Time, Plans & Workload

In the 1970s, the psychologist Daniel Kahneman had an idea: a school textbook that teaches teenagers how to think and make decisions. He convinced the Israeli Ministry of Education, put together a small team and became responsible for the whole project. Every Friday afternoon they met and worked. After a year, they had an outline, a few chapters and some test lessons. Everyone felt proud.

Then Kahneman asked a simple question: “How long will the rest take?” Each person wrote a number on a piece of paper. The answers were between one and a half and two and a half years. Every estimate was aligned with the others, and every one of them was wrong.

Next, he asked Seymour, the team's expert on school programmes, how long similar teams had needed. Seymour went quiet. Then, a little embarrassed, he said that about 40% of such teams never finished, and the others needed seven to ten years.

For a moment, the room was silent. Nobody wanted to deal with that information. After a short, gloomy discussion, the team did something very human: it carried on as if nothing had happened. Yes, a team writing a textbook about good decisions made a bad one. They stayed committed to the plan and relied on their feelings, not on the facts.

The book was finished eight years later. By then, Kahneman lived in another country, there had been a big drop in interest at the Ministry, and the textbook was never used. The impact on the team's lives was enormous: eight years of Fridays for nothing.

Kahneman called this the planning fallacy: we imagine the best possible story for our project and forget how similar projects ended. His advice? The key to a realistic plan is to look at similar projects first. And nobody on that team ever tried to adapt to what Seymour had told them.