business. When she speaks to him, she speaks with “a voice which must have stabbed him, if he was human,” though he responds “lightly” and “cruelly” to her, as if it is nothing to him to wound her.

A sincere belief that Désirée is of mixed race herself seems to be the only thing that could compel Armand to act in such a way. He doesn’t notice her, just as he would likely not notice or in any way outwardly recognize the presence of a slave, because a person with Black ancestry would be so insignificant to him. The fact that he can speak so cruelly to her and ignore her very evident distress though she is the woman whom he fell in love with like a “pistol shot” also makes it seem as though he thinks of her as less than human now. Were he aware of his own racial heritage, it seems unlikely that he would be able to treat her so terribly. Armand’s treatment of Désirée would appear to confirm his belief that she is the person of mixed race, not him.

Further, his mother’s letter, which states, in part, “I thank the good God for having so arranged our lives that our dear Armand will never know that his mother, who adores him, belongs to the race that is cursed with the brand of slavery,” adds weight to the claim that Armand did not know about his own heritage. His parents obviously kept it a secret from him, and now he seems to want to keep it a secret from everyone else, and this is why he burns the letter. If he knew about the letter before, it seems likely that he would have burned it long ago.

The last lines of the story reveal that Armand did not know of his black ancestry.

"But above all," she wrote, "night and day, I thank the good God for having so arranged our lives that our dear Armand will never know that his mother, who adores him, belongs to the race that is cursed with the brand of slavery." (Chopin)

A very prejudiced man, Armand does not know that he is the one who bears black ancestry from his own mother.  He would behave differently looking at his baby if he knew the origins of the black features were from his side of the family. 

A careful examination of the story conclusively reveals that Armand was definitely not aware of his mother's ancestry. Note the way that when Desiree becomes aware of the dark skin of her baby, she goes to her husband, horrified and shocked, asking what the meaning of this is. The answer that Armand gives her clearly displays Armand's belief in his own pure bloodline and condemns her and his child for their racial impurity:

"It means," he answered lightly, "that the child is not white; it means that you are not white."

This harsh and cruel response clearly places the blame of their child's questionable race on Desiree, as Armand does not believe that he could ever be descended from any former slaves, as, we are told, he belongs to "one of the oldest and proudest" families of Louisiana. The way in which he treats his wife and child, after having been depicted as being so in love with them, clearly displays his ignorance of his own ancestry, which of course makes the ending of this excellent story bitterly ironic, as Armand realises that he blamed the wrong person.