The Bible does not specifically refer to Ham being turned black as a result of Noah’s curse. Although the Bible is not definitive on this question, some Bible scholars have come to this conclusion, and I’ll address their lines of reasoning below. The relevant passage is Genesis 9:18-27 which reads as follows:
“18 The sons of Noah who came out of the ark were Shem, Ham and Japheth. (Ham was the father of Canaan.) 19 These were the three sons of Noah, and from them came the people who were scattered over the whole earth. 20 Noah, a man of the soil, proceeded to plant a vineyard. 21 When he drank some of its wine, he became drunk and lay uncovered inside his tent. 22 Ham, the father of Canaan, saw his father naked and told his two brothers outside. 23 But Shem and Japheth took a garment and laid it across their shoulders; then they walked in backward and covered their father’s naked body. Their faces were turned the other way so that they would not see their father naked. 24 When Noah awoke from his wine and found out what his youngest son had done to him, 25 he said, ‘Cursed be Canaan! The lowest of slaves will he be to his brothers.’ 26 He also said, ‘Praise be to the LORD, the God of Shem! May Canaan be the slave of Shem. 27 May God extend Japheth’s territory; may Japheth live in the tents of Shem, and may Canaan be the slave of Japheth.'”
The key phrases for this discussion are “may Canaan be the slave of Shem” (verse 26), and “may Canaan be the slave of Japheth” in verse 27.
Historians have reasoned that as the descendants of Noah’s three sons relocated and separated (verse 19), they re-populated the world as follows:
– Shem – The Middle East nations
– Ham – The continent of Africa
– Japheth – The European and other western nations
So, it seems to make sense that the descendants of Ham may have re-populated the African nations, and, of course, these nations are predominantly black.
Those who believe that Noah’s curse turned Ham’s skin black will quickly point out that Ham was Canaan’s father (verses 18 & 22), so they stretch this curse to include Ham as well as Canaan. However, Ham had other sons as well, including Cush, Egypt and Put (Genesis 10:6). Nevertheless, it does make some sense that dark-skinned people could have come from Canaan. On the other hand, it might make more sense if dark-skinned people came from the other sons: Cush (modern day Sudan and other African nations), Egypt (obviously, modern day Egypt), and Put (modern day Libya).
However, one caveat to this logic is that the land of Canaan is in the Middle East–not Africa. So, since Noah’s curse was specifically placed upon Canaan, and perhaps not on Cush, Egypt, and Put, then all of this seems somewhat reversed. In addition, there has been much scientific study as to what changes the pigmentation (color) of skin over the course of many generations. Many scientists believe that, in general, skin color is darker for those living closer to the equator, and lighter for those living farther from the equator. So, this could also explain the black skin of the African people.
There is one more thing to consider here. Noah’s curse specifically mentioned Canaan as being the slave of Shem and the slave of Japheth. Over the centuries, it does indeed appear that the descendants of Ham (again, dark-skinned people of Africa, although not necessarily of Canaan) were in many cases the slaves of the descendants of Japheth (the western nations).