He was born in September, 1925, that makes him 82. The article has been corrected. I remember reading a book about the case, in '71 he was in his mid-40's but looked much older. He had bought a palatial home at the urging of his wife but couldn't afford it. His kids were normal but List, his mother, and his wife were weird. He was morbidly rigid in morals, pathologically conservative (he wore a suit even when mowing his lawn), completely out of place in the 20th century, I mean even Mennonites would have thought him backwards.
His wife was heavily dependent on sedatives and sleeping pills and not of much use while his mother was the ultimate nag. A nightmarish atmosphere for the kids, his daughter was basically responsible for keeping house, cooking meals, shopping for groceries, tending to both her parents and her younger brothers, all the while attending school and taking acting lessons if I recall well.
List was definitely a psychopath of the religious delusional variety but didn't see himself that way which made him very dangerous.