Oh, an agnostic.
There is something to be said about groups of people that hold similar ideas because their similar way of thinking lead them to similar conclusions. It's a very important exception to the OP's description, where the group came first, and may even be the most common kind.
(Of course, the question to answer is why do those people think in similar ways.)
> part of the group of software engineers by trade
I'd bet that one lead you into adopting some values.
You probably also have some abhorrence towards formal chaos (the ones that causes unpredictability; many are not even able to accept it exists) and want to improve every system (simple or not) you see.
On the more traditionally politics kinds of thing, you probably value freedom of expression to a very high amount, like other highly educated groups, but also probably value personal freedom and personal initiative. Those often come in an intensity that leads to some bullshit levels of belief in self-determination (like in not believing you share group values) and personal responsibility; but beliefs change faster than values, and many people tame those down with time.
Invariably, in every discussion, they'll trot out this sentence: "You <opponent group name> people always think <notion>".
For example: "You Liberal party voters always support lowering taxes" or somesuch sentence.
I point out that I didn't vote for the Liberal party.
"The Labour party voters are the same!"
I point out I didn't vote for Labour either in the most recent election either.
"Err..."
-- at this point their brain locks up, because they're expecting a tribe-vs-tribe fight and they have no idea what to do when they discover I don't actually belong to their "enemy tribe".
Even saying you’re !group makes you explicitly a member of the !group group!
I've come to realize that "white male software engineer" is one of the groups with the highest ratio of priviledge versus priviledge awareness.
(Disclosure: I belong to that group as well.)
> I don't feel like I'm a member of many groups.
And this part:
> I suppose you could say I'm part of the group of Caucasian males by birth or part of the group of software engineers by trade,
So, you are belonging to three priviledged groups. Male, Caucasian, software engineer. It's easy to overlook this group membership, since it silently represents priviledge. Those outside these groups definitely notice that they are not in them. Ask a discriminated woman, a discriminated non-white, or an amazon warehouse worker.
That's why I pointed out that it's easy to forget group membership that confers priviledge.
> Also you're assuming a lot about my background
No, I went by exactly the information you conveyed yourself. See above.
> The power of reasons is an illusion. The belief will not change when the reasons are defeated.
So privilege plays an interesting role. Unaware privilege - failing to see ones own circumstances, failing to assess how we fit in the world - is almost the same thing as non-reason. I suppose there could be a class of people who are like, "I am totally privileged, and somehow I delude myself and don't notice, but in every OTHER way I am totally reasonable." That could be a subgroup. But probably not a big one?
If you prioritize truth over group membership, you are more likely to see your own flaws, the flaws in others, and prevent yourself from making catastrophic errors in your inevitable ignorance.
If you prioritize group membership over truth, you are more likely to fall prey to lies that have only short term benefits for one or more members of the group and eventually lead to catastrophic errors.
The best groups are the groups of people who are legitimately pursuing the truth, even if they are temporarily ignorant, which again, is inevitable due to information constraints.
We've become so saturated with power dynamical thinking we've forgotten that it is possible to be motivated to try to see the world accurately so as to best cooperate with it regardless of power differentials.
Not everyone is brainwashed to accept group think no matter in what cirles they have to evolve in.
There are individuals and then there are the parrots who mindlessly repeat what the group says.
You might be a "rational, fully self-realized, and atomized" individual but your behaviors and thoughts are certainly influenced by those around you. Here's a simple example: https://dictionary.apa.org/social-facilitation
Who isn't a member of a group? We're all members of a number of groups.
It's refreshing that Kahneman honestly admits that he doesn't change his mind either, and his tastes were formed when he was relatively young. He's not putting himself above the rest of humanity. He could easily say, "Well I'm a famous and distinguished scientist, so obviously my beliefs are rational, unlike everyone else", but he doesn't.