to regular 1st Grade that the younger students are a zillion times kinder than Middle School aged kids. That really does make a big difference. When I had 6th Grade the students were so mean and cruel. One student even told me she wondered why she was alive. That set me off all that weekend since she implied she was going to harm herself. I consulted experienced teacher friends and the principal and practiced a speech for the bullies. She had been bullied since she was unusual...on the autism spectrum. The other students were also jealous since she was so super smart and beautiful. I read the worst offenders the riot act on the following Monday amd some even cried. Their own parents thanked me since the meaner students were even belittling the special student to their own families during dinner. The bullying stopped ASAP!
I always stuck up for the under dogs in my classes. With 1st Grade this wasn't much of a problem. I think they learn to be mean bullies as they get older and care more about what their peers are doing and saying. That changes around the 3rd Grade.
One thing I did notice was that ADHD and OCD are often confused in that certain behaviors overlap. The brain is an amazingly complex puzzle.