When you are a 'big person', residing at the top of the human food chain, totally engaged in the concept of an ever upward Progress, you tend never to look down at the complexity of Life below your feet.
Partially it is your class and ethnic snobbery about all the 'lesser breeds', partly its a popular scientific construction that the smaller and the older simply must be 'less progressive' and hence just ancient history.
None of this is possible when you are a 'small person' , at the bottom of the human food chain, also eternally looking upwards.
Looking upwards isn't a luxury for the small and the weak - they need to see all the warning signs of potentially trouble from their bosses ('betters') as soon as possible, if they are to survive.
And when you are on the bottom, everybody else is your boss and your 'better' --- you can't help but appreciate just how varied and complex the human world actually is.
If Henry Dawson saw the world different than his contemporaries , as vastly more complicated than they saw it, perhaps he had cause ...