Is The Saying Blood Is Thicker Than Water True?

Yes, adopted children love their new parents, just as non-adopted children love their biological parents. Each family is different- There are people who grow up in families in which they are all blood-related, but they have little love to share between them. There are families with adopted children, and outsiders (and insiders) would be surprised to find that they are not blood related - the bond is that strong.

I don't think a biological connection overrides the emotional connection created between parent and child. I have heard many adopted children saying that they were curious about their birth mothers or fathers, and at some time in their lives, fantasized about being with them - but biological children do the same thing - fantasize about being raised by ideal parents. In the end, we all still love the people who raised us and were truly part of our lives.