Admittedly Anglo culture took a lot of influence from the scandinavians (due to Viking conquest etc). I think some of the cultural tenants we are talking about probably did come originally from Scandinavia.

Isn't the suicide rate highest in Scandinavian countries and lowest in South Europe?

The more sad people kill themselves, the happier is the average survivor?

In a static population sure. Over decades?

Britanica did a video on this: https://youtu.be/ldvQOnvc2Io?si=9R1IHMfS0i7RhB8s

Different cultures also define happiness differently. For the scandanvians, happiness stems from contentment and balance, American society tends to link it to consumerism and material success.