New York, Oct 17 (IANS): A good relationship with a sibling promotes development of sympathy and levels of altruism in boys, says a study.

"Having a sibling you can count on seems to make a difference especially for prosocial behaviour," said lead author Jim Harper, professor at Brigham Young University (BYU) in Utah, US.

The findings suggest that having a sibling could be just as good for your boys as it is for your girls.

"In our study, most relationships were not as important for boys as they were for girls," study co-author Laura Padilla-Walker from BYU noted.

"But the sibling relationship was different - they seemed to report relying on sibling affection just as much as girls do. It's an area where parents and therapists could really help boys," Padilla-Walker pointed out.

However, the researchers found that boys who have a hostile relationship with a sibling were significantly more likely to have behavioural problems later on.

The researchers followed 308 pairs of teenage siblings for three years. The project measured their development and tracked the quality of their relationships with friends and family members.

"This was the first siblings study to control for all these other important relationships," Padilla-Walker said.

The message for parents is that helping their children have a positive relationship with each other will yield lasting rewards, noted the study published in the Journal of Research on Adolescence.