As I learned from the answers to this question: In what adaptation of Return of the Jedi did Jabba brag about killing Jedi in the old days?, in the novelization of Return of the Jedi, Jabba the Hutt states that
I am not affected by your human thought patterns.
Seeing this reminded me of a debate I had with my father (roughly thirty years ago) about why Jabba was not affected by Luke's Jedi mind tricks. I, influenced by the Marvel comic adaptation and possibly the novelization, thought that there was something biological about a Hutt like Jabba that made him immune. (I did not specifically remember the lines from the novel/comic books, but their influence certainly stuck in my subconscious mind.)
My father, who had seen all three original films multiple times and had read at least one of the novelizations, thought that Jabba was unaffected merely because he was not the type to ever take orders; he thought for himself. This was presumably based on Obi-Wan's comment from Star Wars:
The Force can have a strong influence on the weak minded.
So what I am wondering now is whether there is any other information in the Expanded Universe about Hutt brains and why Jabba was so resistant to Luke's commands.