CDL - Why Did English Colonists Consider Themselves Superior Indians and Africans?

The aritcle's main focus is to examine the language colonists used to describe the Natives, Blacks and themselves to try to determine if racism in America was rooted in the early seventeenth century Chesapeake. Primarily, the Natives were referred to by the colonists as Indians, the term originating from the days of Columbus.  The next most common term used to refer to the natives was "savages". In 1625, One English colonist described the natives as being "so bad a people, having little of humanitie but shape, ignorant of Civilitie, of Arts, of Religion;... more wild and and unmanly than that unmanned wild countrey, which they range rather than inhabit". However, some colonists did admire aspects of the natives including the way they "care[d] for family members and their simple, independent way of life in apparent harmony with nature. While the colonists found the Indian's way of living very un-English, color was never something they attributed to their savagery. In fact, the colonists considered the Indians white, never "red", and referred to their skin tone as tanned, and tawny. Neither of these terms have negative conotations, although pale skin was in fashion because tanned skin represented hard labor such as in fields.
Africans were a different story. In contrast to the Indians, the African's skin color was what struck the English colonists most rather than their un-English ways. Literally, black connoted many things negative, and was defined in the dictionary with words such as "dirty, foul, and having dark of deadly purposes". In contrast to white which represented purity, beauty and goodness which the English identified themselves as. Because the colonists identified as white, free, and English, everything the Africans were not, they viewed themselves as superior. Overall, Indians's contrasting style of living to the English and the parallels of the meaning of black and white with the skin color of the English and Africans, and along with the presence of slavery and English's ideas of social hierarchy caused the English to consider themselves superior to the Indians and Africans.

Why did the English colonists struggle so much to maintain posistive and productive relationships with the Indians?

The article states that the English colonists were struck most prominently by the skin color of the Africans, and never that they were uncivilized, or savages, as they referred to the Indians. Why do you think they were unable to distinguish between behavioral characteristics, which would determine if some one was capable of being "civilized", and physical characterisics?