A new study looked at 6,838 families to figure out which kids are most likely to bully their siblings, and the answer is the youngest sister, she just can't stop torturing people. Just kidding. It's the oldest brother. OBVIOUSLY it's the oldest brother.

The researchers found that the oldest kid in a family is most likely to bully their siblings, especially if the oldest is a boy.

The study also found that families with more kids have more bullying. When there are only two siblings, there's less.

Read more at Science Daily.