The book involved a group that had crashed onto a planet that augmented their natural abilities. A group of characters (the bad guys) became talented liars and politicians. A geologist (the good guy) could communicate with the sentient planet. Eventually, he talked the planet into swallowing the bad guys.
This sounds like Orson Scott Card's novel A Planet Called Treason (1979), later rewritten as Treason (1988).
In this book, different families have different territories and different talents, based on the occupations of their founders:
Schwartz, lost to all human contact on the desert―she had been a geologist. Wasted on this world without hard metals. ...
Anderson―the useless leader of the rebellion, whose only gift was politics.
The protagonist, Lanik Mueller, can regenerate his body parts; the Schwartzes can communicate with and control rocks and earth; and the Andersons can create illusions. Collaborating with the Schwartzes, Lanik eventually manipulates the planet so that Anderson Island sinks into the ocean.