The minute a man stops supplicating God for His Spirit and direction, just so soon he starts out to become a stranger to Him and His works. When men stop praying for God's Spirit, they place confidence in their own unaided reason, and they gradually lose the Spirit of God.
Icelandic people are inbred. And they have a sense of themselves as genetically special, and a history of risk-taking because they make their living on the high seas fishing. Assets generally rose in value during this period, and so it looked like they actually knew what they were doing.