Jeff or Kyle can correct me if I am wrong, but it is usual practice to cut hardwood 1/8" oversized- 4/4 would actually be cut 1 1/8" thick. It will shrink to 4/4 or less during drying.
However, that being said, I have still found that with anything other than the best stock with no twist and no internal stress, it is still better to cut it to 5/4 (actually 1 3/8 if you want a final thickness of 3/4. That gives you some allowance if you need to do a lot of jointing to remove warp, cup, or other surface irregularities.
Some cabinet makers use 13/16" dressed stock for faceframes and door stiles/rails. Once the glue has dried they run the door through a drum/belt sander to level any misalignment between stile and rail joints, to end up with 3/4" thick doors. Starting with 4/4 thick stock will give only 3/16" or less allowance to remove warp, cup, etc. on the jointer if you are going to plane it to 13/16.