I’ve ridden four generations of one of my geldings, and three generations (different line) of another, along with various other relatives (uncles, cousins, for instance). For the four generations one (I’ve ridden members of both the maternal and paternal sides of the family), they’ve all had great-grand daddy’s kind, friendly temperament, with very similar builds – although plus or minus a couple inches on the height, and varying colors dues to his dilute color genetics – and his same head, eye, and expression, plus similarly wonderful canters. No one would doubt that they were relatives.
But they differed slightly in how much they tended to anticipate, the degree of work ethic (no duds, but some were more of a volunteer type while others waited to be asked, then cheerfully cooperated), and in other gaits.
For the other gelding, his maternal great-grandfather had been the result of a brother/sister mating (not by me), with the next two generations greatly resembling the GGF (who produced a large number of offspring). But my mare, who followed the family tradition of being an obvious descendant of her dad and grand-dad, produced offspring that resembled their respective sires, not her nor their maternal grandmother, in their appearance and in gaits.
Temperament-wise, they were (are) kind, sweet horses, but without what I consider her paternal lines no-nonsense, workmanlike tendencies (she couldn’t be drilled, for instance, if she did something correctly once or twice, it was time to move on to something else, then come back to it later).
The gelding from this mare that I still own is the spitting image of the paternal side of his family, to the point that, when I took him to a clinic when he had only been under saddle a few weeks, the clinician – a BNR familiar with bloodlines – knew his breeding when he stepped off the trailer and called him a clone. The photos and videos of paternal relatives that I saw bore this out.
I’ve enjoyed seeing the similarities and noticing the differences in the relatives I’ve ridden (several of which I’ve owned), and I think my personal knowledge of, and experience with, their families has helped me understand my horses better.