Are present Trunks and future Trunks technically brothers rather than the same person?

[Muffin Man]

I mean, think about it. They canonically have different colored hair thanks to the retcon, they age at different rates (with present Trunks, much like Goten, aging at the slower saiyan rate rather than the faster human rate), and the circumstances leading up to their conceptions were different, what with Vegeta training for the Androids in the new timeline (meaning Vegeta would have impregnated Bulma with a different sperm).


All signs point to them being inter-timeline brothers rather than the same biologic individual.

[precita]

Yeaaaaah....I'm gonna go with "No" on this one.

They're the same person from two different timelines.

[nickzambuto]

Sure, why the hell not.

[Grimlock]

they age at different rates (with present Trunks, much like Goten, aging at the slower saiyan rate rather than the faster human rate),

But this is actually a problem, not an individual issue. Biologically speaking, they are the same, they have the same parents, they inherited the same genes, therefore they have to age equally. What happens externally is another subject (like hair color, for example, as it can be changed if the person wants. Actions; Future Trunks is the one who defeated Freeza, so you cannot give present Trunks a kill that he doesn't have). But internally they're the same, so... Present Trunks being smaller is a problem, not a unique characteristic.

Anyway, I don't think they are brothers. Sure they have their own characteristics (not height included) but that's common (?) when it comes down to beings from different timelines who lived different lives, but that doesn't make them two entirely different entities.

[Bulma's Foot Masseur]

Vegeta and Bulma's altered behavior before and during pregnancy would have notable impact, I think. Timing of growth spurts, ease of attaining Super Saiyan, etc. And Super Saiyan Rage could easily count as a mental disorder.

[Ki Breaker]

Same person, different ages/timelines

[floofychan333]

They aren't brothers in any way. They're just alternate versions of each other. If I met myself at age 30 then we wouldn't be brothers.

[Lord Beerus]

No. And there is nothing to imply that they are. They are simply from different timelines.

[Muffin Man]

And there is nothing to imply that they are.

But they are canonically physically different (different hair color and they age differently) and the timeline was altered before they were conceived. Even if they are genetically very similar, what we see on screen seems to indicate that they are not genetically identical.

[Jinzoningen MULE]

The timeline did split before Trunks was conceived, potentially changing the time Bulma's baby was conceived. That being the case, the available sperm and egg become variable. Going on that assumption, Kid Trunks could technically be a different person from Future Trunks.

Is that the intent? Obviously not. Does it make for fun headcanon? Absolutely!

[SkuLLR3D]

They're separate people with the same identity and biological makeup living in different timelines of universe 7

One can view them as brothers I suppose, but I see them as two different people.

[Dbzk1999]

No, it's essentially the same deal with Cable and Nate Grey, only difference is that Future Trunks and Trunks are born from the same mother (instead of one just being a clone of the mother)

[TheDevilsCorpse]

If you want to get overly technical, then yeah? I guess. At least as of Super. The intention is obviously supposed to be that they're the same person from alternate timelines, and that worked for the original run of the series. But Super has pushed really hard to establish that Future Trunks has always had blue hair, via the flashbacks. That would mean despite sharing the same parents, they're not genetically identical.

Again though, that's not the intention.

[The Monkey King]

The different growth rates and hair colour would imply yes.

[emperior]

Well, Super even mentioned the butterfly effects and if Trunks' altering of the story completely changed 18 and 17's personality it probably also affected the past Trunks' genes to a very minor degree, which caused changes such as past Trunks having a much higher starting potential, different hair color and a more Saiyan like growth pattern.
We know for certain that past Trunks is leagues above his future counterpart in terms of his potential when young, because he was shown to be near 18 or even Piccolo in terms of power, while the Trunks from the future was seen (at least in the manga) to be weaker or on par with a untransformed Gohan, who was weaker than the cyborgs at 50%, who as Future Trunks later stated where even weaker than the past ones.

[cheddarsword]

If you want to get technical about it, then this video may help understand the situation.

The Game Theorists: THE TRACER PARADOX! https://www.youtube.com/watch?v=bOweAfSv2-4

I know it's about Tracer from Overwatch but considering her Ultimate does for her essentially what Trunks did, I think it's applicable. And this video explains the situation.

Long story short, Trunks even going back to the past in the first place altered his own existence in that universe. The same person? No, that is physically impossible. But to call them brothers? I don't know if that's applicable either.

It's a sort of grey area.