Why is peanut butter viscous? Why is it that when you chop peanuts, a highly viscous paste is created?

Im assuming that the reason that chopped peanuts dont become just dust is because we cannot chop finely enough, but what causes the chopped particles to adhere to each other?
Peanuts contain peanut oil. When you crush the peanut you also compress some of the peanut oil out out of the nut particles.