There may actually be some science behind eldest daughter syndrome

Growing up as the eldest sibling, author YL Wolfe often felt as if the boundaries between her role and that of her mother were blurred.

"By the time my youngest brother was born, when I was almost eleven, I was overwhelmed with feelings of responsibility for his well-being. I would always sit by his crib and watch him sleep, just to make sure he was safe," Wolfe, the oldest of four, told HuffPost.

"It wasn't that ...