Human Differences
Typically, between 1000 and 2000 melanocytes per square millimeter of skin are found. Melanocytes comprise from 5% to 10% of the cells in the basal layer of epidermis. Although their size can vary, melanocytes are typically 7 μm in length.
The difference in skin color between lightly and darkly pigmented individuals is due not to the number (quantity) of melanocytes in their skin, but to the melanocytes' level of activity (quantity and relative amounts of eumelanin and pheomelanin). This process is under hormonal control, including the MSH and ACTH peptides that are produced from the precursor proopiomelanocortin.
Albinos lack an enzyme called tyrosinase. Tyrosinase is required for melanocytes to produce melanin from the amino acid tyrosine.
Read more about this topic: Melanocyte
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“There are few things more dreadful than dealing with a man who knows he is going under, in his own eyes, and in the eyes of others. Nothing can help that man. What is left of that man flees from what is left of human attention.”
—James Baldwin (1924–1887)
“Quintilian [educational writer in Rome about A.D. 100] hoped that teachers would be sensitive to individual differences of temperament and ability. . . . Beating, he thought, was usually unnecessary. A teacher who had made the effort to understand his pupil’s individual needs and character could probably dispense with it: “I will content myself with saying that children are helpless and easily victimized, and that therefore no one should be given unlimited power over them.””
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