(1) "Sibling height and muscle mass: A study of genetic and environmental factors" (Journal of Pediatrics, 2015)

On the other hand, it can also foster a sense of admiration and respect for the younger sibling's abilities. Older siblings may learn to appreciate and support their younger sibling's strengths, leading to a stronger and more positive relationship.

On the one hand, it can create a sense of insecurity and competition, particularly if the older sibling feels like they're being surpassed. This can lead to feelings of inadequacy and low self-esteem.