My take is that some degree of competition or comparison between siblings is healthy. The main thing I would take note of is not to always put a particular child down. Recognize the strength of each child and play to each one’s advantage at various points. Children, especially siblings, learn from one another and could benefit from such healthy competition. Growing up, I was often compared to my sister. While I didn't like it, I can't argue that she was more studious and my parents' comparisons highlighted a lot of her positive habits that I ended up learning. She became my role model. Also, there were times where my parents highlighted my good points to nag at my sister and that did feel good too. haha..
Also, I would suggest that instead of comparing between two children, you can also compare to yourself or daddy. Children love to model after their parents and it could be a great way to motivate them.
Just thought to share some of my personal experiences since I was at the "receiving end" of such comparison. Not sure if it is helpful but just my thoughts. :)
Read more