Not only does Othello hold a position of significant social status and is widely respected by senior characters, but he knows his own worth. As he so eloquently says in act I scene ii, "my parts, my title and my perfect soul/ shall manifest me rightly-. .
Iago, who frequently refers to Othello in blatantly racist terms, at one point explains that "these moors are changeable in their wills- (I,iii). This insulting reference to Othello's race, while seemingly frank and shocking to the contemporary audience, would have been less so to a Jacobean audience as such talk was a result of the social attitude towards blacks and people of differing cultural backgrounds at the time. .
When Othello is "straight employed- (I,iii) to Venice, Shakespeare is using the Duke as a way of allowing Othello to be accepted into society - it stands out that such a senior member of the society represented in the play is so accepting someone who strongly contradicts the social norm. This has the affect of both conflicting with the audience's socially constructed preconceptions of how a society should behave towards black people, but also allows the audience to empathise with Othello.
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However, as the play progresses and Iago's "monstrous birth- (I,iii) begins to sprout in Othello's "garden- (I,iii), he begins to conform to the assumptions and expectations which he so strongly contradicted in the open stages of the play. Othello even says himself that "passion, having my best judgement collied/ Assays to lead the way- (II,iii). Othello gradually strays from his original composure and dignity to the point where a sudden outcry of "O, blood, blood, blood- (III,iii) is the only way he can express his extreme jealousy and rage. At the climax of his rage, Othello loses his virtue of reason and falls into a trance in Act IV, scene i. No longer is he able to speak with reverent diction, and his sentences become detached.