Public bodies often use graphics to show an inclusive set of characters representative of the community. For example...
But if you were trying to be precisely representative, what should those characters look like? For example, if you were trying to create six characters representative of the UK, what genders, ages and ethnicities should they have?
Let's start with an easier problem - one character.
That one character should be female, because there are fractionally more females (50.6%) than males (49.4%). She should be 39, because that's the median age of a Briton. And she should be white because most Britons are.
female
39
white
Next, what about two characters?
Gender is easy, there should be one male and one female - an almost perfect match. Admittedly some people identify as genders other than male and female but, at this macro scale where each character represents 50% of the UK population, small percentages don't matter.
As for age, we need one character representative of the youngest half of the population and one representative of the oldest half. In statistical language we need the lower and upper quartiles of the UK's age distribution. Checking the latest data, one should be 20 and one should be 58.
And as for ethnicity they should both be white. Over three-quarters of the UK's population is white, so if we only have two fictional characters to play with, the most representative case is that both are white.
male
20
white
female
58
white
n.b. Yes, the female could be 20 and the male 58, but let's not worry about that.
n.b. If you wanted the characters to be representative of the adult population, i.e. no under 18s included, then the relevant ages would be 32 and 63. But let's not go there.
Now let's jump up to six characters.
Three male and three female, that's easy.
As for ages, we need to split the population into sixths and then find the middle of those sixths. That gives ages of 6, 20, 33, 46, 58 and 74.
As for ethnicity, this may not be what you're expecting. At the last census the proportion of white people in the UK was 87%, which is almost exactly five-sixths, which means five of the six characters should be white. As for the remaining 13% of the population, 7% are Asian, 3% black, 2% Mixed and 1% Other. And 7% is just over half of 13%, which means our sixth and final character should be Asian. There'd need to be over a dozen characters in our graphic before the first one was black.
male
6
white
female
20
white
male
33
Asian
female
46
white
male
58
white
female
74
white
What's intriguing is whether London's set of six characters would be different.
Three male and three female again, obviously.
But the ages would be lower, at 5, 19, 30, 39, 51 and 70. The average Londoner is five years younger than the average Briton.
As for ethnicity, the percentages for London are white 60%, Asian 18%, black 13%, mixed 5% and Other 3%. That means four of our six characters would be white, one Asian and one black. I suspect that's still whiter than you were expecting. Digging deeper one of those four white people is probably Eastern European, but you'd not be able to tell that from a simple graphic.
male
5
white
female
19
Asian
male
30
white
female
39
white
male
51
black
female
70
white
So why don't sets of characters in graphics look like this? Why are the ethnicities depicted more diverse than they would be in real life?
It's because they're not trying to be representative, they're trying to be inclusive. If you're white you don't need to see several white characters, you need to see at least one, and the same for Asian and black citizens. We don't expect groups of characters to reflect the population, we look to see ourselves.
For example, this covers most bases in just three characters.
female
13
black
male
39
white
female
66
Asian
Even if there's nowhere in Britain which actually looks like that.