Well the parent made sort of a case for why being reasonable is part of being intelligent, and your response was to claim there was no correlation without an argument.

I happen to believe that reasonableness is part of being intelligent, by the following criteria:

1. when you are reasonable you do not make unreasonable demands that will just be troublesome and cause workflow issues because in the end they are unachievable.

2. a reasonable person will be able to determine what other people are capable of in given situations, and be able to structure things in such a way that other people can perform to best meet expectations.

3. the root of reasonable is reason, a reasonable person can be reasoned with because they possess the quality of reason, in most of the history of philosophy if you do not possess the ability to reason you are an idiot.

Having worked closely with some dramatically different intelligent people, I really think intelligence and reasonableness are very different.

Being reasonable, is being someone with a strong genuine value for collaboration. They actively advocate for and work with others to optimize situations taking everyone's needs into account. Encourage give and take, constructive debates, and appreciate feedback. Etc.

An intelligent person can be all those things. Or none of them - but manifest them enough that, with some spin, they seem reasonable, while actually optimizing the environment primarily for their own long term benefit.

Very intelligent unreasonable people are disasters to work with.

Alright, my argument is that parent needed to redefine what those words mean. Intelligent means having high intelligences, high IQ. That does not imply being reasonable or having emotional control. It does not imply ability to shut up when you do not know what you are talking about either.

Moreover, being able to admit mistakes (specific thing mentioned by parent) is oftentimes detrimental for you. People who do not admit them are typically rewarded, people who easily admit them punished. So, what you are looking at is "ethics even if it does not benefits me".