A new study published in the journal "Child Development" has found that parents often show bias in sibling rivalry situations, favoring the younger child. The study analyzed data from over 1,000 families with two or more children and found that parents were more likely to intervene in favor of the younger child when there was a conflict between siblings.

The researchers suggest that this bias may be due to the fact that younger children are often seen as more vulnerable and in need of protection. They also found that parents were more likely to show bias when the siblings were of different genders, with mothers favoring daughters and fathers favoring sons.

The study also found that parents were more likely to intervene in sibling rivalry situations when they were feeling stressed or overwhelmed. This suggests that parents may be more likely to show bias when they are not able to cope with the demands of parenting.

The researchers conclude that parents should be aware of their potential for bias in sibling rivalry situations and should strive to treat all of their children equally. They also suggest that parents should seek support from other adults when they are feeling stressed or overwhelmed, as this may help them to avoid taking sides in sibling conflicts.

Here are some tips for parents on how to avoid bias in sibling rivalry situations:

* Be aware of your own potential biases.

* Try to treat all of your children equally.

* Don't compare your children to each other.

* Praise each child's individual strengths and accomplishments.

* Set clear rules and expectations for your children.

* Be consistent with your discipline.

* Seek support from other adults when you are feeling stressed or overwhelmed.