viewof benefit_of_kindness = cell(
`
/* How much happier is someone right after someone did something kind for them?
The estimate is based on the study by Pressman et al. (2015) and Zhao and Epley (2021).
*/
//According to the increase in Duchenne smiles observed by Pressman, Kraft, and Cross (2015). The effect size reported in that study was //1.1. I estimate the width of the confidence interval on that effect size to be about 0.3.
effect_of_kindness_on_smiles = normal_from_ci(1.1-1.96*0.3,1.1+1.96*0.3) // normal distribution with 95% CI [0.5,1.7]
// Effect of compliments according to Experiments 1 and 2 by Zhao & Epley (2021) being complemented boosted the recipients' mood by 0.66 // standard deviations
effect_of_compliment_on_mood = normal(0.66,0.20)
// To express the assumption that each empirically documented effect-sizes is equally likely to occur when someone benefits from prosocial behavior, we create a mixture distribution.
peak_amplitude_of_joy_beneficiary = mx(effect_of_kindness_on_smiles, effect_of_compliment_on_mood)
//How much happier does a person feel right after being kind to someone else?
peak_amplitude_of_joy_benefactor = normal_from_ci(0.16,0.41) //95% Gaussian posterior credible interval: [0.16,0.41] according to Curry et al. (2018)
//Average duration of joy according to Verduyn, van Mechelen, & Tuerlinckx (2011)
avg_duration_joy_h = lognormal_from_mean_and_std(1.7267,0.1086)
//I calculated the total joy per unit event by calculating the area under the joy intensity profile shown in Figure 6 of Verduyn, P., Van Mechelen, I., Tuerlinckx, F., Meers, K., & Van Coillie, H. (2009) using numerical integration with the trapezoid rule in Matlab (trapz). Because a unit event lasts one unit of time, the result is also the average level of joy during a unit event.
avg_intensity_of_joy = normal(0.4796,0.1) // The mean value is the area under the curve in Figure 6. The standard deviation estimates the effect of the unreported uncertainty. Given that this number corresponds to the average across 260 graphs, I believe this estimate to be high enough.
hours_of_happiness_per_SD_joy = avg_duration_joy_h * avg_intensity_of_joy
//Sum up the beneficiary's increase in affective well-being over time in hours of happiness.
//Arguably, the beneficiary's emotional response might be closer to gratitude than joy. However, according to Verduyn & Lavrijsen (2015), the durations of joy and gratitude are similar.
total_effect_of_one_act_of_kindness_on_beneficiary = peak_amplitude_of_joy_beneficiary * hours_of_happiness_per_SD_joy
//Sum up the benefactor's increase in affective well-being over time in hours of happiness.
total_effect_of_one_act_of_kindness_on_benefactor = peak_amplitude_of_joy_benefactor * hours_of_happiness_per_SD_joy
//the total benefit is the sum of the benefits to the benefactor and the beneficiary
total_effect_of_one_act_of_kindness_on_beneficiary + total_effect_of_one_act_of_kindness_on_benefactor
`, cea_functions, {distributionChartSettings: {showSummary: true, title:"Hours of Happiness created by one act of kindness.", tickFormat:","}}
)