Why did Eggers include information about abdulrahman's brothers?

Both Ahmad Zeitoun and Mohammed Zeitoun were upstanding people. Ahmed was a strong role model for Abdulrahma, teaching him how to do fish and eventually inspiring him to become follow in their father's footsteps and become a sailor. Mohammed was a champion ocean swimmer whose prowess made him a legend in Syria and the world in the 1960s. All three brothers defied the tired old stereotypes of men from the Middle East that some Americans seemed content to label them with.