Didn't have to be taught by anyone. Instinctively learned to eith accelerate or slow down to merge smoothly.
Many times have to contend with the Guy in the right lane speeding up or staying abreast so you have to stand on the brakes. Accelerate and he does the same. One reason I like driving the little black car. I can accelerate faster than them or slow down easier and then merge.
I've had semis seemingly trying to force me to stop on the ramp. In the pickup it isn't going anywhere fast. Press it to the floor and thaat is the slowest acceleration.
The other angle, people figure you will slow down or stop to let them in. Now days many/most are on the cell phone and clueless. We can't find the horn when we want to, the way they are on the steering wheel these days. Experienced lots of purposefully dangerous drivers too. We just have to be cautious especially, in places like Atlanta, Chicago, ElPaso and so on.