The contradictions of Henry VIII character have attracted much attention. He had a reputation for wisdom and patience early in his reign, and though adventurous was not known to be especially violent, and certainly not cruel. He became an unquestionable tyrant later. Historians during the 18th and 19thC tended to see these changes as a function of the temptations of power, and losing his grip on his better self because of not getting his way. That fit their beliefs. In literature since the Greeks and Romans, humans were prone to such temptations, and rulers were especially susceptible to deteriorations of character once they were unchecked. It is a common theme in Shakespeare and all subsequent European literature. Nothing wrong with that, it's often true. But they didn't really know how baps on the head might affect you once you had regained consciousness, so they never went to that explanation.
One traditional approach, favoured by (David) Starkey and others, is to divide Henry's reign into two halves, the first Henry being dominated by positive qualities (politically inclusive, pious, athletic but also intellectual) who presided over a period of stability and calm, and the latter a "hulking tyrant" who presided over a period of dramatic, sometimes whimsical, change.More recently, there have been suggestions that he died young due to the obesity caused by brain trauma, or that his personality was influenced by the draining effects of many medical conditions resulting from his several blows to the head and periods of unconsciousness, and finally a direct suggestion that his violence and impulsivity were clearly derived from his TBI's. They didn't think that way then, we think that way now. Taking more factors into account is usually better than fewer. (As we just discussed under Critical Race theory.)
Even in my generation, unless permanent results were very obvious, people did not ascribe behavior to brain trauma. Parents might be aware of it - "After that he was never quite the same agin, always losing his temper and getting into trouble." Yet parents are both the best and worst of observers of such things. They see that something is wrong even when everyone else looks away or attributes behavior to simple disobedience or other bad character. But parents also have too much information and their own needs, and so fit behavioral changes into any of a dozen categories: parental divorce, the emotional rather than physical effects of abuse, rejection by a girl, a bad teacher/pastor/school bully, competition with siblings. I have heard all these explanations offered by parents when taking a social history. We all fall into this naturally, as the brain will not endure having an unexplained phenomenon, and we jump to conclusions. Much of what I believe about how my children became who they are is likely only partly true. Many of their own explanations are probably similarly slanted, as are mine about why I am who I am.
Baps on the head are one of those things that fade from memory fast. We expect boys to be reckless, they take falls, they hit their head on rocks. Because ice is a factor in New Hampshire, my worst blows to the head were usually to the back. These injuries usually take place out of sight of parents or other adults. They were considered just a normal part of growing up. Getting assaulted by older boys, or sneak assaulted from behind by weaker boys, even with sticks or bats was also just considered part of childhood, unless something obvious and severe occurred.* Men and women in prison have an unusually high incidence of head injury, which we often write off as the environmental effect of "being exposed to violence," or "coming from a bad neighborhood." Yet while those things matter a bit, when we try to factor out all such factors they don't matter much. Measurable neurological changes matter a lot more, and have larger consequences. Like maybe a nation's split from the Roman Church and a division of Europe that has enormous consequences even in our own time.
It would be great if my bad qualities were the result of one or more of those incidents as a boy, so that I have "diminished responsibility," as they say. Yet that would immediately extend to everyone else, and it may be that the evils done to us were the result of actions by people who had diminished responsibility themselves. What societies have to consequate for their own survival may not be the most accurate measure of judgement.
There is a gene-environment interaction that goes even deeper. In families that have a lot of children showing risky behavior, so that we figure they can't all have been bapped on the head in exactly the same way and there must be some genetic risk-taking involved, those kids are going to just naturally have more head injuries, including repeated small, undetected ones. When they become teenagers and adults we are going to blame the parenting, and the courts are going to treat crimes as personal decisions. We might be wrong.
*This may also affect whether we perceive something as traumatic in an emotional sense. I don't like to go too far down the road of what is called "blaming the victim," but I experienced events at school for which I might have sued my children's school district had they happened to them, a generation later and in a gentler place. There was a comment-section argument a few years ago among women about sexual assault in which one woman who still lived in a rough part of town quoted a young woman from a suburb who was describing some aggressive behavior by a date and noted "At my high school forty years ago, we just called that dating." The younger woman may have been correct that it should be considered assault - I would have expected a call from the police myself had it been me - but clearly the older woman did not experience it as traumatic. Expectations matter, because they affect feelings of uncertainty and control. What children experience they immediately compare to the experiences of those around them. If Jeffrey next door got beaten up much worse than you, you didn't feel so bad about yourself.