Achieved though study, reading, learning, doing tests and reading some more and perhaps a few experiments here and there.
These skills are mostly based on knowledge rather than ability. And not everyone who possesses certain mental skills is automatically able to perform the actions corresponding with it. Like stated before, one can have a Ninjutsu skills ranked B, giving him Jounin-level (Elite) knowledge on the subject, but if they lack techniques within this range of skill or lack the Ninjutsu stat they might not be too good at performing at it. They just know a good deal about it. If untrained however the person receives a -3 penalty to all actions attempted corresponding with the given skill.
AcademicsGeneral Academic Knowledge
PoliticsGeneral Political Knowledge
(Academics D required)
ScienceGeneral Scientific Knowledge
(Academics B required)
MedicineGeneral Medical Knowledge
(Academics C required)
Chakra ControlThe ability to mold and manipulate Chakra
CraftThe ability to craft/repair non-metal objects
TechnologyGeneral Knowledge of Electrotechnology
(Academics D required)
Iryō NinjutsuMedical Ninjutsu Techniques
(Medicine C required)
Nin JutsuYin-Jang Release Basic Ninjutsu Techniques
(Chakra Control D required)
Katon JutsuFire Style Techniques
(Ninjutsu D required)
Raiton JutsuLightning Style Techniques
(Ninjutsu D required)
Fuuton JutsuWind Style Techniques
(Ninjutsu D required)
Suiton JutsuWater Style Techniques
(Ninjutsu D required)
Doton JutsuEarth Style Techniques
(Ninjutsu D required)
InvestigationInvestigation skills
(Academics D required)
Fuuin JutsuSealing techniques
(Academics B required)
(Sealing Knowledge 6 Required)
GeneticsGeneral knowledge of Genetics
(Academics B, Medicine C, Science C required)
ChemistryGeneral knowledge of Chemistry
(Academics C, Medicine C required)
Kekai NinjutsuBarrier Ninjutsu
(Academics C required)
Jikūkan NinjutsuTime-Space Ninjutsu
(Intelligence 5, Sealing Knowledge 5, Chakra Control C
Academics D required)
BlacksmithThe ability to craft/repair metal objects
(Academics D required)
DeductionConnecting little pieces of information into one.
(Academics B, Investigation C, Intelligence 9 required)
Subject: Mental Skills 
Wed 17 Apr - 4:35
