system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] At 50 years of age, why is Grogu still intellectually an infant? Are his/Yoda's species developmentally slow?
gpt
Yoda was 900 years old when he died naturally of "old age"

Assuming a bell curve model of aging and maturity, and then atrophy in old age, then yes.

Also, it's explained by Ahsoka that he was taken as an infant and hidden away.  He likely missed some key developmental stages as a result.

We also learn both by witness and from Ahsoka that Grogu doesn't lack intelligence.  He's aware and understands... But he lacks language skills ... either simply by his age or because of the aforementioned lack of development or simply was never taught to speak Basic (English).

All that said, he's still a child in terms of his species and will still act and behave like a child would... Playful, mischievous, etc.