Pet ideas, hidden assumptions and the ability to hold two things at once

Kill Your Favourite Idea is the most uncomfortable exercise in the course. It is also the one with the deepest theoretical support.

The pet idea problem

Griffiths identifies selective thinking — validating certain ideas and discounting others, typically our own favourites — as the single aspect of human thinking that causes the most harm in brainstorming and decision-making. He connects it to confirmation bias and quotes Chartier's warning: nothing is more dangerous than an idea when it is the only one we have.

The danger is not that the favourite idea is bad. It is usually decent, which is why it became the favourite. The danger is that its presence stops the search. Once an idea occupies the position of "the idea", every subsequent thought becomes a variation on it, and the team experiences this as thinking freely.

Removing it temporarily is therefore not an exercise in humility. It is a method for restarting a search that quietly stopped.

Assumptions, conscious and otherwise

Adair's chapter on testing assumptions supplies the distinction the exercise depends on. Assumptions made consciously, deliberately and temporarily are a legitimate tool — his image is making a move in chess while keeping your hand on the piece. Assumptions made unconsciously are hidden sandbanks outside the harbour mouth: you do not see them until you are aground.

His instruction to teams is the one most relevant here: welcome others when they challenge or test your assumptions. A team in which nobody challenges the concept is not harmonious; it is navigating with the sandbanks unmarked.

It is worth knowing that the phrase everyone uses for this comes from him. Adair introduced the nine-dot problem in 1969, and reports that the phrase "think outside the box" derives from it.

The same chapter contains the discipline that makes challenge productive rather than destructive: suspending judgement, which he defines as a temporary barrier between analysing and synthesizing on one side and valuing on the other. During the rebuild phase of Kill Your Favourite Idea, that barrier is what stops the team from dismissing each alternative in the second it is proposed.

Groupthink and the devil's advocate

Janis's account of groupthink, reported by Dawson and colleagues, is the team-level version of the pet idea. Cohesive, friendly groups suppress dissent in the drive for consensus; alternatives go unexamined; expert opinion is ignored or read selectively. The result is a deterioration in the group's capacity for reality-testing.

Among his prevention steps, three appear directly in this lesson's design: assign someone the devil's advocate role to surface unfavourable outcomes; periodically split into subgroups to gain a fresh perspective; and re-examine the plan for flaws once the decision has been reached. That last one is exactly what Kill Your Favourite Idea does — it re-opens a decision the team believed was settled.

Janis also advises that leaders should expect and invite criticism of their own positions. This is why the lesson advises that whoever holds the most authority should kill their own favourite first. If the exercise begins with a young member's idea being removed, it demonstrates hierarchy rather than flexibility.

Exploration and exploitation: the ambidexterity problem

The deeper theory behind "firm on mission, flexible on method" is the tension James March identified between two activities that both need doing and interfere with each other.

Exploitation hones and extends current knowledge, seeking efficiency and improvement — it produces incremental innovation. Exploration develops new knowledge and experiments to create the variation and novelty needed for more radical innovation. Dawson and colleagues note that organisations must excel at both to survive: catering to current demands while creating the future.

The two pull in opposite directions. Exploitation rewards consistency, refinement and doing more of what works. Exploration rewards variation, risk and abandoning what works. An organisation that is good at one is usually bad at the other, and this is why ambidexterity is treated as a genuine capability rather than a slogan.

Rosing and colleagues, cited by Dawson, argue that firms facing these contradictory demands need an ambidextrous leadership style that fosters both explorative and exploitative behaviours — increasing or reducing variance in people's behaviour and flexibly switching between the two. Their reasoning is that innovation is complex and unpredictable, and the generation and implementation of ideas are not organised in a neat sequence.

Clapham and Meyer's review adds that ambidextrous leadership — guiding a team as it switches from experimentation to implementation — is positively associated with innovation at work, and highlights the importance of leaders who model agility and flexibility.

This is directly usable. Early project weeks are exploration; later ones are exploitation. Kill Your Favourite Idea is a deliberate, scheduled return to exploration inside an exploitation phase — and whoever is facilitating has to signal that switch clearly, because nobody can do both modes at once by accident.

Why efficient teams become rigid

The practical lesson claims that a team optimised to do one thing smoothly cannot do a slightly different thing. Dawson and colleagues supply the organisational version: the norms that promote creativity (risk-taking, tolerance of mistakes, continuous learning, constructive conflict) are different from the norms that promote implementation (teamwork, speed and urgency). A team that has fully adopted the second set has, without deciding to, stopped being able to run the first.

The same authors also examine whether strong, cohesive cultures can hinder innovation and change — and the answer, consistent with Janis, is that they can. Cohesion is an asset up to the point where it starts suppressing dissent.

Adair adds the individual version: some social climates encourage and stimulate creative thinking while others stifle or repress it, and a team's climate is something it produces rather than something it has.