Want more diversity? Hire groups, not individuals

If I were to give you a budget to choose your perfect house, you would quickly have a clear idea of what to buy. And typically your perfect house will be a bit boring. That’s because, when you can only have one house, it cannot be too weak in any one dimension. It cannot be too small, too far from work, too noisy or too weird. So you’ll opt for a conventional house.

On the other hand, if I were to double your budget and tell you to buy two houses, your whole pattern of decision-making would change. You would now be looking to buy two significantly different properties with complementary strengths — perhaps a small flat in a city and a house in the countryside. Your criteria for the two houses would be wildly different. Neither would be the one you had chosen as a single home.

We know this instinctively in the domain of houses. Or cars. Nobody would buy four identical cars. One person choosing four things isn’t the same as four people each choosing one. Yet, intriguingly, in other realms of decision-making we seem not to understand this at all. For instance, in assessing job applicants or parliamentary candidates or university admissions, no one gives any thought to this effect. It is assumed that ten groups each choosing one candidate will make the same ‘optimal’ choice as one group choosing ten. They won’t.

If you are choosing a single parliamentary candidate, the safe default option is to pick a vapid but presentable PPE graduate. Yet no one choosing ten people would choose ten of those. They might choose two or three, but they’d also throw in a few wild cards — maybe someone who’d had a proper job, a woman, someone from a poorer background and someone with a science degree.