In the Blood is based on Nathaniel Hawthorne's novel The Scarlet Letter and originally had a title more directly related to the novel. Parks later used the original title for another play which alludes to Hawthorne's work. In the Blood was, therefore, a title which was applied to the play after the first draft was written. This does not mean, however, that the title was a afterthought. On the contrary, In the Blood is a title which more closely follows the issue in Parks's play by abandoning the direct link with Hawthorne.
Prominent among the many meanings of "blood" are "family" and "essential nature." These are linked by the concept of genealogy. In the play, Hester has five illegitimate children, who all have different genetic heritages but the same lack of pedigree, since they are not acknowledged by their fathers. Hester's own blood, which they share, is regarded as tainted, both by society and by the children themselves.
Hester ends up shedding blood when her own son, Jabber, uses the same label—"slut"—to describe her that the rest of society uses. This society that condemns her includes the hypocritical men who have fathered her children but will not acknowledge their own blood. Violence is therefore passed down through these corrupted bloodlines, along with disgrace.