Different similarities

The problem with complex evolved human brains is that two people can look at the same scene and interpret it in two entirely different ways depending on the particular wiring of their respective neural networks; as determined by genetics, upbringing and education etc. Brains are "plastic" like this, they develop in an infinite number of subtle ways and even the exact same input stimuli (sights, sounds, smells etc.) prompt entirely different responses, no two brains are the same. More often than not this variation is something to be celebrated and enjoyed, after all, it's the basis of creativity and learning to which our greatest achievements as a species can be attributed.

However, when it comes to deciding important policy that affect other people's lives in significant ways it's clearly desirable (from the perspective of the people the decisions affect) for decision makers to approach the evaluation of the options from an objective perspective rather than a subjective one. Unfortunately, that's a hard thing for evolved brains to do and requires significant effort and training; shedding our biases even for a short while is difficult. Sometimes deeply held views can seem so concrete, so immovable and so compelling that not only would people rather die than abandon them, they would also rather die than simply examine them critically. Even people who claim to be "rational" often fail to grasp this basic human trait, they don't (and are often unable to) see themselves as others see them. Facts and ideas become blurred and interchangeable, in-groups become intellectual echo chambers that simply reinforce established dogmas, and nothing from the outside can penetrate and influence.

Take a look at the picture above, two people who are genetically related and almost certainly share more traits and behaviours than they are probably even aware of. Both love their mum and dad, feel pain, digest food, appreciate beauty, fancy Justin Bieber, bleed red when cut and both would claim that their positions are rational and "true". Yet for the rest of us in theological no man's land these two intellectual positions remain diametrically opposed; two people who may even think that they would rather kill or die than abandon their deeply held beliefs.

Then imagine being an alien crossing the vast expanse of space for a million years to land on Earth with no pre-knowledge about any of the historical, cultural or theocratic underpinnings of these two world-views.

Could they tell the difference?