Siblings Good for Each Other (IMAGE) Brigham Young University Caption Something about having a sister -- even a little sister -- makes 10- to 14-year-olds a bit less likely to feel down in the dumps according to research by Brigham Young University. Credit Mark Philbrick/BYU Usage Restrictions credit Mark Philbrick/BYU License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.