Researchers in child development psychology, more specifically a study done by Donna M. Kovacs, Jeffrey G. Parker and Lois W. Hoffman (1996) looked into children's cross sex friendships, and found an absence of these types of friendships at younger ages. This raised cause for concern within the study as the researchers discussed how this could be due to a greater separation of genders at younger ages, which can reinforce societal defined gender roles, and prevent these types of friendships, which can be beneficial to development from occurring.