What do you think Franz would've turned out to be like if things had went differently and he had remained in France and was raised by Napoleon? He seemed to be a kind hearted young man but somehow I think if he grew up in France, he probably would've been more of a spoiled child considering how Napoleon treated him in his early childhood, and would've probably grown up to be more arrogant.
This is a difficult question because it all comes down to the nature vs nurture debate, which is something I haven’t fully formed my opinion on, but I’ll do my best to answer coherently!
He was a very fussy and bossy toddler, however it’s hard to tell how much of that was just normal toddler temperament and how much it was the effect of being spoilt. When he was three years old and he first arrived in Austria, his 12-year-old uncle Franz Karl refused to play with him because he didn’t want to play with a French boy, and although little Franz didn’t understand enough German to know what Franz Karl had said, he knew it was an insult and cried out “mother, I want that rascal taken away!” - some people may interpret this incident as a spoilt child trying to abuse his royal authority, while others may interpret it as a normal toddler tantrum. He also frequently threatened to have his nannies locked up in prison. The sources on his behaviour as a young child really differ depending on who wrote them - an Austrian police report from when he first arrived in Austria calls him “impetuous, willful, despotic”, but again you could just say that’s an exaggerated description of normal fussy toddler behaviour.
Meanwhile the letters of his French nannies show him to be a kind and caring little boy: when Madame de Montesquiou was sent away, Madame Soufflot sent the following letter to her describing the young prince’s reaction to the sad news:
“I cannot express the sorrow the prince felt this morning when, according to your intentions, Chan-chan told him of his misfortune and ours. We could only calm his tears and deep sighs, which came
from the depths of his heart, by assuring him that he would see you again. He wanted to write to you himself…”
And he had written at the bottom of the letter, with Madame Soufflot’s assistance since he had only just turned four:
“I love my dear Maman Montesquiou with all my heart.”
So the records of his early childhood provide quite a complex image where he was both very bossy and very kind, and it’s unclear how much of that was just typical behaviour for a young child or whether he had been spoilt from his immensely privileged upbringing.
There are certainly some areas where being raised by his father in France could have led to personality flaws - throughout his life he oscillated between having a superiority complex, believing that the reason why nobody understood him was because he was so much more intelligent than them, and having an inferiority complex, believing that he did not deserve to be his fathers son, and had he been raised in France the sense of superiority would have been much stronger. He was also extremely stubborn and didn’t like being told what to do, and this would have been much worse if he’d been raised in France.
But on the other hand, there were several personality flaws that he developed in Austria as a result of childhood trauma. For example, after being told lies about both of his parents throughout his childhood, he found it very difficult to trust people and rarely confided in anyone. He could also be very judgmental. I think that if he had been raised in France he would have had a more positive opinion of humanity in general and would have been happier.