I guess its always in our nature to compare our children to others despite the fact that all children develop at different paces. My two eldest girls developed at what seemed to be exactly the same pace as each other..ie their babbling, rolling, sitting, crawling, walking. I got the shock of my life when my youngest daughter was so different. She started crawling at 12 months and didnt walk til 17 months. I had the same concerns as you..needlessly i should add. She was just herself and developed at her own pace. Olivia is exceptionally bright..overlapping my 9 year old daughter in all areas of cognitive learning...so i just think she was taking her time and taking it all in. Please dont worry unnecessarily. Im sure your gorgeous little boy is perfectly fine.

Jo