8 January 2025

Imagine a society in which all the mothers become pregnant around the same time and, when it’s time to give birth, they all gather in a large room and give birth on the same night. It’s dark, there are lots and lots of babies. All the women help each other and help the babies. Soon no one is sure which baby is her own biological child but it doesn’t matter because all the mothers raise the young together. In the shuffle each mother finds a baby she wants to cuddle and care for and that child, regardless of whether it’s the one she birthed, is the one she will escort into adulthood.

That’s a pretty good description of banded mongoose (Mungos mungo) society.

Because of their birthing strategy banded mongoose moms are confused about biological kinship. Does this lead to a fairer society? Do the best equipped mothers cuddle the pups who need the most care?

In 2021 scientists from the University of Exeter and the University of Roehampton decided to find out. In their paper at Nature Communications: A veil of ignorance can promote fairness in a mammal society, they wrote (paraphrased), “In his 1971 book A Theory of Justice, American philosopher John Rawls argued that fairness in human societies can be achieved if decisions about the distribution of societal rewards are made “from behind a veil of ignorance” which obscures the personal gains that result.

Working with seven groups of mongooses in Uganda, they manipulated the birth weights of pups by giving some, but not all, of the pregnant mongooses extra food. After giving birth, the well-fed mothers doted on the smaller pups born to the underfed mongooses by feeding, carrying, protecting, and grooming them more often than their own, larger pups. “

We predicted that a ‘veil of ignorance’ would cause females to focus their care on the pups most in need” rather than their own offspring, Exeter evolutionary biologist Michael Cant said in a press release. In doing so, he adds, mongoose mothers minimize the risk that their future offspring could one day face a disadvantage—while evening [leveling] the playing field for the whole colony.

— Science Magazine, June 2021: Mongoose mothers help their colonies thrive—by forgetting which pups are theirs

Confuse mongoose moms about kinship and you get a fair society.

p.s. Banded mongooses are closely related to meerkats. This one poses like a meerkat.

And here’s where banded mongooses live.