120 is still quite high though, there is probably a certain amount that together with luck/support/success indicates you would do well in your chosen field. (If this field allowed you to utilise your intellectual strengths).
I would find it hard to tell my parent’s IQs. Firstly I haven’t spent enough time with my dad. They both left school around aged 15/16 maybe younger. I suspect my dad has a decent IQ (sorry for the cringe word, I don’t want to do numbers) but you wouldn’t know unless you had many in-depth convos with him, which I haven’t. (Still my dad and I have a hunch). The lack of education and worldliness probably makes them seem like they have lower iqs. But my dad seems like he really likes his job- think he earns quite well and the work involves electronics, but he probably considers himself a tradesman of sorts. I think his iq is higher than my mum’s but he has a significant socionics subtype and my mum is more balanced and independent.