iPhone 6s Tricks: Mastering 3D Touch
Adjust 3D Touch Sensitivity or Disable It Altogether If you want to change the responsiveness of 3D Touch or turn it off completely, go to Settings > General > Accessibility > 3D Touch. Here you can disable 3D Touch or adjust the sensitivity levels to Light, Medium, or Firm. Light reduces the amount of pressure needed to make 3D Touch work. Firm increases it. Make sure you've got the setting right by using the sensitivity test provided.