40% of our happiness is determined by our internal state of mind. Or in other words, 40% of our happiness is within our control.
A brand new survey of 1,155 respondents found that on average, people judge that 40% of their happiness is a result of their internal state of mind.
For some of you, this 40% statistic may sound familiar. The 40% statistic was first published in the paper ‘Pursuing Happiness: The Architecture of Sustainable Change‘ in 2005. This statistic has become especially popular after the release of the book “The How Of Happiness” in 2007.
In the meantime, this statistic has never been updated, despite receiving some criticism here and there.
Our study dives into the questions that come with a statistic like this. What type of people are inclined to feel more internal happiness than others? How does that actually influence the happiness of these people?
- 40% of our happiness?
- What causes the deviation within our dataset?
- This study supports the 40% statistic
- How was the 40% originally determined?
- Closing words
40% of our happiness?
Our survey questioned 1,155 respondents on their happiness, by asking a very specific question:
If you look back at the last year of your life, how much of your happiness was dependent on genetics, circumstances and your internal state of mind?
Each of the 1,155 respondents provided answers based on a range from 0 to 100%, with intervals of 10%.
(A footnote was added that reminded respondents that the total of all 3 factors must add to 100%. When the total didn’t match 100%, the individual factors were scaled up or down pro-rato, so that the total would match 100%.)
The 1,155 answers are presented in a histogram below:
The average of the dataset is exactly 40%, with a standard deviation of 14%.
This means that the remaining 60% of our happiness is determined by either our genetics or external circumstances.
This 40% of happiness that comes from our internal state of mind exactly matches the statistic that was originally proposed in the paper ‘Pursuing Happiness: The Architecture of Sustainable Change‘.
What causes the deviation within our dataset?
With a standard deviation of 14%, we wanted to determine if there were certain factors that could reliably influence the amount of happiness that is determined by our internal state of mind. For example, does age influence this 40% positively or negatively?
To find out, we asked each respondent a number of questions, ranging from overall happiness rating to employment status. How did these affect the ability to control our happiness?
The happiness rating of the respondents did not have a significant influence on the amount of happiness that is determined by their internal state of mind.
We asked the respondents the following question about their happiness:
If you look back at the last year of your life, how would you rate your happiness on a scale from 1 to 10?
We then grouped all respondents based on their answers. Finally, we averaged their percentage of happiness that is determined by our internal state of mind.
The results are shown in this graph:
This shows that no matter how happy our 1,155 respondents were, the 40% statistic was not influenced significantly.
There is no significant correlation between actual happiness and feeling like more of our happiness comes from within. In general, the happiest people in our group of respondents still felt that 40% of their happiness is determined by our internal state of mind.
The unhappiest people believed a smaller amount of their happiness is based on our internal state of mind (29%). However, the sample size of 15 respondents is too small to make any observations, especially since the standard deviation of the 40% statistic is relatively large at 14%.
Can happiness be controlled?
People who believe that happiness is something that is controllable are inclined to think that a bigger part of our happiness is determined by our internal state of mind.
We asked the respondents the following question about their happiness:
Is happiness something that you can control?
130 respondents answered “No”, while 1,025 respondents answered “Yes”. For each group, we averaged the percentage that they answered.
The results are shown in this graph:
People who don’t believe that happiness can be controlled think that 36.5% of their happiness is determined by their internal state of mind.
The other respondents believed that happiness can be controlled, and believe that 40.1% of their happiness is determined by their internal state of mind.
The difference of 3.6% is well within the standard deviation of all 1,155 answers, so it can be argued whether this is significant.
Commentary from the team:
Hugo Huyer, Founder of Tracking Happiness
This difference between 40,1% vs 36.5% is remarkably small. I expected there to be a positive correlation between thinking happiness comes from within and thinking that happiness can be controlled. In other words, those who think happiness can be controlled surely have found more ways to increase their internal happiness by training their state of mind.
But the 40% statistic seems to be universal, as in, all groups tend to think that roughly 40% of our happiness is a result of our internal state of mind.
This doesn’t say anything about how well we are able to influence this 40%.
In general, both women and men are inclined to think that 40% of our happiness is determined by our internal state of mind.
The difference between these two genders is merely 2% (41% versus 39%). This is well within the standard deviation of all 1,155 answers.
In general, the amount of our happiness that we think is dependent on our internal state of mind increases as we get older.
This is shown in the chart below:
The average percentages per age group are as follows:
- 16 – 30 years old: 38.5%
- 31 – 45 years old: 40.9%
- 45 – 60 years old: 42.2%
- 60+ years old: 45.2%
This data suggests that more of our happiness comes from within as we grow older. As with the other observations, the difference in percentages is relatively small compared to the standard deviation of the dataset.
The level of education of the respondents did not have a significant influence on the amount of happiness that is determined by their internal state of mind.
In another study article, we found that education is linked to the amount of control we feel over our happiness.
As can be seen from the chart, the amount of happiness we feel that comes from within is not significantly influenced by our level of education.
The marital status of our respondents did not have an influence on the happiness percentage that is determined by their internal state of mind.
Our employment status does not seem to influence the happiness percentage that is determined by their internal state of mind.
Even though students and unemployed people answered a higher percentage on average, the sample sizes are too small to mean anything significant.
Similar to our employment status and educational background, the amount of children of our respondents did not have a significant influence on the 40% statistic.
This study supports the 40% statistic
Our study supports the observation that was made in the 2005 paper ‘Pursuing Happiness: The Architecture of Sustainable Change‘.
The study suggests that 40% of our happiness is a result of our internal state of mind.
Some of the respondents’ characteristics seem to influence this number slightly, like their age and their belief that happiness can be controlled. However, the difference in the average percentage of these groups was always smaller than the standard deviation of all 1,155 answers.
This research gives us hope! If a massive 40% of your happiness is in your own control, then it becomes perfectly possible to learn strategies to become happier. It’s these ‘intentional strategies’ (strategies of thinking) that formed the basis of my own Ph.D.
Familiarity principle at play?
It can be argued that the answers from our study have been influenced by the popularity of the original 40% rule. This 40% was mentioned in the book “The How Of Happiness”, which has gained a significant amount of popularity.
Could the answers of our study be influenced by the familiarity principle?
We can safely conclude that is not the case. The book “The How Of Happiness” also states that a statistic that 50% of our happiness is determined by our genetics. Our survey asked how much of our happiness is determined by genetics as well, and the average of all answers was only 25%. This proves that the resulting 40% statistic of our study is not a result of the familiarity principle.
How was the 40% originally determined?
The 40% rule was determined in a paper which set out to find how much of the following factors influenced our happiness:
- Internal state of mind
There is a part of our happiness that is determined by our DNA. We can’t change this. Some people are simply more prone to be happy than others. This was studied by examining identical twins in 1996, where 44% to 52% of our well-being is associated with genetic variation.
In the 2005 paper, it was concluded that 50% of our happiness is determined by our genetics.
The difference between circumstances and our internal state of mind is that circumstances are things that happen to us. We can’t influence the things that happen around us, whereas we do have a certain amount of control over our own internal state of mind.
The 2005 paper states that 10% of our happiness is determined by circumstances. The 2005 paper refers to two separate papers from 1999, that state varying figures to account for circumstantial happiness ranging from 8% to 15%.
Upon investigation, the determination that 10% of our happiness is circumstantial is debatable. More details about this debate are included in this chapter.
Internal state of mind
With genetics and circumstances taking up respectively 50% and 10% of our happiness, that leaves as much as 40% of our happiness to our internal state of mind. Or in other words, we can influence 40% of our happiness with intentional actions.
These 3 factors combined form the 50-40-10 rule of happiness, which was made popular by the book ‘The How Of Happiness’.
Critiques of the 50-40-10 rule of happiness
The 50-40-10 rule has been critiqued recently in 2019, in a paper devoted to debunking the original 2005 paper. This is an interesting read for anyone who wants to get into detail on how the 2005 paper came to be.
It’s not just the determination of the 50-40-10 rule of happiness that has received criticism, though.
The fact that a large part of our happiness (~40%) is within our control has been critiqued as well.
The most notable criticism comes from the book “America the Anxious“. The premise of this book discusses how the constant pursuit of happiness actually results in anxiety within a society.
It provides the following critique of the 40% statistic:
This 40 per cent figure is much quoted in the positive-psychology literature in both academic and popular texts, and represents the field’s great marketing opportunity. This is the 40 per cent that anyone with a book to sell, a course of coaching to offer or a happiness technique to promote is hoping to co-opt.Ruth Whippman, author of “America the Anxious”
What initiated this 2020 study?
What initiated us – the team behind Tracking Happiness – to conduct this study was in part caused by this criticism. Criticism usually leads to progress, growth and improvements, provided that the people providing criticism actually make an effort to think in solutions and provide a better alternative.
It’s relatively easy to criticize, but we wanted to provide a meaningful addition to the existing models.
So even though a lot can be said about the method and validity of this study, it does offer an alternative point of view on the 50-40-10 rule that we believe is meaningful and interesting.
We’ve released study results on all three aspects of the 50-40-10 rule:
- 40% of your happiness is determined by your internal state of mind (as covered in this article).
- 36% of your happiness is circumstantial.
- 24% of your happiness is genetic (to be released soon).
If you’re looking for more information on how the study was performed, this article provides an overall introduction to this study. It also includes links to other result articles that are relevant to this study.
Want to know more details? Like who was surveyed, what are the demographics of the respondents, and how the study was performed? Here is a link to a document that explains it all (opens in a new window):
40% of our happiness is determined by our internal state of mind. This was first observed in a 2005 study, and has now been confirmed in a large-scale survey amongst 1,155 respondents.
This study suggests that happiness is something we can influence. If you learn how to implement positive changes to your internal mindset, you may end up with a better chance of living a happier life.
What do you think of these results? Let us know in the comments below!
Founder of Tracking Happiness and lives in the Netherlands. Ran 5 marathons, with one of them in under 4 hours (3:59:58 to be exact). Data junkie and happiness tracker for over 6 years.
Huijer, H., 2020. Study Confirms That 40% Of Happiness Is Determined By Our State Of Mind (A.K.A Within Our Control). [online] Tracking Happiness. Available at: https://www.trackinghappiness.com/study-confirms-40-percent-happiness-state-of-mind