Revisiting the Population Pyramid

This discussion reemerged earlier in the week, following an earlier discussion when it was first tweeted by Kit Marie Rackley back in January. This time round I thought I'd follow up a little as I have the time.

One thing to say at this point is that I may, as a cis person not necessarily be the best person to come up with a solution to this issue, but here are some thoughts as a response to the original query.

Population pyramids are defined as follows:

A population pyramid is a way to visualize two variables: age and sex. They are used by demographers, who study populations. A population pyramid is a graph that shows the distribution of ages across a population divided down the center between male and female members of the population.

I discussed this with my students at the time of the original tweet to see if they could spot some of the problems with this technique of showing demographic data.

They noticed that only male and female were represented and also that they were often shown by blue and pink colours.

How could another group of people be represented, and actually would it be enough to just have one extra set of graphs for those who were non-binary?

This is an important aspect of the recent census. This report outlines the development of a question for the Scottish Census in 2021. (PDF report)

There were separate questions for Sex and Gender on the UK Census.


The Sex question was compulsory, the Gender question was voluntary.




Sex is a protected characteristic as set out in the Equality Act 2010.
Here are the Protected Characteristics


One issue with creating a population pyramid is that it requires data, and there would be few countries where the data existed to be able to create an alternative pyramid until the next time a Census is held which allows the data to be collected appropriately so that these can be separated. 

At the moment, the sex that is used for the data is measured at birth. One would imagine that decisions about the sex that individuals identify as would come later.


Cis, short for cisgender (pronounced sis-gender, or just sis), is a term that means whatever gender you are now is the same as what was presumed for you at birth. This simply means that when a parent or doctor called you a boy or a girl when you were born, they got it right.

It would be possible for parents to avoid making a choice of sex, but more likely that everyone who identifies as transgender or some other identity was either a 'boy' or 'girl' when their sex was assigned, other than small numbers of exceptions such as intersex people. 

We also need to consider that what we are thinking about is an alternative age-sex pyramid and not an age-gender pyramid. 

Or perhaps it is time to rethink whether these diagrams are fit for purpose?
What are they for? What geographical processes do they attempt to illustrate, and would they be better served by an age-gender pyramid. 

There would also be some countries where the collection of such data would not be considered, because identifying in particular ways would be illegal or not even considered.
How can there be a comparison made between countries when such identities are outlawed in some of them?


The Census 2021 included a question on gender for the first time and was quite controversial to some groups of people. A lot of time was taken over the wording.


Once the data has been extracted and 'processed' in the usual way, it will be interesting to see the outcome and whether this will have an impact on thinking in this area. Perhaps when the data are available it will be possible to attempt creating some alternatives.

Finally, an interesting National Geographic visual on annotated population pyramids with age groups such as Gen-X and Gen-Y etc.
There are some other issues with the technique as well, which are explained here.

All comments welcome. 

The lack of much coming up on a web search suggests this is an interesting area that hasn't received a lot of attention.

Thanks to Kit Marie Rackley for comments on a draft of this post ahead of publication.

Also keep an eye out for some new and forthcoming GA CPD in the area of EDI which Kit is involved with.

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