I would agree that Freud's emphasis on the unconscious had a dramatic effect on the way Europeans thought about humanity. I would also argue that a unique form of nationalism, influenced by social Darwinism, took root during this period as well. This way of thinking encouraged colonial acquisitions, cast foreign relations as an eternal (and noble) struggle, and had the dangerous effect of motivating smaller nations, like Serbia, to struggle for regional dominance, and bigger nations, like Austria-Hungary, Germany, and Russia, to involve themselves in their struggles. It also encouraged a new spirit of militarism that emphasized martial prowess as an indicator of masculinity. We all know how it turned out in the second decade of the 20th century.