I got a friend who honestly believes things like "Putin is crazy because he wasn't showed any love as a kid." Aside from the fact that my friend believes the whole "PUTIN IS CRAZY" meme, the friend also mentioned that Hitler wasn't shown any love either...

Anyone have any resources that debunk this nonsense?

EDIT: I found this: https://www.thesurvivorstrust.org/FAQs/if-someone-is-sexually-abused-during-their-childhood-they-are-likely-to-become-an-abuser-themselves ("The vast majority of child abuse survivors will never perpetrate sexual abuse and are utterly appalled by the insinuation that they are capable of such an act")

EDIT 2: Also found this study: https://www.ojp.gov/ncjrs/virtual-library/abstracts/do-abused-children-become-abusive-parents:

Annotation

The belief that abused children are likely to become abusive parents is widely accepted, but the authors contend that this belief cannot be unconditionally supported.

Abstract

A review of case history, agency record, and self-report studies indicates that about one-third of all individuals who were physically abused, sexually abused, or extremely neglected will subject their children to one of these forms of maltreatment. The rate of abuse among individuals with a history of abuse is approximately six times higher than the base rate for abuse in the general population. Although this suggests that being maltreated as a child is an important risk factor in the etiology of abuse, most maltreated children do not become abusive parents. Many mediating factors affect the likelihood of intergenerational abuse. Consequently, unqualified acceptance of the intergenerational hypothesis is unwarranted.