Board Thread:Lore Discussion/@comment-28157605-20160704151728/@comment-26145872-20170317212030

The Altmer described them as "They burn bright but quickly." I assume they're referencing to the fact that Bretons are excellent mages and capable of learning on par with the Altmer, but are limited by a short human lifespan in the eyes of a Mer, who live for hundreds if not thousands.

I agree that Bretons have a slightly increased lifespan or ordinary Men, judging from Tiber Septim who reached 108. For those asking, yes, I did the research myself and was able to prove that he is of Breton ancestry.