i believe its something that can most definitely be fixed...there are absolutely millions of parents out there with children with behavioural issues..especially at this age.. there are a million reasons children play up in this way..eg..changes in circumstance..as you said what they watch on tv..or how there friends behave..etc. keep an eye on his patterns and what triggers his tantrums and if you still none the wiser then maybe seeking help down medical avenues for conditions like ADHD,or Autism..keep at it and best wishes
I don't know if it's something that can be fixed per say, but you can work on it. My 6 year old daughter has tantrums very much like this (and has autism). She screams, runs, and throws things. It is hard to get her to calm down. We came up with some calming strategies with her therapists. We use weighted blankets, time outs, and calm talking. No matter what be consistent. If you say no to something and he throws a fit, NEVER give in until he's calm at a later time. Even if he does have autism he can learn that good behavior gets him what he wants. We also got her a service dog who helps calm her down when she's upset.