Practice doing the Spock "live long and prosper" sign (🖖), putting all four fingers back together (✋), and then stretching only your pinky and index finger out to the sides (with your ring and middle fingers still together in the middle; sorry, no emoji for that one), then put them all back together again (✋), and repeat. You'll eventually get it, but stretching those tendons out early on takes some work.
Source: some 1990s issue of Guitar World where Kirk Hammet was going on about warm-up exercises. He learned this one from a physical therapist after he broke his wrist while skateboarding back when he was a teenager.
Wtf I just realized I can only move my right pinky independently, on my left hand my ring finger goes too
I assume you're left handed then?
Nope
Huh. My fret hand is the one that got +1 dexterity. My only other guess is that you did way more finger picking than I ever tried.
Practice doing the Spock "live long and prosper" sign (🖖), putting all four fingers back together (✋), and then stretching only your pinky and index finger out to the sides (with your ring and middle fingers still together in the middle; sorry, no emoji for that one), then put them all back together again (✋), and repeat. You'll eventually get it, but stretching those tendons out early on takes some work.
Source: some 1990s issue of Guitar World where Kirk Hammet was going on about warm-up exercises. He learned this one from a physical therapist after he broke his wrist while skateboarding back when he was a teenager.