The king and his men marched to Jerusalem to attack the Jebusites, who lived there. The Jebusites said to David, “You will not get in here; even the blind and the lame can ward you off.” They thought, “David cannot get in here.” – 2 Samuel 5:6

Today’s Scripture Reading (April 8, 2019): 2 Samuel 5

The Overconfidence Effect is a well-established bias that indicates that sometimes we have too much confidence in our behavior and not enough confidence in the actions of others. Fundamentally, because of an overconfidence bias, we think we have a better chance of attaining to specific goals or possessing certain knowledge than is actually true. The immediate effect of an overconfidence bias is that we decide not to put the effort required into specific tasks because we falsely believe that we have every variable in hand. The Overconfidence Effect is a universal problem, and all of us fall prey to it at one time or another.

One type of overconfidence bias is the “Illusion of Control.” Specifically, the “Illusion of Control” is a type of overestimation bias. It is the false belief that we have all the elements of a situation under our control. There is nothing that we have missed. The events that surrounded September 11, 2001, to a certain extent, are an example of this type of bias. When the planes crashed into the Twin Towers in New York, and into the Pentagon in Virginia, there was genuine surprise and terror in the hearts of many people, even in those who existed at the top of political power. We didn’t think that anyone could take control of planes and then successfully drive those planes into buildings. When the first plane crashed into the North Tower, the first reaction among many was that there had been a terrible accident, and not a planned attack. We thought we were in control, but it quickly became apparent that we were wrong.

As David marches toward Jebus or Jerusalem, a city in the midst of Israel that had never been under Israelite control, the Jebusites living in Jerusalem suffered from the Overconfidence Effect; specifically, they suffered from the “Illusion of Control.” The Jebusites strongly believed that they were safe. The evidence for that conclusion was the fact that an Israelite army had never been able to take the city. Centuries had passed, and the walled city, built on a hill, had never suffered defeat. The question that raged inside the city walls was “why would this time be any different.”

Jerusalem had everything that a city needed to withstand a siege. It had high walls, strong enough to repel any attack. It also had a source of fresh water inside the walls to keep the people alive. These things, among others, had served the city well in the past. And as far as the Jebusites were concerned, they would serve the city long into the future, well past the time of this temporary King on the throne of Israel. David might be a mighty warrior, about whom songs have been sung, but in Jerusalem, warriors were not needed to defend the city. In Jerusalem, the blind and the lame could fight him off. David and his army did not stand a chance against the city’s fortifications.

But David was determined to take the city. And in the end, a water shaft was all that was needed for David to get behind the ‘blind and lame’ warriors defending Jerusalem. It was a small weakness, easily secured, but overlooked by the overconfident Jebusites.

Tomorrow’s Scripture Reading: 1 Chronicles 11