Othello is too stupid to be described as a tragic hero - agree or disagree and why?

I would like to add a few other ideas about Othello's intelligence.  First of all, Iago is able to dupe or manipulate many other charactes in the play:  Roderigo, Cassio, Montano, Brabantio, Emilia, and to some extent Desdemona.  So, the fact that Othello falls to his persuasion is not that surprising--he is only one of many.  Further, Iago works on Othello for an entire act and part of another (Act 3 and Act 4, scene 1).  It takes longer for Othello to fall under Iago's spell than any other character.  Look at the persuasive techniques that Iago uses with Othello in Act 3, scene 3, and compare these to the ones he uses with Roderigo in Act 1 or Cassio in Act 2.  With Roderigo, Iago only has to repeat himself:  "Put money in thy purse."  With Cassio, Iago only uses sympathy, reassurances, and deceptive advice.  With Othello, Iago must pull out all the stops:  inference, reverse psychology, imagery, deceit, ethos.   Othello has known Iago much longer than he has known Desmona.  As a general, Othello has trust in his men.  He has no reason to doubt Iago. And Iago's seeming reluctance to tell Othello his thoughts is a powerful hook that I think almost anyone would fall for.  You must remember that Othello is not privy to Iago's thoughts as we are.

Other than Othello's trust in him, Iago's most potent weapon is Othello's latent insecurity.  When Iago delicately mentions his race, Othello begins to doubt Desdemona's faithfulness. Othello compares himself to Cassio with the phrases "Haply, for I am black" and "I am declined into the vale of years and have not those soft parts of conversation that chamberers have." Othello sees himself as black, older, and crude.  When Othello views himself this way, he jumps to the conclusion that of course Desdemona loves Cassio: how could she possibly love Othello? Cassio is white, young, handsome, well-spoken, charming. Othello is black, older, and lacks courtly speech.

This type of doubt  plagues many relationships and is most probably the root of most jealousy.  It is our own insecurities that make us jealous.  It is when we compare ourselves to others and find ourselves coming up short that we begin to doubt whether or not we can be truly loved by another.  This mindset has nothing to do with intelligence; it has everything to do with our estimate of ourselves.

Othello's leap to murder his wife seems extreme to us, and probably foolish.  But Othello, a soldier, is a man of action. In his mind, Desdemona and Cassio have committed treason, a crime punishable by death.   When Othello looks within, he sees a man who is inferior to Cassio, and he is convinced that Desdemona is lost, and that she must be executed.  Even then, he feels the need to question her (although that does no good since he has already judged her) and to spy on Cassio, who he believes confesses to an affair with his wife. In a military state such as Cyprus, Othello, as the acting head, has the authority to execute these transgressors--in the name of justice.  He is wrong; he is not stupid.