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On August 15, 1939, Britain’s Government Code and Cypher School moved to a country estate north of London: Bletchley Park. A few weeks later, on the day Britain declared war, its head, Alastair Denniston, wrote to the Foreign Office. He wanted to recruit “men of the professor type.” The first came from Oxford and Cambridge. In January 1945, 8,995 people were working at Bletchley and its outstations. An example of the Team Principle of Diversity.
Professors, Chess Masters, Puzzle Solvers
Situation
The recruits included mathematicians, linguists, classicists and chess masters. Dilwyn Knox, an expert on ancient papyri, led a section working on variants of the Enigma. The mathematicians Alan Turing and Gordon Welchman designed the “Bombe,” a machine that worked through possible Enigma settings. Hugh Alexander and Stuart Milner-Barry were chess masters. In 1942 even a crossword competition in the Daily Telegraph helped with the search: those who solved the puzzle in under twelve minutes received a confidential letter and were invited to an interview. Several people came to Bletchley this way.
Connection to the team principle
The Team Principle of Diversity states: differences only make a team smarter if it puts them to use – otherwise they split it. Bletchley wasn’t after diversity for its own sake. The task was new, and no one knew which way of thinking would crack it. So they brought in several: formal reasoning, a feel for language, pattern recognition, patience with puzzles. The diversity followed the task.
Huts as a Chain
Situation
The work was organized by huts. Hut 6 broke the Enigma messages of the army and air force; Hut 3 translated and analyzed them. Hut 8 worked on the naval Enigma, Hut 4 on its analysis. Codebreakers and linguists worked as a chain: what one group made readable, the other had to understand and put into context.
Connection to the team principle
This is the heart of the matter. Different specialists in the same building do not yet make a team. At Bletchley, the workflow was built so that no link could produce a result without the other. A decrypted message without a translation was worthless; a translator without decrypted text had nothing to do. The organization forced the differences into collaboration. This fits a research finding: a meta-analysis by Hans van Dijk, Mariëlle L. van Engen and Daan van Knippenberg (2012, 146 studies) found that job-related diversity is linked to better performance mainly on complex tasks and in innovation. Across all tasks, by contrast, the effect of diversity is small.
A Letter to Churchill
Situation
In 1941 Bletchley was short of staff. Turing, Welchman, Alexander and Milner-Barry – two mathematicians and two chess masters – wrote jointly and directly to Prime Minister Winston Churchill. Churchill’s order, in essence: give them what they need, with the highest priority, that same day.
Connection to the team principle
The four came from different disciplines and acted together. That shows how far the bond reached: the boundaries between disciplines had not hardened into camps. And it shows the role of top leadership. A team that puts its differences to use needs backing and resources.
Student of German, Engineer, Mathematician
Situation
In December 1941, Mavis Lever, a student of German, broke a message that revealed the wiring of the Enigma used by the Abwehr, Germany’s military intelligence service. On May 25, 1941, Jane Fawcett decrypted a message on the position of the battleship Bismarck; two days later it was sunk. The mathematician Bill Tutte and colleagues worked out the structure of another German cipher machine without ever having seen it. To break it, Post Office engineer Tommy Flowers built Colossus, the first programmable electronic digital computer.
Connection to the team principle
The breakthroughs came from different directions: from a language student, from a mathematician, from a Post Office engineer. None of them could have done the others’ work. Diversity put to use means that every perspective gets a problem on which it can prove itself.
The Limits of Diversity
Situation
About three-quarters of the staff were women, many from the women’s auxiliary services of the navy, air force and army. They were rarely given codebreaking posts. Joan Clarke was one of the few women who worked as a full-fledged cryptanalyst. The work remained secret until 1974; official recognition came only in 2009.
Connection to the team principle
Bletchley made far better use of the differences between disciplines than of the talents of the majority of its workforce. Even a role model has blind spots. For you, this raises an uncomfortable question: Which abilities exist on your team but are never called on because of role or habit?
Key takeaways
Key Lessons
- Derive the team’s composition from the task. Ask: Which ways of thinking does this problem need – and which are we missing?
- Build workflows in which the disciplines need one another. Handovers, joint reviews and shared results connect people more than any team-building day.
- Look for talent in unusual places. At Bletchley, a crossword puzzle served as a selection process.
- Secure backing from the top. Mixed teams need more time and resources at the start.
- Check who on your team can do more than their job requires.
Summary
Bletchley Park brought together mathematicians, linguists, chess masters and engineers and organized their work as a chain in which each group depended on the others. The breakthroughs came from very different minds. At the same time, a large share of the talent – that of the many women – was used far below its potential. Here the Team Principle of Diversity shows itself in both directions: differences pay off only where the task and the workflows actually put them to use.