But what does it mean?

"The East Indians would describe the Africans as impulsive hedonists..."

 Hedonists are people who live for the moment and the quote is refering to the cultural differences between the 2 groups. Since the Africans are hedonists, they would be considered low-delayers and have trouble with their desire for instant gratification in the future. It can be inferred that the East Indians are long-delayers and can resist the urge for instant gratification. The Africans do not consider their future when deciding their actions, they are always trying to live for the present and become satisfied now, rather than later.