Sisters serve as confidants, mentors, sources of support during intimate conversations

"Our findings indicate that sisters play important roles as adolescent girls form ideas about romantic relationships and sexuality," said Sarah Killoren, an assistant professor of human development and family studies at MU and the study's lead author. "Sisters are important communication partners when it comes to these sensitive topics."

Killoren says that older sisters should be included in family-oriented programs designed to help teens make better choices, such as abstaining from intercourse, practicing safe sex or developing healthy romantic relationships.

Killoren found sisters most frequently played the role of confidant. Sisters displayed this role by giving information about themselves and by asking for more information about their sisters' lives. The disclosures made during their conversations revealed levels of intimacy between sisters, Killoren said. The second role, sources of support, was displayed when sisters encouraged their siblings' ideas about dating and sexuality. The mentor role was displayed when sisters served as role models for one another, most frequently by giving advice.

"Given their age, older sisters were more likely to have advice to share and have romantic relationships and sexual experiences from which their younger sisters can learn," Killoren said.

Younger sisters commonly reported learning from older sisters' experiences, especially their older sisters' negative dating and sexual experiences, Killoren said.

"Younger sisters frequently commented on their older sisters' negative experiences, such as teen pregnancy and abusive relationships, and made decisions to be different," Killoren said. "Learning only from negative experiences could occur because younger sisters only consciously identify the experiences of their sisters that they do not want to repeat."

Sisters share similar views on dating and sex, which is partly because they have grown up in the same home, Killoren said.