Through play and other interaction with their older brothers and/or sisters, young children learn skills such as conflict resolution and empathy, which can aid them in future social situations. However, older siblings remain prominent influences well beyond early childhood. They teach younger children how to act around friends and how to handle other peer-related situations. Older siblings may introduce their younger siblings to possible friends and provide outlets for continued socialization.

In many cases, older siblings play a role in the academic achievement of their younger brothers and sisters. Older siblings may motivate younger ones to succeed or provide help with homework or other scholastic endeavors. Older siblings play an especially large role in this regard in households where the parents work and the younger child is often in the care of the older siblings. Younger siblings are likely to model the study habits of their older siblings in any family.

Delinquency, risk taking and other problem behavior in children can be deterred by older siblings who are positive role models. If a younger child looks up to his older sibling who does not engage in delinquency, risk taking or drug use, he will be less likely to adopt these behaviors. For a younger sibling who does experiment with these behaviors, an older brother or sister can give helpful advice as to how and why to avoid future mistakes.

Older siblings can also be negative influences on a younger child's behavior and attitude. A study conducted by Jessica Craine and colleagues that was published in the 2009 edition of the Merrill Palmer Quarterly found that girls who looked up to their older, delinquent brothers were more prone to delinquent behaviors. Bullying is another way that a younger child can be negatively affected by an older sibling. Abuse or bullying by a sibling could result in social and/or emotional problems for the younger child.