When it comes to caring for elderly parents, daughters offer as much elderly parent care as they can, while men often do not provide much care to elderly parents, according to a new study. The study indicates that sons often provide care depending on the presence or absence of others.

Angelina Grigoryeva, study author and a doctoral candidate in sociology at Princeton University, said in a statement, “Whereas the amount of elderly parent care daughters provide is associated with constraints they face, such as employment or childcare, sons’ caregiving is associated only with the presence or absence of other helpers, such as sisters or a parent’s spouse.”

The study results indicate that daughters provide 12.3 hours of elderly parent care on average each month, in comparison to 5.6 hours for sons. Grigoryeva explained, “In other words, daughters spend twice as much time, or almost seven more hours each month, providing care to elderly parents than sons.”

Additionally, the study suggests that when care for elderly parents is divided up among siblings in mixed-sex sibling groups, gender is often the prime factor in the amount of assistance provided by each sibling.

According to Grigoryeva, “Sons reduce their relative caregiving efforts when they have a sister, while daughters increase theirs when they have a brother.” She continued, “This suggests that sons pass on parent caregiving responsibilities to their sisters.”

According to the Administration of Aging, there were 39.6 million older adults, ages 65 and older, in 2009. By the year 2030, there will be roughly 72.1 million older individuals in the U.S.