An Equation for Happiness?

It’s no secret that the level of personal happiness isn’t directly linked to the material things in life. This is well illustrated by the fact that this year, the crown of the happiest nation in the world went to Panama, according to the Gallup and Healthways Global report. In comparison, the UK is ranked 76th on the list. So what really makes people happy?

It’s hard to describe happiness, let alone to measure it. We all see it differently. Psychologists have multiple theories in this regard. Neuroscientists point to multiple brain mechanisms and the levels of different neuromediators. Clinicians have studied multiple environmental and medical factors leading to various mood disorders.

The picture is complex, and putting various influencing parameters into one equation that could have a predictive value would seem to be an impossible task. But this is exactly what researchers from University College London have attempted. In their article published in the prestigious Proceedings of the National Academy of Science they’ve suggested an equation that rather accurately calculates the level of moment-to-moment happiness.

The equation takes into account two major factors: expectation and reward. In their experiments, the researchers asked 26 volunteers to participate in decision-making tasks that could lead to some real monetary gains or losses. Brain activity of participants was monitored using MRI during the course of the experiment. At regular points during the tasks, the researchers asked participants to evaluate their current level of happiness with how they felt things were going.

It turned out that happiness wasn’t linked to the amount of wealth accumulated. Rather, happiness was experienced when things were going better than expected. On top of this, recent rewards substantially influenced the moment-to-moment happiness.

The data obtained in this experiment allowed researchers to develop an equation for predicting the relative level of happiness. The idea was put to the test in a further experiment involving much larger group of people (above 18,000), using a specially designed smartphone game called “What makes me happy?”.

The participants faced the same kind of decision-making tasks, but this time they were receiving only points, not real money. Nonetheless, the outcome was the same, and the previously developed equation accurately predicted the happiness level of participants.

The scientists consider the game as a model of real-life situations in which we should make important decisions, for instance when we start new job or project, get married, or make serious changes to our personal life. The outcome of such decisions is often far from clear, but we do expect the changes to be rewarding, at least to a certain extent. The perfect match between actual outcome and previous expectations makes us satisfied. When outcome is even greater, we feel happy.

The actual size of the reward is secondary. For instance, a person could feel quite happy after winning $100 in the lottery, since the chances of such a win are very slim and the objective expectation of winning anything at all is very low. On the other hand, an investor who expected to get $1 million from trading his shares, but received only half of this money is likely to be unhappy, even though the actual amount of money he received is very substantial.

What determines happiness on the molecular level remains rather uncertain.

MRI studies show that the neural signals in the part of the brain called the striatum can help in predicting moment-to-moment happiness. The striatum coordinates motivation with body movement. It’s involved in complex social interactions and may inhibit certain types of behavior. It’s also involved in executive functions such as working memory.

The striatum was shown to be activated by the stimuli associated with rewards. In the classic experiment performed back in the 1950s, it was shown that neuron-stimulating implants placed in the striatums of rats made the animals press the bar sending the stimulus to the brain for hours at a time.

Recent data suggest that the reward process is linked with dopamine neurotransmission. The striatum has lots of connections with dopaminergic neurons, and thus it appears that the changes in the level of dopamine in certain regions of the brain may be involved in determining the degree of happiness. Future research into the function of striatum may help us to reveal in more details the molecular determinants of happy feelings.

In the meantime, the equation developed by British researchers might be of practical importance for clinical purposes, particularly for treating patients with mood disorders. It also points out yet again the importance of managing expectations, both on a personal level and in wider society.

Obviously, the equation doesn’t calculate the level of overall personal happiness with life, the Universe, and everything. But let’s keep in mind that overall happiness is eventually the sum of your everyday experiences.


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Volman, S., Lammel, S., Margolis, E., Kim, Y., Richard, J., Roitman, M., & Lobo, M. (2013). New Insights into the Specificity and Plasticity of Reward and Aversion Encoding in the Mesolimbic System Journal of Neuroscience, 33 (45), 17569-17576 DOI: 10.1523/JNEUROSCI.3250-13.2013

Rutledge, R., Skandali, N., Dayan, P., & Dolan, R. (2014). A computational and neural model of momentary subjective well-being Proceedings of the National Academy of Sciences, 111 (33), 12252-12257 DOI: 10.1073/pnas.1407535111

Image via FWStudio / Shutterstock.

Viatcheslav Wlassoff, PhD

Viatcheslav Wlassoff, PhD, is a scientific and medical consultant with experience in pharmaceutical and genetic research. He has an extensive publication history on various topics related to medical sciences. He worked at several leading academic institutions around the globe (Cambridge University (UK), University of New South Wales (Australia), National Institute of Genetics (Japan). Dr. Wlassoff runs consulting service specialized on preparation of scientific publications, medical and scientific writing and editing (Scientific Biomedical Consulting Services).
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