K.G.
Hi K.,
Don't want to alarm you but this is a good time for intervention. My older son was very much the same...only child (at the time) and we (unconsciously) spoiled, coddled, etc. When I was pregnant with my 2nd we thought we should get him in some social settings in preparation for pre-school. Results: 1) Gymboree, same as you - not interested, ran around on his own, and knocked kids down, 2) Mothers Morning Out at church - kicked out, too rough for other kids, 3) Sibling Class at the hospital - kicked out, hit another child. After he started pre-school (Early Childhood 3yr olds), we heard from the teacher - daily. What an extremely stressful time in my life that was. However, there is light at the end of the tunnel. We had my son evaluated by his normal pediatrician, a licensed school psychologist, and a child psychiatrist. He was shown to have a higher than average IQ, and a moderate level of ADHD, with an emphasis on the "H"! Now before everyone starts shooting me down for what people still think is some...y2k, over diagnosed term for a bratty child, who should just be switched to whole foods...I say "walk a mile in my shoes". For us, finding the right medication along with counseling/therapy (for us!), was a pure gift from God. My son is now in 4th grade at the same private, Catholic school as he was in EC3 and has done wonderfully, he has all A & B's, excellent behavior, and a cub scout.
I used to think back then, “there is no way he is ever going to make it here in a Catholic, mainstream environment.” It is a miracle that he is doing so well. And yes he still has to take medication, however he requires a lesser dose as he is getting older.
Of course, this may not be anywhere close to what you are experiencing but I felt compelled to write, just in case I could be of some help. By the way, back when he was in EC3 and I broached the subject of Montessori school as well, one thing that everyone (from teachers to my doctor) told me was he does not need less structure, he needs more. He needs to learn what acceptable behavior is in mainstream society, not a more relaxed environment. Food for thought. Good luck.