Question

I recently happened to read a few articles that were sent to me claiming that happiness is 50% genetic.
I’m always pretty skeptical about studies like these, but it got me thinking: maybe it’s true—and if it is, how is it even possible to test something like that?
Is this an empirical field? Or is it more psychological?
I assume that at the root of the question is my discomfort when faced with headlines like “A new study determines,” which on the one hand creates an aura of “truth,” and on the other hand automatically arouses skepticism.