Racism
The main conflict centers around the issue Armand has about Desiree's supposed mixed racial background. His hatred for the black race runs so strong that without thinking too hard about the possibility that the child's somewhat darker complexion could have been because of him, he effectively abandons Desiree. The antebellum Louisiana setting shows how the racial hierarchy of the time has a psychological impact not only on the black slaves as a result of subjugation, abuse by their owners, and forced labor - completely stripping them of their humanity - but also how slavery affects the psychology of the white slave owner.
The incredible fear that Armand harbors about how Desiree is supposedly mixed leads him to think that marrying her, being with her, giving her the attention that he did, and having a child with her has completely tarnished the name of his family and his home. He refuses to believe Desiree, despite her desperate attempts that almost conclusively show that she is indeed of pure white heritage (at least insofar as her skin is even whiter than Armand's). He falls into a state of complete indifference - his hatred is so pure, so raw, and so great that nothing, until he reads his mother's letter, could convince him that he has black blood, and that he was the reason why his son has a darker skin complexion. Armand is blinded by his emotions - first of love for Desiree and then of hatred of the black race - and both emotions are so intense that it is not until the end that he realizes how wrong he is about Desiree and about his own heritage.
Kinship
What we see in this story are two extremes of kinship: Monsieur and Madame Valmondé very willingly take in Desiree as a baby who they knew nothing about. There were theories among the townspeople that she was left by a party of traveling Texans, but that did not seem to make a difference for the Valmondés. They took in Desiree as she was, and it was only when Armand took a fancy to her as a grownup that Monsieur Valmondé cautioned Armand to at least consider the background of Desiree. When Desiree realized what Armand thought about their child and about her racial background, she writes a heartfelt and urgent letter to Madame Valmondé. The Madame sends back a brief reply: "My own Desiree: Come home to Valmondé; back to your mother who loves you. Come with your child." It is more than evident that regardless of all that has happened - and from the tone of Valmondé's letter it seems that she knew something like this was going to happen - Valmondé very enthusiastically tells Desiree to come home. Moreover, she tells her to bring the baby as well.
This uncompromising and unconditional operates quite apart from the kind of kinship that Armand exhibits, which is full of haste, of rash, uninformed decision-making, and of uncontrolled (and unchecked) emotional expression. Armand forgoes and breaks off his ties with Desiree almost as quickly as he initially built them, and does so in a similarly impulsive manner. His decisions are made in the spur of the moment. It is this ill-natured temperament and mentality that creates problems for Desiree and for Armand, and eventually leads to both of their downfalls (assuming that Armand's realization of his true racial heritage is something that he is unable to accept or live with).
Denial
At first Desiree is unable to comprehend the reason why Armand has become so hostile to her. She refuses to believe that she is anything but white - nothing about her appearance suggests otherwise. In fact, Armand's darker skin might indicate that he is the one of mixed racial heritage. At the same time, what Chopin leaves the reader with is this kind of cliffhanger: how exactly does Armand process and understand that fact his mother was black? It would seem that, at least if past behavior is indicative of anything in the future, Armand would not take this information about race lightly. It is unclear what he would do: would he deny his racial identification? Would he hate himself because he is half black? There is in fact, to some degree, a difficulty in accepting the realities of race. All his life, he was the master, the dominant being. But after learning about his mother, would he deny himself what he denied others? It may be the case that if Armand truly believed in the racialized hierarchy of his day, in the inferiority of black people, and in the supremacy and superiority of white people, he (ironically) would sell himself into slavery or some kind of bondage. On the other hand, the psychological impact of this newfound information may lead him - as he is quite a religious individual - to repent and atone for his sins and to possibly go looking for Desiree and their child. However, this is completely left to the reader's imagination. What is clear is that Armand slowly comes to terms with his child's skin tone, which he sees as God's (apparent) unjust punishment. He denies that he did anything wrong at all to deserve this. At the end, he comes to realize that he was the sinner all along.
Irony
Despite Desiree being the one in the relationship to show more compassion, compromise, and commitment, she ends up (at least the reader can infer) dying after walking into the wilderness with her child. On the other hand, Armand, given his uncompromising animosity, inability to understand the feelings of others, and lack of prudent judgement, ends up with his name, his home, his property, and his slaves intact. But in one respect, he may have ended up facing the more severe punishment: his incredible racism and hatred for the black race is something he has to live with for the rest of his life (assuming he does not commit suicide, which given his hatred, he just might go ahead and do) considering the fact that he now knows that he is half black.
The Valmondés experience a fate similar to that of Desiree, especially Madame Valmondé, who was incredibly fond of Desiree, despite the fact that she was adopted. In fact, one might even argue that they face an even worse fate than Desiree because they have loved her and been incredibly supportive and good to her. Armand essentially took away the blessing they received (an adopted child in Desiree) in light of the fact that they could not have a child of their own.
Gender and Complacency
Even though she initially protests Armand's allegations about her mixed background, Desiree eventually complies and accepts Armand's position. She does not think that he will change his mind. In fact, she often looks past his devilish, satanic behavior towards her and her slaves. She looks for the good in Armand, though the same cannot be said of Armand's behavior towards her. When she asks him if she should leave, Armand tells her, "Yes, I want you to go." His tone seems dismissive, apathetic, and resolved. He is firm in his decision; he does not express shame or regret. This is in contrast to Desiree's uncertainty and unwillingness to let go. In fact, at the moment it would seem that Desiree has more of an incentive to leave Armand and to protest his behavior than vice versa. Gender roles typical of the time are embraced and in fact are internalized so greatly that both Desiree and Armand are blind to how to actually resolve the situation and see who is actually at fault.
Feminism
Though Desiree is presented as rather submissive, there are elements of feminism in the story. Specifically, it is the moments of agency that Desiree exhibits (confronting Armand instead of remaining in the dark) which showcase the slivers of hope for women that Chopin weaves into her narrative. Desiree could have allowed herself to stay quiet, but her love for and anger towards Armand convinced her to stand up for her love, her child, her marriage, and later on her racial purity.
