Are they actually 25YO mentally?

finally.. someone spell it out... yk what...because of them, at some point, I was wondering am I the stupid one because they can't even realize after all the hint that were given out ... I'm so done that I almost drop this... stg their mental age is frickin older than me!? how !?

They were wary of everybody except the true bad guys

ikr! even after the maid that they put their trust on tell em not to trust the Duke... they still do it lmao...

The second prince even told them straight up that being royal was dangerous. They aren't kids mentally to be so naive. Be wary of everybody at the very least(╯°Д °)╯╧╧

and yaknow what other people are sayin?
"in their past live, they died at their teens age and reincarnate so they technically doesn't reach adulthood yet so ye"
and I'm like... I'm pretty sure, even primary school kids these days are better than that and also they're not that naive at least in my country

I am copy pasting my previous comment and read with caution especially for younger audience, some information are quite disturbing.

They were 18 years old before reincarnated. At that age, your brain is still developing, which is why teens phase are often called the rebellious phase. Quite literally your brain is still changing (you can google this, when is your brain stop developing and different mental moral development stages). Now imagine, if you are still living your teenage years, and you die, then reincarnated to an abusive mothers, and unkind environments (not getting proper food, water, exercise, education, etc) for 7 years. Your brain are still not developed at the time, so forget your mental age, you are essentially regressed to being a child. An extreme example of this is Genie https://en.wikipedia.org/wiki/Genie_(feral_child).
I have watched a documentary of 50+ years old men, were sexually abused when he was a boy up until 14 years old, could not cope with it emotionally even after 50 years old (source: watch “tell me who I am” or read this https://www.latimes.com/entertainment-arts/movies/story/2019-10-21/tell-me-who-i-am-netflix-documentary-child-abuse ).

Let us say for sure their mental age before dying is 17, but we still have no further information from the twins previous family. Gene is one factor that could affect your IQ - your mothers nutrition when they were pregnant. The second factor is nurture or the environment the twins live in. Experiments were conducted before in the 70’s to find out how can nurture or nature affect child development, which ‘three identical strangers’ documentary look into this https://www.latimes.com/entertainment/movies/la-et-mn-three-identical-strangers-documentary-20180702-story.html . The experiments were still not published because it is not ethical in today’s world, but basically I can get the give you the gist info from the documentary. 3 babies (triplets) were born and situated to different household. One the dad was busy but loved the boy, second dad loved the boy and the dad’s world revolve around his boy, the third dad is very hard and harsh with the boy with very traditional teaching. Later one of the boy from the triplets commits suicide, and you can guess which boy it was.

Human mind and behaviour is not easy to deduce, you can be rational with your judgment in your respective individual settings, but even that individual settings are depend on your family gene and more largely depend on your environment when you grew up. I’m sorry for the information dump and thank you for reading this up until now, I hope this information is helpful.

If you are interested in adolescent brain development, I found a paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3621648/ that can explain more on this.

Thanks for the materials.

Now, genuinely curious, do you think the inconsistency of their wariness stem from being transformed as infants and the trauma too?

We can see that the twins are wary bec of what happened and what their father's inaction did.

And although they actually trusted the nanny bec she dished out cold hard truths as opposed to other people and the other kid due to being in the same scenario as them. As opposed to the little interactions with the Duke they seem to not be wary of him?

Or this is just another convenient plothole?

This, I don't think their personality is need a deep explanation it just a bad writing imo

Agreed, it is just bad writing at this point. I find it hard to believe that their judgement of character is this bad and yet still claim they’re matured mentally.

With all due respect, the examples you give all has the assumption that the abused children knows of no better conditions. We don’t know what their past lives are like. Sure. But if they’re so distrustful of everyone, they should be just as distrustful of the antagonists. I won’t go into the dualities of nature vs nurture, or the implications of a blank slate, but even in their infant hood as newly reincarnated children, they should not even be able to compute worldly information with an infant brain, if you truly wish to apply child psychology into this. All that is to say that their circumstances unique, but even the author doesn’t go into mental capabilities, besides the trope that to other characters, they appear more mentally mature than their ages. I don’t deny the implications of a rough childhood; better examples imo would be children rotated constantly through foster care. But the twins’ shoddy character judgement is a glaring plot hole that delegitimizes whatever trauma trope the author uses to perpetuate misunderstandings that could easily be resolved with proper communication.

I am giving you examples of what could happen, before and now. Does not mean that my info can really be what happen, its just one way to look at it, because fundamentally you are asking are they really 25 year old mentally? I heard that the novel, the twins doesnt act like this, they don’t even talk to people initially at all, the manhwa brought changes to the conversations and characters, which is why as you suggest plothole happens,