These are separate from skills, but they share some similarities. A single IP in a stat results in an 0.01 increase. Valid stats work together with raw skills to provide your total in that skill.
“Your ability to shrug off negative status effects, such as cold, muscle strain, heart attacks...Endurance
“This stat determines how well and how clearly you can think. Very useful for skills such as...Brains
“Sheer strength, your ability to carry heavy loads and use heavy weapons. Affects weapon damage...Brawn
“Cool is how hip you are, how collected you are. How well you can control your body. Also it's...Cool
“Represents your speed of movement and how accurately you can control your functions. It also...Reflexes