Each tribesperson has seven skills that they can earn experience in for completing tasks in each of those respective areas. The seven skills are fishing, wood gathering, rock gathering, construction, agricultre, science, and art. Out of the seven skills, only agriculture experience can be earned from multiple activities; farming, planting flowers, and growing trees. As tribespeople become more experienced in the different skills, they start working faster in each of those areas. Some island mysteries must be solved by having a tribesperon with maximum experience; the rock gathering, agriculture, and science skills.
The skills list on a tribesperson's details page. This tribesperson has maximum experience in all seven areas