Faces changed, yes, and researchers think diet may have played a role:
The changes in human heads over the past 160,000 years were not driven by a changing brain, researchers say. It was the human face that changed, according to a recent article at New ScientistNews, “Human brain shape hardly changed in 160,000 years” at Mind Matters News (August 5, 2022)
Takehome: The human brain reaches 95% of adult size at six years of age. Interestingly seven years of age is commonly held to be the “age of reason.”
You may also wish to read: You may also wish to read: Researchers still puzzled: Why did human brains shrink? Human brain volumes decreased by 10% in the last 40,000 years, coinciding with spectacular intellectual achievements. Examples of brain shrinkage among animals are fascinating but have not provided much insight. But perhaps we should ask, how much does brain size even matter?