If you’ve seen the 20006 TED talk of Hans Rosling, “The best stats you’ve ever seen”, you’re already familiar with the topics of the book Factfullness. There’s of course more material in the book than in the talk.

I took the following take-aways from the book:

Our mental model of the world may be wrong in significant ways

This is the main theme of the book. Rosling shows with several quizz that our knowledge of the world is very imprecise, if not wrong or outdated. As a consequence we have a wrong model of the world, its problem, but also possible solutions. He offers several explanations for this, like our bias for sensational news that misrepresent the state of the world.

Rosling was an expert in global health, so many quizz are about population statistics, e.g. “what is the percentage of vaccinated children worldwide”. He shows that many people underestimate how the quality of life changed in the last decades.

There are various levels of “poor”

When it comes to income levels, here again, our model of the world is too simplistic. Instead of categorizing countries in poor or rich (or developped and developping), Rosling proposes four levels of income. He then shows how life is for these levels – from extreme poverty to “western” rich. I guess I’ve only travelled to places corresponding to level 4 and 3.

The project dollar street that Rosling launched is a website where you can browse families worldwide to see “how people really live”. It’s worth having a look.

It takes many policies to improve the world

Hans worked in global health. The standard of living we have know has only been achieve because many policies have been put into place over decades: vaccination campains, access to clean water, practices in hospital, road safety practices, etc. The average life time is the best metric to figure out the progress. The topic is brought vividly in the book with Hans almost drowning as a kid. Now, such an area would be proctected with fences for small kids.

Focus on individual vs. focus on population are both valid choices

There is an interesting section in the book showing the following dilema: should you put your effort to improve life in a population in average, or should you focus on helping the most the specific patients that come to you? There is no right or wrong position. Bur for Rosling, it was clearly about focusing on the macro perspective.

Put numbers in context

I loved this chapter of the book. Don’t be impressed by numbers alone – small or big. They tell nothing. You must always put them in context.

You need to periodically refresh your world views

The facts you learned 10 years ago aren’t acurate anymore. You need to update once in a while your knowledge.

The domain of Hans was global health. But I can easily find parallel for these take-aways in other domains. For instance, software quality in the software industry has improved thanks to best practices like version control, pair programming, unit testing, etc. This is much like policies in global health. It takes decades to change company cultures and see benefits at the level of the industry.

About outdated world views, I can easy come with examples in the sector of energy, since I have recently read “Energy and civilization“. In this book, I learned about the the fracking revolution and that the USA become major producer of natural gas after 2001. My world view was stuck in the narrative of that time.

One striking example in the book of a poor model of the world was the question related to population growth. How bigger will the populationi in 2100? As countries develop, the number of children pro family tend to reach 2, making for a stable population. Many countries have already reached this ratio, more than I thought. Using the projected development of countries with a high ratio, it turns out that the projected population growth from the UN is 11 billion people in 2100 (7.8 billion in 2020). We will have to accomodate 50% more people on earth.

If you think about ist, it’s one of the most important fact to know about the world to understand where the world is heading. If we want to find solutions to climate change and other challenges, we need to have an idea of the population we have to sustain. But I wouldn’t have been able to estimate the population before reading the book.

The book made me more aware that our model of the world may be wrong and that our intuition often fails.