Ask Ben Franklin, Thomas Jefferson, and Napoleon--I think the answer is yes.
Can intelligent person suck at chess, forever?
Yes, I have known PhD's who were TERRIBLE at chess, even after years of trying to get them to study many games, book on strategy and tactics. Some people just don't have the aptitude to play chess, regardless of their intelligence.

Ask Ben Franklin, Thomas Jefferson, and Napoleon--I think the answer is yes.
You missed Denis Diderot.

A really unintelligent person does not have much impression about anything (whether mistaken or not),
as for subject-verb agreement should 'Is they often?' be 'Are they often?' Perhaps before becoming engrossed in a thread like this one should have a clear idea what intelligence is. I don't. The best definition I have seen so far is the 'ability to do intelligence tests', and yes, TheGrobe got the subject-verb agreement wrong too. But guys, we are not in school, only the school of Life!!

Dude, I´m not a genius, but maybe a bit above average intelligence. I´ve won a novel prize in Spain and other in Uruguay, as well as several short story prizes. Yet I suck in chess, despite I´ve been playing it since I´m 7. That doesn´t mean I can´t improve, but obviously I need to do something different to achieve that.

The main reason some intelligent people do poorly at chess and are stuck at the same rating for years is that they keep making the same mistakes over and over again.
Yes.
No
Really?! I assume that you are new to the game and are not as old as me (I`m 70). I have seen and experienced quite a few situations in my life concerning Chess. Please do not be offended by what I say as I do not want the moderators to discipline me as they have in the past for foul language and taunting people. I have worked hard to be a good person but I still have my opinions.

Intelligence and especially memory helps in playing chess, but you can be very smart and still suck at it. In addition, you will find here many dumb ppl who are very good at blitz and bullet. Usually, are the ones who brag about it, which is logical since it is the only thing they can brag about.
chess sometimes requires unintelligent and illogical moves in order to succeed, like sacrificing the queen. This is particularly true in chess tactics, where you have to consider the most crazy, retarded moves in order to solve the hard ones. The only smart thing about it is to recognize this.

Human worthy intellectual skill, like any skill, is above all highly specialized.
Stop thinking that if you got good grades in high school maths with little effort and impressed your fellow schoolmates, you're "gifted at maths". Real math starts way beyond uni level. It is like thinking you're good at chess because you beat grandma (or the guy at the pub) all the time.
Chess is only a highly specialized skill among many, you can achieve a lot in your life and never go beyond 1500.
This Patzer is highly encouraged by this, lol.

I think that especially at the lower levels chess is all about practice. And I mean real practice, where you actually stop yourself to think and ask questions. Once you get the basic questions down, it gets much easier to make progress. Problem with chess is that - unlike many other games - it's a game where simply playing a lot doesn't mean that you necessarily improve much. You can keep making same mistakes over and over again, if you never take the time to ask yourself where did you go wrong.
I'm a beginner myself, and have so far played chess for about 6 months. I haven't played all that many games compared to a lot of people, but I try to go through my games as often as possible. Trying to see where I went wrong and what was my reasoning behind it. If you never get to the root of the problem, just playing more and more games might not make you any less likely to avoid those mistakes,
For those curious, I made an excel spreadsheet about my progress in these 6 months. It's a start but should prove anyone that getting better at chess is all about serious, sometimes even a bit tedious, practice. That and a lot of tactics training. I bet that all these things related to "natural talent" like good memory, pattern recognition, creativity and good ability to calculate variations make a bigger difference at higher levels. At lower level you can improve a lot by simply practicing, and I bet you that anyone can stop "sucking" in chess if they just take their practice seriously and are really willing to put the time required to improve.
As you can see, I was a sub 900 rated player at the start of the year (played my first online games in December), and every rating ever since is my rating on the first day of each month. At the time of writing this I average +1300 on the four game modes I play.

chess sometimes requires unintelligent and illogical moves in order to succeed, like sacrificing the queen. This is particularly true in chess tactics, where you have to consider the most crazy, retarded moves in order to solve the hard ones. The only smart thing about it is to recognize this.
This is entirely incorrect. Chess is entirely logical. Not understanding a move does not making it illogical. For example, sacrificing the queen for mate is completely logical. Sacrificing the queen for a rook and 2 pieces is also logical (provided it doesn't leave you open to checkmate yourself). Tactics are all about finding the logical moves that are most forcing.
The reason intelligent people stagnate with their chess improvement is that they do not focus on improving where they are weakest. Most people, even highly intelligent ones, are not very good at self-assessment. They will think they are terrible at something and good at another, when neither may be accurate. For example, you might think you are good at tactics and horrible at positional concepts and decide you need to study Silman or Aagard (or similar). If your rating is below ~1800, I can guarantee your assessment of yourself is wrong. Another example would be when someone is told to practice tactics and endgames and they respond with the fallacious argument "but, if I'm already losing out of the opening, shouldn't I study the opening instead!?"
The key to improvement in chess (as with anything in life) is to improve your weakest parts to make them strengths, rinse and repeat. I know highly intelligent people (doctors, lawyers, PhDs) who have been stuck below 1000 for years because they fail to practice tactics and then lose games due to them (usually to kids who do nothing but study tactics!).
I don’t think it is entirely false, like you claim.
Just trying to shed some light to something that some ppl, including me, might never thought (I didn’t initially). What are tactics? Tactics are just small chess problems, usually taken from real games. I love solving problems. I am excited every time a friend has learned about a new one. I am also really good at solving them (have scored something like 1 in 5K in few such tests). That is why I also like tactics, because they are essentially small problems and in unlimited amount (unlike good problems, which are very limited). I am not good at solving tactics though (about 1800 in chess tempo) and was wondering why? How can I be highly logical (love Mathematics and coding) and also be good at solving problems and fail at solving tactics (with some having a very limited number of options to start with to add to the insult)? The answer I came up and shared above is because to solve them you have to think illogical, or to not think at all and just try in brute force all checks, captures and threats.
If you learned chess as a kid, what I say might not be true, since your brain might have learned to work as required and not easily dismiss illogical on the surface moves and always look deeper. If you learned it as an adult though, I think it might explain some difficulties. Just some thoughts!

@Taskinen, #564: I really like your attitude and approach to the game of chess!! It's excellent. And applicable to so many other different areas of life.

I think anything is possible. It's probably possible that an intelligent person can always be bad at chess. But it seems like there aren't very many good chess players who are dumb. I think an intelligent person has a much greater chance of being good at chess than an average person would.
Being average in intelligence I will probably always be average in chess ability. Forever. But since it's just a game and I only play for fun it doesnt really matter if I'm average forever.
Intelligent: (adjective)
Someone having capabilities higher than @yoshimushroom.
Just joking but no need to ask such stupid problems:
adjective