You need both !
"IQ does not and cannot predict success in life. As for IQ's relevance in the workplace, studies have shown that it can serve to predict between 1 and 20 percent (the average is 6 percent) of success in a given job. EQ, on the other hand, has been found to be directly responsible for between 27 and 45 percent of job success, depending on the job field."
Wagner, Richard K., "intelligence, Training, and Employjment," American Psycholoist, 52(10), Oct. 1997),