There's plenty of research counter to that, showing that regardless of negative or positive events happening in one's life, people tend back towards the same happiness they were at after a few years.

I wouldn't say it "counters" it, rather it very much depends on the events and/or circumstances. Winning the lottery won't make you happy. Losing your job and failing to get another one will probably make you sad. Traumatic events can be very hard to get over.

Funny enough the only example I've found of an "event" having a long term positive effect is cosmetic surgery

> long term positive effect is cosmetic surgery

Any links? It isn't clear whether you are talking about cosmetic surgery to mitigate an obvious issue (for example, correcting a hair lip or removing a disfiguring facial birthmark), as compared to cosmetic beauty enhancements (nose job or tummy tuck). I would guess "enhancements" have a very strong sampling bias, because of a strong correlations with disposable income, belonging to certain social groups, and the type of person that prioritises surgery over other expenses. Adjusting to remove bias would be problematic?

I also suspect that there would be an inherent bias in reported studies, because the cosmetic surgery industry will fund and publish results that benefit the industry?

"Other researchers have investigated the effects of life events which can cause medium term and perhaps permanent change in set points. These events include the unexpected death of a child (Wortman & Silver, 1987), repeated spells of unemployment which have a ‘scarring effect’ (Clark et al, 2004), becoming widowed and perhaps getting married (Lucas et al, 2003). Amusingly, the only favourable or positive ‘event’ unambiguously shown to enhance long term subjective well being seems to be cosmetic surgery (Wengle, 1986; Loewenstein & Frederick, 1999)"

Copy-pasted from a 2006 paper by Bruce Headey I had lying around. I haven't looked into this in a few years but you might be able chase those refs down if you're interested

I think it's astounding that people take happiness-set-point theory so literally. Has everyone here been uniformly happy/miserable throughout their life? I certainly haven't - when things have been bad I've been miserable, when things have been good I've been happy

If a person does not revise their core beliefs based on acute events, then, given time, their chronic happiness level will revert to what it was (speaking very generally).

I don't agree with the implication that genetics are to blame, but rather I believe it is incredibly difficult for a person to change their core beliefs, even when reality is at odds with those beliefs.