Karl Pillemer of Cornell University in Ithaca, N.Y., and Jill Suitor of Purdue University and colleagues analyzed data of interviews of 275 mothers in their 60s and 70s with at least two living adult children. They also surveyed 671 of the women's offspring.
"Perceived favoritism from one's mother still matters to a child's psychological well-being, even if they have been living for years outside the parental home and have started families of their own," Pillemer said in a statement.
"It doesn't matter whether you are the chosen child or not, the perception of unequal treatment has damaging effects for all siblings."
The findings were published in the Journal of Marriage and Family.