Rutledge and his team also compared the model to a number of alternative models and found that it had better explanatory power, with a goodness of fit of 0.47.

They conducted a series of behavioral experiments to verify the validity and robustness of the mathematical calculation formula. Because people may not be good at estimating current earnings, the team designed a computer screen to display participants' current earnings.

The relationship between actual earnings and happiness was stronger, but still not significant. They also designed the subjects' gains to be shown only in certain randomly selected rounds, again with robust results.

Since the expected return has a positive and significant effect on the happiness index when the subjects choose the risk option, while the actual return has no significant effect on the happiness index,

and the RPE value is equal to the actual return minus the expected return, it is very necessary to conduct a more rigorous test on the RPE value. If the RPE value is positively correlated with the happiness index,

then the actual return split from the RPE value should be positively correlated with the happiness index, while the expected return split should be negatively correlated with the happiness index.

And the greater the negative impact of the expected return split, the greater the positive impact of the actual return split, so that the RPE value can have a positive impact on the happiness index. The experimental results further prove the author's hypothesis that the weight coefficients of the two are indeed negatively correlated.

In addition, the research team also conducted large-scale experiments on smartphone platforms such as Apple's iOS and Android mobile phone systems. As many as 18,420 anonymous trial phones participated in the experiment, and the results further verified the universality and robustness of the model.

Instantaneous happiness is related to expectation error

We all know that dopamine is a neurotransmitter associated with happiness, and the more dopamine the brain produces, the happier people feel. Neuroimaging studies have shown that RPE values are closely related to the ventral striatum,

which is the neural target of dopamine action. We have to admire Rutledge and his team's exceptionally rigorous scientific spirit, they conducted a functional magnetic resonance imaging (fMRI) experiment to further verify the results of their behavioral experiment,

and found that the level of striatal activation during the experimental task was significantly correlated with the happiness of the participants in the subsequent round. The authors verified that the activation of the ventral striatum could also be explained by the above mathematical calculation model,

and the CR, EV and RPE values were significantly positively correlated with the activation of the ventral striatum. Activation of the ventral striatum was not significantly associated with transient happiness.

They also found a positive correlation between activation of the right anterior insula and instantaneous happiness. This is consistent with previous research, as the right anterior insula is thought to support people's interoceptive emotional perception.

Rutledge and his team also found that participants who reported higher levels of happiness had more volume of gray matter in the right anterior insula. To see if there was a connection, they asked participants before the experiment,

"How satisfied are you overall with the state of your life these days?" To measure their permanent happiness, and then to see if permanent happiness is also related to activation of the insula, and there was no such correlation. This means that different forms of happiness have different neurological and psychological mechanisms.

Behavioral and brain science experiments by Rutledge and his team have shown that people's instantaneous happiness is not directly related to the outcome achieved, but rather depends on the difference between the outcome and the expectation,

which is consistent with Samuelson's speculation. The authors used regression to estimate a forgetting factor of 0.61, meaning that decisions made 10 rounds earlier had almost zero impact on momentary well-being at the moment.

At the same time, the experiment also showed that happiness was positively correlated with people's temporary expectation error, which led to the release of dopamine in the brain, indicating that dopamine plays an important role in regulating people's emotional activities.Some thoughts on popular science

In the process of practice and research, terms such as popular science and science communication are often used alternately by different researchers. At the beginning of this century, there was also a debate on whether science communication should replace popular science.

The two sides of the debate had their own words, and in the end, neither side of popular science and science communication was replaced by the other side. Because "the difference is not historical or hierarchical,

but just focuses on the difference... It is essentially a democratized practice of science, but the content has changed ", but "science communication and other terms used in the field of science literacy are vexed by their lack of clear meaning".