Who's the Favourite?: The Loving, Messy Realities of Sibling Relationships

by Catherine Carr

The first book to explore the joys and complexities of adult sibling relationships
'Whether you're a sibling or an only child, Catherine Carr's book will leave you wiser and feeling more at home in the world.' Oliver Burkeman

For most of us, our sibling relationships are the longest we will ever have. Whether loving or fraught, competitive or codependent, these bonds shape us in lasting ways.

In this heartfelt, judgment-free book, Catherine Carr invites us to look at our brothers and sisters beyond the labels assigned in childhood. Combining real-life stories with expert insight, she explores birth-order stereotypes, favouritism, trauma, blended families, only children, siblings with additional needs, and the pain of estrangement and bereavement.

These relationships are rarely straightforward but thinking about them more deeply may help us better understand ourselves and the world around us.

*Interwoven with candid interviews with sibling pairs taken from her hit podcast, Relatively, such as Chris and Xand van Tulleken, Johnny and Lillie Flynn, Nick and Gill Hornby, Manni and Rueben Coe, and more*

'Truly enlightening, charming and moving.' Jane Garvey

'Brilliant.' Dame Jenni Murray

'Hilarious, moving and fascinating.' Chris and Xand van Tulleken

Genres: Nonfiction, Psychology, Self Help

336 pages, Kindle Edition

Published March 19, 2026

Reviews

[Donna Williams · Rating 3 out of 5]

I’m the youngest of 3 sisters and I’ve always been fascinated by discussions around birth order. The author introduced some new concepts to me: the idea of vertical vs. horizontal sibling relationships and something called “glass” siblings. It was interesting to know that when there is a loss of a sibling, the grief of the sibling(s) left behind is often not addressed and not tended to. The focus tends to be on the parents when there is a loss of a child. That was eye opening for me!

I enjoyed when the author shared specific details and dynamics within her own family. I would have wanted more specific scenarios and less passing references to studies done by “Dr so and so” and what “Dr so and so” said. My overall impression is that I should check out Catherine Carr’s Podcast “Relatively” - I might enjoy that even more than this book.

[Patricia · Rating 5 out of 5]

Really interesting. I wish it had gone deeper into some of the studies cited (very curious about the methodology on some), but I understand the book is trying not to be too technical. I learned a lot.

[Katie Salmon · Rating 5 out of 5]

A fascinating and empathetic look on sibling relationships in all shapes and sizes.

[Charlotte · Rating 5 out of 5]

Fantastic. Insightful, intelligent, funny and deeply moving, this is a totally charming book that will gently lead you to consider sibling relationships in an entirely different light.