Fairly early in the pandemic it was widely accepted in scientific circles that the likelihood of outdoor transmission of Covid at low-density events — say garden parties or beer gardens — was relatively low.
It might therefore have seemed logical to allow such gatherings to take place sooner than we did. From a practical point of view, however, it could have been a terrible move. As is so often the case, a straightforward scientific finding does not always translate into practical legislation. Like the saying goes: ‘In theory there is no difference between theory and practice, but in practice there is.’ In reality, policy-makers cannot simply follow the science: there is always something else at work.
Here two confounding factors are human behaviour and weather. Had we allowed socialising in gardens, it is likely many such events would have continued into the early evening when it began to get cold. Or, this being Britain, it would have started raining. There is also social convention to contend with: few men and fewer women are content to pee in any garden smaller than an acre. (The acre is a medieval unit of area denoting the minimum size of a plot of land in which it is always permissible to urinate.)
What this means is that, at some point in any outdoor party, two party-goers would inevitably have moved, shivering, to the conservatory, and five more would have needed the loo. An hour later, following a general migration indoors, what started as an outdoor gathering would have morphed into an indoor superspreading event. Something like this seems to have happened at the White House. Any garden party is effectively a house party in the making.