user3809: Why are there separate tournaments for men and women?
It is obvious that in physical sports men have a huge advantage, but what is the reason why in chess we differentiate by gender?

user5778: Just like in other sports women are less likely to be motivated by society to pursue greatness or a high skill level. It's the "you throw like a girl" concept. In this patriarchy women are taught that they should not be the ones performing in those tournaments. The separation between women and men in chess is just remnant of roots of the chess society, which is undoubtly patriarchaic. I don't think women will get less stares in an women-only tournament, and the setting itself won't be different too. Also if women where to be able to compete in such levels it would also give them the chance to improve by playing against those high-level players. It's just lazy to assume, those rulings are being made to protect women from this unfriendly competitive enviroment. It's also not a biological difference, that causes women to be less competetive and therefore not reach the level of top class chess players. The olympic games for example show us that women are just as competetive as men and can compete in the same enviroment as them. The seperation there is needed because women and men have a different physiology than women and can therefore show a higher physical capacity. 
english isn't my motherlanguage, so I want to apologize for some of my mistakes and bad expressions.

user315: This is probably the only frequently recurring question in chess that is ideological in nature, rather than chess-related.  By this I do not mean that it is a bad question, but only that it is a question likely to elicit bad answers, and moreover to elicit bad answers with great heat.
If you believe that men and women should not differ by sex in any significant way that is relevant to chess, then you are likely to suppose, and look for, and even imagine, bad faith as an explanation.  On the other hand, if you believe that men and women differ by sex in lots of ways, several of which are probably relevant to chess, even if we are not aware of all these ways, then there is no mystery, is there?
I have little doubt that the typical female chess master finds tends to find male-dominated tournament conditions somewhat uncomfortable.  I have little doubt that these conditions discourage some women from seriously pursuing chess.  I have much doubt however that the problem could or should be solved.  Indeed, I have much doubt that the problem is actually a problem.
One should not automatically assume that a woman is at a social disadvantage in chess, incidentally.  She may be (and so what?), but one should not automatically assume it.  Will I get hate mail if I notice the significant proportion of female chess masters who have married their top opponents?  Probably.
Typically, obviously, for whatever reason, though of course with exceptions, women are much, much less interested in chess than men are.  We don't really know whether women, as women, are inherently less capable of top-level chess than men are (women might be more capable, for all I know, though I somewhat doubt it); but, if you judge by the evidence on the face of it, well, the evidence does seem to suggest that men were on average at least a little better at chess.  (I have four sons and two daughters, and in my family the top chess talent so far is a seven-year-old daughter, who probably outplays her two elder brothers at the same age, and who has recently started giving me a lot of trouble with Alekhine's defense; but I am aware that this is not typical.  Nor would it surprise or dismay me if the daughter in question lost interest in chess as she matured.  Nor will I condone imaginary, question-begging nonsense about women being unequal at chess because fathers like me supposedly hadn't encouraged them enough.  I encourage none of my children enough to make them likely future chess masters—chess just is not that important—but if I did indeed encourage my daughter less, this would be no one's business but hers and mine.)  The inherent equality of men and women as chess players was not specifically asked, but I mention it because it is usually on the mind of people who discuss such questions.
I admit that I do not see the problem as a problem.  Since tournaments are already open to women, and since reasonable steps have already been taken to make the male-dominated atmosphere as nonthreatening as it can be under the circumstance, the circumstance is what it is.  If some women then prefer to play in strictly female tournaments, well, I have no idea (or interest) as to why they would prefer this, but it doesn't bother me.  Strictly female tournaments are fine.
Strictly male tournaments would be fine, too, in theory, I suppose, except that no one (including me) seems to be interested in organizing or participating in those.

user4543: Excellent question. There's no good reason for it. Gender differentiation probably has a negative effect on female achievement in chess. Notably Judit Polgar (until recently the highest rated woman ever to play the game) never played in female only events. 
It might have been thought that a woman could never win a Fields medal in mathematics, and this happened recently, so there's no reason to believe there wouldn't be a female world chess champion one day.

user11404: The late Doreen Kimura, a world expert on sex differences, says in her book, ‘Sex and Cognition’, that men outperform women by half a standard error in maths/problem solving.  If true and it probably is, there will be 3.6 times as many men as women in the top 2.5% of ability in that vector and six times as many men as women at or above the 0.1% level, supposing my statistics is adequate.  
Additionally men are more likely to commit absolutely, as is required at the top level.  Hence, although we may, one day, have a female world chess champ, only a few will compete at the top level.

user3270: Chess as an activity is not appealing to many women. Because there are so few women in open tournaments, it can be quite intimidating for a girl or woman to start playing the game. Imagine being one of the 1-3% of female players at a large open tournament. They receive constant attention and stares (it is much worse if they are conventionally attractive). Some women like this or are not horribly pushed away by it. Many are.
Thus, girls-only tournaments were born. In the US, there is a National Girls Championship every year near Chicago which attracts 200+ participants. This is a place for them to play without having the pressure of being basically a foreign entity at most open tournaments. I think that scholastic tournaments for girls are a very positive part of the chess world.
On the other end of the spectrum, and what I don't like, is the structure of the Women's World Championship, Women's Olympiad and various national women's championships.
My basic issue with these events is that they essentially encourage top women to get to a certain point (about 2500 Elo) and then stop improving. Take the history of Olga Girya (http://ratings.fide.com/hist.phtml?event=4195752) for example. I count 23 events that she has played since Novemeber 2012-the last time that she played in an open tournament. In many of those 23 she played not a single woman that was higher rated than herself. She has been making plenty of money, but her growth as a player has been stunted by playing in such a closed pool.
Irina Krush, in the US, recently made GM. She has been playing in US Women's Championships since she was 14 and has been one of the top two or three seeds for maybe the last 10 years. How much better would she have been if she had instead been competing against the best players in the country in the Open championship? I think it is almost unquestionable that playing against inferior opponents so often been a detriment to her improvement.

3809: <p>Why are there separate tournaments for men and women?</p>

<p>It is obvious that in physical sports men have a huge advantage, but what is the reason why in chess we differentiate by gender?</p>
 5778: <p>Just like in other sports women are less likely to be motivated by society to pursue greatness or a high skill level. It's the "you throw like a girl" concept. In this patriarchy women are taught that they should not be the ones performing in those tournaments. The separation between women and men in chess is just remnant of roots of the chess society, which is undoubtly patriarchaic. I don't think women will get less stares in an women-only tournament, and the setting itself won't be different too. Also if women where to be able to compete in such levels it would also give them the chance to improve by playing against those high-level players. It's just lazy to assume, those rulings are being made to protect women from this unfriendly competitive enviroment. It's also not a biological difference, that causes women to be less competetive and therefore not reach the level of top class chess players. The olympic games for example show us that women are just as competetive as men and can compete in the same enviroment as them. The seperation there is needed because women and men have a different physiology than women and can therefore show a higher physical capacity. </p>

<p>english isn't my motherlanguage, so I want to apologize for some of my mistakes and bad expressions.</p>
 315: <p>This is probably the only frequently recurring question in chess that is ideological in nature, rather than chess-related.  By this I do not mean that it is a bad question, but only that it is a question likely to elicit bad answers, and moreover to elicit bad answers with great heat.</p>

<p>If you believe that men and women should not differ by sex in any significant way that is relevant to chess, then you are likely to suppose, and look for, and even imagine, bad faith as an explanation.  On the other hand, if you believe that men and women differ by sex in lots of ways, several of which are probably relevant to chess, even if we are not aware of all these ways, then there is no mystery, is there?</p>

<p>I have little doubt that the typical female chess master finds tends to find male-dominated tournament conditions somewhat uncomfortable.  I have little doubt that these conditions discourage some women from seriously pursuing chess.  I have much doubt however that the problem could or should be solved.  Indeed, I have much doubt that the problem is actually a problem.</p>

<p>One should not automatically assume that a woman is at a social disadvantage in chess, incidentally.  She may be (and so what?), but one should not automatically assume it.  Will I get hate mail if I notice the significant proportion of female chess masters who have <em>married</em> their top opponents?  Probably.</p>

<p>Typically, obviously, for whatever reason, though of course with exceptions, women are much, much less interested in chess than men are.  We don't really know whether women, as women, are inherently less capable of top-level chess than men are (women might be <em>more</em> capable, for all I know, though I somewhat doubt it); but, if you judge by the evidence on the face of it, well, the evidence does seem to suggest that men were on average at least a little better at chess.  (I have four sons and two daughters, and in my family the top chess talent so far is a seven-year-old daughter, who probably outplays her two elder brothers at the same age, and <a href="https://chess.stackexchange.com/q/6257/315">who has recently started giving me a lot of trouble with Alekhine's defense</a>; but I am aware that this is not typical.  Nor would it surprise or dismay me if the daughter in question lost interest in chess as she matured.  Nor will I condone imaginary, question-begging nonsense about women being unequal at chess because fathers like me supposedly hadn't encouraged them enough.  I encourage <em>none</em> of my children enough to make them likely future chess masters&mdash;chess just is not that important&mdash;but if I did indeed encourage my daughter less, this would be no one's business but hers and mine.)  The inherent equality of men and women as chess players was not specifically asked, but I mention it because it is usually on the mind of people who discuss such questions.</p>

<p>I admit that I do not see the problem as a problem.  Since tournaments are already open to women, and since reasonable steps have already been taken to make the male-dominated atmosphere as nonthreatening as it can be under the circumstance, the circumstance is what it is.  If some women then prefer to play in strictly female tournaments, well, I have no idea (or interest) as to why they would prefer this, but it doesn't bother me.  Strictly female tournaments are fine.</p>

<p>Strictly male tournaments would be fine, too, in theory, I suppose, except that no one (including me) seems to be interested in organizing or participating in those.</p>
 4543: <p>Excellent question. There's no good reason for it. Gender differentiation probably has a negative effect on female achievement in chess. Notably Judit Polgar (until recently the highest rated woman ever to play the game) never played in female only events. </p>

<p>It might have been thought that a woman could never win a Fields medal in mathematics, and this happened recently, so there's no reason to believe there wouldn't be a female world chess champion one day.</p>
 11404: <p>The late Doreen Kimura, a world expert on sex differences, says in her book, ‘Sex and Cognition’, that men outperform women by half a standard error in maths/problem solving.  If true and it probably is, there will be 3.6 times as many men as women in the top 2.5% of ability in that vector and six times as many men as women at or above the 0.1% level, supposing my statistics is adequate.  </p>

<p>Additionally men are more likely to commit absolutely, as is required at the top level.  Hence, although we may, one day, have a female world chess champ, only a few will compete at the top level.</p>
 3270: <p>Chess as an activity is not appealing to many women. Because there are so few women in open tournaments, it can be quite intimidating for a girl or woman to start playing the game. Imagine being one of the 1-3% of female players at a large open tournament. They receive constant attention and stares (it is much worse if they are conventionally attractive). Some women like this or are not horribly pushed away by it. Many are.</p>

<p>Thus, girls-only tournaments were born. In the US, there is a National Girls Championship every year near Chicago which attracts 200+ participants. This is a place for them to play without having the pressure of being basically a foreign entity at most open tournaments. I think that scholastic tournaments for girls are a very positive part of the chess world.</p>

<p>On the other end of the spectrum, and what I don't like, is the structure of the Women's World Championship, Women's Olympiad and various national women's championships.</p>

<p>My basic issue with these events is that they essentially encourage top women to get to a certain point (about 2500 Elo) and then stop improving. Take the history of Olga Girya (<a href="http://ratings.fide.com/hist.phtml?event=4195752" rel="noreferrer">http://ratings.fide.com/hist.phtml?event=4195752</a>) for example. I count 23 events that she has played since Novemeber 2012-the last time that she played in an open tournament. In many of those 23 she played not a single woman that was higher rated than herself. She has been making plenty of money, but her growth as a player has been stunted by playing in such a closed pool.</p>

<p>Irina Krush, in the US, recently made GM. She has been playing in US Women's Championships since she was 14 and has been one of the top two or three seeds for maybe the last 10 years. How much better would she have been if she had instead been competing against the best players in the country in the Open championship? I think it is almost unquestionable that playing against inferior opponents so often been a detriment to her improvement.</p>
