It is hinted throughout the series.Still,i'm not so sure...

Yes.
In the case of Gohan he has some rage potential that put him in the top tier.

He was the secret weapon of Goku to beat Cell.

At the end of the manga he don't need to transform in super sayiajin anymore because his potential was fully unlocked.

@realitywarper: I always wondered how much energy it would take or how powerful would Ultimate Gohan be if he tried to go super sayian.

Maybe

To be honest, this was an asspull, yes that its a term.

Also it looks the fact their parents werent normal average Saiyans, was big part of this.

But at the end, you notice the stronger characters were the pure ones.

I don't think so. They seem to be able to become Super Saiyans at a younger age though.

Stronger, I don't know, they seem to be born with higher power levels but they top out lower overall and their powers seem to develop faster.

Goten > DBZverse

Vegeta flat out says it

Seems mostly they have better overall potential.

However, they still need to train. Gohan is a perfect example of that.

By the way, do people consider Gotenks a full-Saiyan or still half? Or like maybe a third?

@scouterv:

He's half

1/2 saiyan + 1/2 saiyan + 1/2 human + 1/2 human still equals saiyan human hybrid

He's still 2/4 saiyan and 2/4 human

Half

I always thought so, Goten also had buckets of potential to be better than Goku and Gohan. But it was never realized.

In the back of my mind, I feel like I remember it being said that half-Sayians have the same potential as full blooded Sayians, but because they're Humans, they excel at reaching their potential faster (or something like that). It was why the more diluted the Sayian blood became with Human blood, the faster it seemed like the individuals became more powerful. Example; little kids flying around as super Sayians.