though being right all the time is somehow endearing," agrees Chaudhuri.

7. Overvaluing education

Don't let schooling interfere with your education, Mark Twain famously advised, but according to a handful of respondents, smart people not only often make this mistake but fail to even see the distinction. Software developer and entrepreneur Tim Scott succinctly notes that smart people often "undervalue experience," while Chaudhuri says that "a high academic pedigree can make some people think that where someone got their college degree reflects how smart they are." Obviously, often it does not.
Semel puts it this way: "Smart people often use smartness as measure of the entire worth of a person. They fail to see the value in or even relate with people who are different."
Can you think of any other common mistakes to add to this list?