In a journal article titled, Overconfidence in Case-Study Judgements, Stuart Oskamp asked a group of doctors and students to provide correct answers to a series of questions about a real person nicknamed ‘Joseph Kidd’.
The information about Joseph Kidd was presented in 4 stages, with questions asked after each stage. In addition to providing correct answers, participants were also required to answer how confident they were about their answers.
Stage 1 contained brief demographic information about Kidd like age, gender and so on.
Stage 2 had information about Kidd’s childhood.
Stage 3 contained information about Kidd’s education.
Stage 4 had information on other activities that Kidd was involved in till he clocked 29 years.
In all, the participants were asked 25 questions about Kidd.
On average, no one (even the doctors) got up to 30% of the questions right.
Yet, in spite of the poor accuracy of their answers, the more information a participant had about Joseph Kidd, the more confident they were in their answers. And there was no difference between the doctors and the students!
My key takeaway is something I’ve nearly flogged to death.
More information doesn’t necessarily translate into better decision-making.
That’s why I’ve stressed countless times that you don’t need to know everything. You only need a revealed knowledge of what works and the wisdom to work it out.