Yes, my mother favors oldests..........two of her three grandchildren. Our littlest one is shortshrifted sometimes. My father, I suspect, would favor boys, but there are no granddaughters, so can't test the theory (he favored my brothers over me, and had done the same with his first set of kids).
My father in law prefers our oldest son as the oldest grandson. He did the same with his children, with my dh being the preferred one. My mother in law doesn't seem to have preferences.
My grandmother showed clear preferences and tiers. First came the youngest daughter's children, then my mother's, then the oldest and middle son's and the middle daughter's last. My grandfather didn't like any kids past about the age of two.
My father in law prefers our oldest son as the oldest grandson. He did the same with his children, with my dh being the preferred one. My mother in law doesn't seem to have preferences.
My grandmother showed clear preferences and tiers. First came the youngest daughter's children, then my mother's, then the oldest and middle son's and the middle daughter's last. My grandfather didn't like any kids past about the age of two.
). Partially, it is distance- we live 5 hrs away from my parents, and 9 hrs from DH's parents. My brother lives about 30 mins away from my mom and dad, and DSIL lives 15 mins away from her parents. So, naturally, their kids see them much more often than we do.
They watch their cousins open BRAND new toys still in boxes. My poor babies. That was 20 years ago when the 1st was born and it still goes on.
Oh I hear ... you are preaching to the choir here! My MIL is so awful to me, even though she feels she is being a loving woman. even My hubby says I need to cut her some slack. FIL told me while I was preggers with our 1st child (21years ago) that our kids would not be welcome at his table. 
When youngest was 3 she piped up in that beautiful voice they have at that age "why does Grandma hate you Mommy?" 
