“ The 9-month-old babies were better able to recognize faces and emotional expressions of people who belong to the racial group they interacted with the most. At this age, babies have developed a racial bias, meaning they becoming more skillful at telling apart two faces within their own race. The brain activity of these group of infants showed specific pathways had been reinforced by practice decoding familiar faces, while other less-used pathways were not.”
Long story short: babies as young as five months prefer people who are the same color they are. Know why? Because diversity is artificial and stressful.