🚨 WIDER GRIP = WIDER LATS? NOT REALLY!
✅ I’m pretty sure you’ve heard this countless times: “grip the bar at its widest to develop a wide back.”
✅ And mind you, I actually believed the same for a while, until I questioned this very thing myself on how would that actually even work.
✅ Muscles grow as a response to a continuous & progressive stimulus induced by training, fueled by proper nutrition.
As long as the stimulus is meaning that it is actually hitting the muscles you’re looking to develop by fully contracting them, they will grow. And by “growth” you get both: thickness & width.
Although the studies I’m presenting took the Lat Pulldown to show the results, the same applies for pull ups too since both exercises activate lats similarly. 
A medium grip seems to works even better than a wider one, research shows. 
And this because a narrower grip allows for better technique & ROM (range of motion), which seems to have a greater impact on not only lats, but also trap & infraspinatus muscles as well.
🚨 How wide, you ask?
✅ It’s gotta feel comfortable and you gotta be able to perform full ROM in order to fully contract your back muscles, and maintain your shoulders in a safe spot: my suggestion is around 1.5 shoulder width.
❌ A wide grip for them ego lofters: “yuh braw, you need to grip it at the opposing edges of the bar to stimulate that width brah, yeuh!!.”
✅ By gripping the bar so wide, you will never be able to even fully complete the movement. Your shoulders won’t even be able to stay locked down and back (which is how you should perform the exercise), so they’ll be more likely to internally rotate and completely shut down lat engagement. As a result you’ll get a bro-spotter to help you out with your struggling reps, some shoulder pain, and probably zero back development.