Congenital moles at birth
Approximately 1% of babies are born with congenital moles, which vary widely in color, size, and whether they have hair.
Snapshot · Stuff You Should Know
Selects: Birthmarks: Probably Not the Mark of the Devil
Explore episode
Jun 20, 2026
Where this was said
Mongolian Spots and Moles
At 29:05 · chapter starts 28:15
Chuck describes Mongolian spots: bluish-gray marks typically on the lower back and buttocks of African, Asian, and Hispanic babies that can easily be mistaken for bruising by uninformed observers. They're clusters of deep pigment cells, not blood, and usually fade by ages 6–7. The hosts then move to moles, distinguishing between congenital (born with it, ~1% of babies), acquired (developing later, often from sun damage), and atypical (irregular, multicolored, associated with melanoma risk). Josh notes that virtually all congenital moles have some hair, a fact he credits to the Dollar Shave Club blog. The acquired vs. congenital distinction also raises the philosophical headache of what counts as a birthmark — a loophole that keeps frustrating both hosts.
Mongolian spots fade by age 6–7
Mongolian spots, bluish-gray birthmarks common in African, Asian, and Hispanic children, usually fade by ages 6–7 and can be mistaken for bruises.
Atypical Moles: The Warning Sign Most People Ignore
Atypical moles are the ones you want a doctor to examine — they're amorphous in shape, have color gradients, and are associated with melanoma. Most people don't take melanoma seriously, but it can spread through the body faster than almost any other cancer.
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