That would appear to be true - I adopted 5 14-year olds and they are now 43. I've only permitted one of the males, who happens to be a runner, to have offspring. Not one of 12 ofspring likes running.
With another village, I started with 5 runners age 31 or younger. Two of the women died, only one of whom reproduced, leaving me with two men (now age 45 and 50) and one woman (age 31). They've had 5 offspring and none like running.