The More Fun with Sisters and Brothers Program teaches 4 to 8 year-old children the key social and emotional competencies that research has shown are critical for fun, friendly and low-conflict sibling interactions.

https://funwithsistersandbrothers.org/

The Sibling Studies Network encourages, inter alia, those working with anthropological, educational, historical, psychological, scientific, and sociological perspectives to communicate their insights on siblingship across their disciplines, so as to enter into conversation with other approaches 

https://siblingstudiesnetwork.york.ac.uk/home