What is interesting to me here is not just the scientific aspect of this, which is great (I love anthropological universals), it is the philosophical aspect relating to Platonism. The innate geometric knowledge is not due to the pre-existence of our soul in the realm of the forms, as Plato thought.
Instead it is due to one or both of two things: 1) it is due to the universal experiences we have as creatures acquiring knowledge in a common spatial environment; or 2) it is due to a “pre-existence” of our genes – selected for these geometric abilities – in the evolutionary/historical “realm” of our ancestors, genetically passed on to us and thus giving us these selected-for capabilities as well. That possibility boggles my mind. The past/pre-existence does live on in us – the Platonic realm of the forms is the genetic memory of our ancestors. Plato updated with science.
In both cases evolution has set us up as a species to have these common shared intuitions, but in the first case we are just predisposed to learn these things, while in the second case the intuitions themselves are actually innate. Good experiments in child psychology might be able to tease these apart and show us which it is (or both).
How’s this relate to ethics? As with geometry, so with morality. That’s still controversial (to some people), but the evidence is growing.