He was a spoilt pampered brat, who in typical John Hughes style spoilt pampered brat ways, hated his parents. Logan aint too far removed from the Cameron Fry character from Ferris Bueller!!

He named BUB after his father, who was a doctor too. And was rich! His father didnt approve of Logan doing "purely research", saying there was no money in it. Logan's father must have been ashamed of his son, and the boys at his club (maybe one of them exclusive old world style clubs with butlers and cigars over port in the library and no women allowed, or maybe, a lodge style club where he wore one of the funky little Fez style hats. Like "The moose lodge" or something. You guys figure that out) probably teased old man Logan about his uncouth, wayward son who didnt appreciate his station in life. Old money i'm guessing too.

On the tape, Logan is having flashbacks about his overbearing, dominating mother. She'd be the typical housewife in pearls and pleated skirt who makes her husband a martini as he walks in the door. In relation to his family, Logan was helpless and hopeless. He only felt power butchering up zombies. As he says about Bub "I ALLOW him to exist". There was no love in Logan's family. Only prestige, and keeping that prestige up.

Logan felt no empathy with anyone. Chopping up the soldier who died meant nothing to him, in fact, he was flippant, saying to Sarah "he's more help to us dead than he was alive". Logan didnt fear the end of the world by ravenous undead - he relished it! Welcomed it! He probably felt his research could lead him to be, in effect, "king of the zombies". HIs own personal army to do his bidding against all the bullies in his life.

Logan is/was just like Norman Bates from Psycho.