This weekend, Mada is looking after her nephews Vera and Ibai, aged nine and six, respectively. Her sister-in-law, the children's mother, is preparing for competitive exams, so she's using Saturday morning to study at the Ignasi Iglesias-Can Fabra library in Sant Andreu, while Mada takes the two children and her seven-year-old daughter, Ona, for a walk around the neighborhood. At midday, the children and their parents will all gather at Mada's house for lunch. Although they live in different neighborhoods and each cousin has a different circle of friends, both families try to see each other often. "We alternate Saturday lunches between our house and theirs," explains Mada, who emphasizes how the three children enjoy the evening the most. They also occasionally babysit for the children. "That way, the parents can enjoy some free time when we need it or when we feel like getting away without the kids," she notes. These are moments that Mada considers ideal for enriching their relationship and doing different things, "but also for learning about other routines and ways of doing things, and for them to understand that every family can have different customs and rules." In the summer, Mada's family spends the season with their caravan at the campsite, and sometimes Ona receives visits from her cousins. "All of us being there, sleeping together and playing and running around the campsite in semi-freedom is quite an adventure!" she emphasizes. Mada and her brother—Vera and Ibai's father—are from Cantabria, so during the summer they also take the opportunity to visit family. "Our other brother and our nephews David and Regina live there, and although we don't see each other as much as they'd like, when all five cousins ​​get together it's fantastic," she explains.

I hadn't seen it coming that my children would fight all the time. I'm an only child, and of course, I had no idea this would be a constant feature of sibling relationships. In our house, you can always hear shouting, and someone always calls the other "Stop it!" You can imagine that, with four boys, they almost always play roughly, they're always hitting each other, and what starts as a game often ends in a huge drama. Are there siblings who calmly play chess all afternoon? Or do they make recipes with the hope of being the new Roca brothers? Well, not mine. Mine argue, get angry, and say all kinds of things to each other. And is this thing about siblings always like this? I asked, completely naively, people who have siblings. Yes, it's always like this.

"Families should be aware that the relationship between siblings, beyond encouraging it to be the best possible, will depend on the personality of each sibling," says Estrella Ferreira, a professor at the Faculty of Psychology at the Autonomous University of Barcelona (UAB). Each sibling has their own personality and interests, but doing things together that everyone enjoys can be encouraged, so as not to weaken the relationship. Maria Helena Tolosa, teacher, psychopedagogue, trainer, and author ofOur daily conflicts, agrees: "It's a bond that deserves respect, but they don't have to be friends. The relationship between siblings has a degree in itself, which is different from that of friends, although if both come together it's wonderful."

He's present every day. He's simply part of the family. For some, he's become unattainable, distant, and absent; for others, he can be a rival or even a hindrance that forces them to learn to share. A sibling is and always will be a sibling, but this figure loses all meaning when it lacks the most important thing: the bond. An affinity that ignores age variables because there can be a great difference but, at the same time, great cohesion; or there can be disinterest, rivalry, and competition, yet they can be only months apart. And when siblings aren't blood relatives? The realities of separated families (or other types) add new variables. What doesn't change—and never will—is that the bond between siblings depends, in and of itself, on many factors, and that, in these situations, the parents—who have a lot to say and do—become a pillar that tips the balance toward a context of conflict or resolution.