Once kids sense preferences you have, it creates enmity between them. I experienced it and it made me sad as we re all grandchildren. However because our God is the same yesterday, today and tomorrow, he worked it out somehow for my own good. I became the most well behaved, trustworthy, responsible and intelligent in the family an din not time my grandparents' favourite and my grandma's confidant.
I have learnt that in most cases we do pass our experiences to our children. I have 2 sons but I realise that my feelings for the elder have been adversely impacted by his performance as per my expectations. I do ask God to be merciful and help me to appreciate that he is different from me and the younger one. Involving, training and giving room for kids to be different and make mistakes is important as it helps to appreciate them closely. The challenge is that we tend to be drawn and love those people who are more like us.
I still need guidance on this matter though.