Anecdotally, there are several examples we can point to of an Avatar's personality being a reaction to, or otherwise influenced by, the life experiences of their immediate predecessor. For example,
- Roku's life as the Avatar was deeply pained by the conflict it created with his best friend, Fire Lord Sozin, a conflict which ended up directly causing Roku's death. Then, Roku was immediately followed by Aang, who had a deep, instinctive desire not to be the Avatar, a fear/desire so strong he actually ran away from home to escape it.
- Aang eventually overcame his fear of being the Avatar when he was forced to fight Phoenix King Ozai, at which time he became more willing to engage in direct confrontations (such as we see during his handling of Yakone) rather than evasion and misdirecton. Then, Aang was immediately followed by Korra, whose first instinct is always direct physical confrontation, as though she was instinctively preparing to be a wartime Avatar early in life.
One might even make a connection between Avatar Kyoshi’s head-on confrontational style (and the negative reactions we’ve seen it inspire in the Earth Kingdom), with her successor Roku’s more passive stance toward Sozin’s ambitions, which seem to have amounted to one fight in the palace followed by decades of avoidance.
Obviously some of this has to do with the elemental orientations of each Avatar, (airbenders are famously evasive, while waterbenders seem more forceful in general, etc), and the connections could easily be explained away as coincidence or narrative symmetry.
But given the emphasis on past lives in the Avatar narrative, is there any comment made (in the shows or the comics, or by the showrunners) about whether the experiences of one Avatar will influence the style/personality of the next?