As a hobby I collect bad arguments. One I have seen of late surrounding some really shitty and poorly reasoned comments by J K Rowling about gender, is an attempt to pretend that exceptions to the basic chromosomal binary sex classification (i.e. the high school text book simplification of XX & XY) don’t matter. It’s a fallacy we can call the low-percentage fallacy and it is not just present in TERF-pseudologic but in arguments about disability, minority language groups, ethnicity or religion. Essentially the idea is that if a categorical scheme works 99% of the time then voila! They have established some kind of platonic truth where the very real exceptions (which really do matter) don’t count even if the person making the argument concedes they exist.
Proportions need context. If we are talking social policy (and despite often chasing into the weeds of reproductive biology the Rowlingesque arguments are about social policy) then social context matters. A very basic context for a figure like 1% is one-percent of how many people?
For reasons nobody is entirely sure about, the UK is currently an epicentre of spectacularly bad reasoning of Rowling kind. So let’s use the UK as a context. The population of the UK is 66.65 million people and England is 53 million. 1% of 66.65 million is 666,500 or a bit over 6 hundred thousand. For further context the population of the city of Manchester is 510,746 (that’s not Greater Manchester just the city proper https://en.wikipedia.org/wiki/Demography_of_Greater_Manchester )
We can use the low-percentage fallacy to make Manchester disappear in a Thanos-like click of my arithmetic fingers. Less than 1% of English people live in Manchester, so we can assume PEOPLE DON’T LIVE IN MANCHESTER. Do we need railway stations in Manchester? No, because nobody live in Manchester. How about the M62 motorway which connects Liverpool (where also nobody lives) to Manchester and then unto Leeds (where also nobody lives) and the rest of Yorkshire (where some people live but only if we aggregate* them enough)? Obviously a huge waste of time and money BECAUSE NOBODY LIVES THERE.
Why on Earth Manchester has not one but TWO football teams is a mystery as, again, nobody lives there (although most Man U fans really don’t live there…) Also, of the people who don’t live in Manchester, none of them are called Smith. It’s true! English people aren’t called Smith even though it is the most common surname in England (OK at 747,967 it just creeps up to 1.1% https://britishsurnames.co.uk/surname/smith/stats ). Weirdly, red haired people do exist in the UK but by the percentage-fallacy don’t exist in the human population.
It’s not just bad reasoning but it is a kind of error you see in some gee-whiz claims about AI algorithms that are “99% accurate”. It is also has a highly sinister aspect when considering minority ethnic groups in many countries, where groups who are proportionally small can be vanished from policy consideration despite amounting to hundreds of thousands of people. If the Aboriginal and Torres Strait Islander peoples of Australia were a city (798,365 people in 2016 https://www.aihw.gov.au/reports/australias-welfare/profile-of-indigenous-australians ) they would be the sixth largest city in the country (https://en.wikipedia.org/wiki/List_of_cities_in_Australia_by_population).
*[Also don’t aggravate people from Yorkshire.]