Allow me to make some observations.
- Neither the study nor the article tells us much about the "science" of happiness. It merely reports statistics about people's reported happiness and expected happiness.
- To a large degree, the article correlates happiness with material wealth.
- Efforts to study happiness scientifically seem to reduce happiness to a formula, typically including material wealth, physical health, convenience, education, and relationships.
Ironically, if we pursue happiness, we may not find it. Being self-centered rarely makes one happy. So, as we put others first, and choose a good attitude, we experience happiness as a byproduct. I don't think you can put that into a formula.