The main reasons are that the economic functions and gender ratios of the Atlantic and Islamic trades were opposites and that many of the slaves in the Islamic world were not from Africa or of African descent, which prevented the rise of racism of the kind that exists here. In the Islamic world, slaves didn't constitute a hereditary caste that was mainly composed of manual laborers. Slaves under Islam could acquire social power as slaves (e.g., Mamluks), they were much more commonly freed than slaves in the New World, and they could marry into local families. So, descendants of slaves in the Islamic world, even outside of North Africa, did not come to be regarded as a race as they still are in the Western hemisphere, especially in North America.
They basically blended into the rest of society in the Islamic world.
<http://www.transcomm.ox.ac.uk/working%20papers/segal.pdf> GLOBALISATION AND THE BLACK DIASPORA Ronald Segal WPTC-98-15 November 1998
. . . . . . . . . . . . . . . . . . . .
Historians may dispute the degree to which the Atlantic Trade was responsible for the development of Western capitalism and its industrial revolution. But there can be no doubt of the connection. Relevantly, indeed, the reason that the statistics on the Atlantic Trade are so plentiful and precise is that capitalism kept such damning good books. Much of industry developed to supply the trade goods required for the procurement of slaves in black Africa, and some of the huge profits engendered by the trade were invested in the further development of industry. Not least, there developed too, from the predominant use to which slaves were put and from the very nature of emergent industrial capitalism, a view of slaves as essentially units of labour, in a productive process which disregarded or denied their personality.
. . . . . . . . . . . . . . . . . . . .
Slavery in Islam developed differently. To be sure, a system of black slave agricultural labour, much like that which would emerge in the Americas, had early been tried, but with such dire consequences in the great so-called Zanj rebellion of the 9th century in southern Iraq as discouraged all but rare and reduced subsequent engagements of the sort. Moreover, the need for such labour, in an Islam with large peasant populations, was nowhere near as acute as in the Americas, where European conquest led, in so many of the colonies it established, to the virtual extermination of the indigenous peoples, from the new diseases it brought and the forced labour it recklessly exacted.
Slaves in Islam were directed mainly at the service sector, as concubines, housemaids, nurses, cooks, porters, guards and soldiers. There were others employed as dockers, artisans, builders; these last, sometimes used in large numbers for public works. There were factories too, mainly in textile manufacturing, reliant on slaves. But for all such activities, slavery constituted primarily a form of consumption rather than a factor of production. The most telling evidence of this is to be found in the gender ratio. Among black slaves traded in Islam over the centuries, there were roughly two females to every male; while in the Atlantic Trade, there were two males to every female.
. . . . . . . . . . . . . . . . . . . .
The freeing of individual slaves by their owners, in conformity with Koranic precepts, was far more common. As slaves, blacks were subject to no peculiar racial discrimination in law; and, once freed, they enjoyed in law equal rights as citizens. If colour prejudice did affect market prices, the treatment accorded by individual owners, and the social advancement of the freed, this was a very different matter from the institutionalized racism in the West. If religion was undeniably a major force in accounting for this, there were also other factors. The very uses to which slaves were predominantly put affected in turn the way slaves were regarded and treated. The essentially domestic function and female gender of most slaves promoted relations between owner and slave less distant and depersonalising than were those prevalent on the plantations of the Americas. And the military use to which so many male slaves were distinctively directed relied for its very purpose on the promotion of trust and loyalty. Some military slaves rose to such positions of power that their status as slaves was more symbolic than substantial. A few, indeed, rose to become rulers themselves and by definition ceased to be slaves.
Not least, there was long in Islam no such exclusive correspondence between slavery and colour as came to exist in the West. Large numbers of slaves were drawn from among Turks and Slavs; and by the time that the difficulty of acquiring so-called white slaves had led to an overwhelming reliance on black ones, attitudes to slavery and the treatment of slaves were effectively fixed. Institutionalized racism was precluded not only by the force of religion but by social pragmatism.
-- Yoshie <http://montages.blogspot.com/> <http://mrzine.org> <http://monthlyreview.org/>