It will depend if the vehicle has a limited slip diff or a diff lock.
LSD's will transfer drive from the slipping wheel to a wheel that has traction, so, if one wheel is in the air, the drive will be transferred to the wheel on the ground.
4WDs with a locker in them will spin the wheels at the same rate. It does what it says, locks the wheels. Both wheels will get the same amount of drive at all times.
Some toyotas have a automatically operated locker which kicks in when 4WD is selected, or some have an aftermarket kit where you have to lock a switch.