Do the Robins really think of each other as siblings? I know they all consider Dick a brother and vice versa, but between all them, is there really a sibling dynamic/consideration? Do they ever call each other as such?
Okay, so, off the bat (heh) from the phrasing of this ask I want to clarify something:
Namely that the hero role of ‘Robin’ does not inherently have a familial tie.
‘Robin’ is a hero role that has (in main continuity) been filled by: Dick Grayson, Jason Todd, Tim Drake, Stephanie Brown, Damian Wayne, and in a slightly less formal way Duke Thomas (he was a member of the We Are Robin movement and the most prominently featured of that group, though he did not really act as ‘Batman’s sidekick Robin’ which is why he’s kinda in his own category here but still worth mentioning).
However, that’s not to say there are no familial ties there. From the list of Robins… Dick Grayson, Jason Todd, and Tim Drake are the adopted sons of Bruce Wayne. Damian Wayne is Bruce’s biological son. Duke Thomas was for a time fostered by Bruce, though that is not presently the case (he lives with his uncle instead nowadays). And, while not a Robin, it’s also worth mentioning that Cassandra Cain (Batgirl) is Bruce’s adopted daughter.
So, to answer the baseline question of ‘Do the Robins really think of each other as siblings?’ I would say 'most of them do, the ones that are adopted siblings'. But like, Steph isn't their sister, and they aren't her brothers. That’s simply not the case there, she's never been adopted by Bruce (not to mention one of them—Tim—is literally her ex-boyfriend).
I think it’s very safe to say that among the ‘Dick, Tim, Jason, Damian’ grouping, yes canon has pretty clearly shown that they do all have a brotherly dynamic. They don't all use the specific phrasing that frequently, but it's not uncommon for them to—whether to directly call one another brothers, or to talk about their shared (adopted or otherwise) dad. This isn't to say they are all close or all have good relationships with one another all the time (lol no, Dick & Tim are close/generally have a good relationship, and Dick & Damian are also close/generally have a good relationship, but aside from that things get rockier/vary a lot more) but at the core there's a brotherly thing with all the ups and downs that entails.
To pull some examples of either using that phrasing or showing that kind of dynamic from books published within the last few years:
(Dick & Jason in Nightwing (2016) Annual #1)
(Dick talking about Tim in Nightwing (2016) #80)
(Dick talking about Damian in Nightwing (2016) #110)
(Jason & Tim [& Cass] in Task Force Z #8)
(Jason & Damian Robin (2021) #5. I do feel the need to mention that on Damian's end this hug was also a distraction to then electrocute Jason. That's just how he is sometimes. but the hug was genuine on Jason's end 🤷)
(Tim & Damian [& Dick] in Batman #138)
That’s just some stuff I could think of off the top of my head, there’s definitely more examples (and also if I went further back, but I'm approaching this anon from a 'the current state of things' POV).
Also worth noting that Dick & Damian’s relationship does kinda toe a line between ‘brothers’ and ‘pseudo father-son’ due to Dick needing to fulfill a parental role while Bruce was dead (pre-N52, like, Batman and Robin (2009) era). They’re still more brothers than anything else, but with such a large age gap and the way responsibilities had to be taken due to the situation at the time, it makes things complex, ya know! In general, I think that’s something to keep in mind—it’s not that these guys all lived together as one happy family with Bruce at any given point in time (they did Not), but despite that they still are family. They each have a complicated relationship with Bruce, and complicated relationships with one another, but they are (and see each other as) family regardless. A messy and non-traditional family, but still a family.
The thing I think some people get confused with is the way that the greater 'Batfamily' is more what we think of as a 'found family' where characters don't necessarily fall into traditional familial roles... because that includes people like Barbara Gordon, Stephanie Brown, Helena Bertinelli, etc—people who are bats but are not part of the Wayne family. Like... The Wayne Family and The Batfamily are not synonymous. The Wayne Family is a separate but partially overlapping thing. The Waynes are Bats but not all Bats are Waynes, ya know? And like, it's only further confusing because of how most of Bruce's adopted kids kept their original last names even after adoption, so it's not always clear at a glance who falls into which group if you're not super familiar with the characters.
NOW, the person I think this gets a bit fuzzy with in terms of placement is Duke… he's obviously part of the Batfamily, but where exactly he sits in relation to the Wayne Family has like, been different at different points in time. Because he was Bruce's foster child for a while, and now he isn’t anymore. So in terms of his relationship with the other Robins, it definitely is more familial than like, Steph's relationships with any of the others—because he was their foster brother—but it's not quite as strictly defined as among the 'Dick, Jason, Tim, Damian' grouping. I’m gonna link this post by a Duke-centric blog which goes into some of this more clearly!
