Saiyan-Earthling Hybrid Tail Chances

[Dragon Ball Gus]

The Saiyan Tails. They're one of the most distinguishable things about the Saiyan race, what makes them stand out from Earthlings. Of course, in later time, they were almost completely forgotten about. Okay, that's a bad word to say, cause obviously Toriyama remembers them, he didn't completely forget them like he did with certain things. *cough* Lunch *cough* But anyways, jokes aside, what I meant to say is that they were left in obscurity. As a result, that made wonder about why certain Saiyan characters don't have them, particularly Goten, Trunks, Pan and Bra. People have wondered why they don't have tails, considering the fact that Gohan, a Saiyan similar to them, did have a tail when he was little. I was one of those people. But when thinking about this topic, it made me think of a pretty theory that I'm sure you guys would like. What if the chances of Saiyan-Earthling hybrids having a tail depend on if their Saiyan Father (or Mother if you want to go that route, but we haven't seen Half-Saiyans be born from Female Saiyans) having a tail or not? Well, what do you mean by this Gus, I hear you ask? Well, what I mean is this. As we know, at the times when Gohan, Goten, Trunks and Bra were born, Goku and Vegeta didn't have tails. As a result, this probably meant that the chances of them having tails were very low. Pretty much a 25% chance of them having tails and a 75% chance of them not having tails. Gohan fell into the 25%, and Goten, Trunks and Bra fell into the 75%. But let's say Goku and Vegeta did have tails when their children were born, that means that the chances of them having tails would be much higher. A 50/50 chance. That means we could've seen either Trunks or Bra with a tail, now that could've been interesting. So that's the Half-Saiyans (Gohan, Goten, Trunks and Bra) out of the way. What about Quarter-Saiyans? What are the chances of Pan having a tail? Eh, they're much lower than with Half Saiyans. Pan's chances of having a tail are pretty much 10% and the chances of her not having a tail are 90%. That's because of the fact that Gohan doesn't have a tail. But let's say he did have a tail, then it'd pretty much be the same as Half Saiyan's chances when their Saiyan Fathers don't have tails. And as the generations go by, the chances of tails become more and more less almost to the point of them having zero chances of having one. So there we go. That's my theory on Saiyan-Earthling Hybrids' chances on having Saiyan Tails. What did you think of my theory? Did you like it? Do you have your own theory?

[theherodjl]

Toriyama has already clarified that Saiyan tails are a recessive trait as more Earthling/Human DNA is introduced & becomes dominant. There's always still some chance that descendants of Saiyan & Human offspring can have tails but however much more Human DNA is mixed in causes it to go down regardless of whether the parent had a tail or not prior to conception.

[dbgtFO]

Toriyama stating it's a recessive trair is Toriyama making up boring lore on the spot.
In a later interview he stated that the tail naturally refrains from regrowing, because they are so strong now IIRC.

It would make more sense, if that trait was passed on to their newer offspring and that's why Goten, Trunks, Pan and Bra don't have tails and have it easier with attaining Super Saiyan(at least in the boys' cases).

[Kaboom]

I like to think it has to do with those mysterious S-cells. In most cases, having a tail prevents S-cells from building, and vice-versa having a high S-cell count will prevent tails from regrowing.

Gohan is the only one of the demi-Saiyans born to a parent with a low S-cell count (18/19-year-old Goku with his PL of only a few hundred, still a LONG way from becoming a Super Saiyan), so he ended up with a tail. But all the others — Trunks, Goten, Pan, and Bra — were conceived when their dads had either already become Super Saiyans or were very close to it. So they ended up without tails, but in exchange have S-cells out the wazoo so Super Saiyan comes more naturally to them. Or at least it should, in the girls' cases.

[BWri]

Toriyama stating it's a recessive trair is Toriyama making up boring lore on the spot.
In a later interview he stated that the tail naturally refrains from regrowing, because they are so strong now IIRC.

This is the stuff me and my buddies used to say jokingly when talking about things in shonen anime that don't make sense. Example: "Didnt the main character just get poisoned by an attack that can melt his insides in seconds. Why is he still alive 40 minutes later?" "He is too strong. He is much strongerer than the poison!" "Wait, why can that other guy survive a direct attack to his heart?" "He has the demon blood of Atoo to make him more strongererest than any heart attack." Or the instant classic line in Super, "He's stronger than time!" It begins to sound like two children fighting with their toys trying to convince the other why their favorites are better except in this case it's a man trying to explain away nonsensically why he doesn't want to draw tails anymore.

*Sigh* in-universe, my guess would be that they've been surgically removed after birth. Bra and Pan are swaddled up after being born so we can't see if they had them. I'd want them removed too to avoid being Grandpa Gohan'd. And no, I'm not using Toriyama interview lore, because none of this was hinted at or mentioned in the show.