"... (he) maybe talks like an idiot and looks like an idiot, but don't let that fool you, he really is an idiot".
Groucho refers here to the character played by Harpo. Aside from their film-relation, Groucho was always talking in the highest tones about his brother Harpo, as in his autobiography "Groucho and Me" where he compares Harpo to geniuses like Beethoven and Bach. Groucho was full of admiration for Harpo and characterized him as one of the kindest persons he ever knew. Chico on the other hand was a self-centered troublemaker for Groucho. Groucho acknowledged Chicos performance on stage and in their films but was often frustrated by Chicos selfish behavior and his lavish life-style.
Interestingly Harpo was talking in a similar way about Chico as Groucho was about him. In his autobiography "Harpo speaks" 'Harpo speaks' about Chico's great talent with numbers and musical instruments such as the piano, regreting Chico never reached his full potential due to his passion for gambling (and because he was always hanging around with the wrong kind of people).
One of Grouchos sons later said, he saw his father cry only once in his life, the day Harpo died.
