The only known genes that give an inborn tendency to violence/antisocial behaviors are those affecting the right prefrontal cortex and 1-2 affecting the limbic system, particularly the amygdala.
However, having those genes does not mean that the person will grow up to be a killer. At all. In fact, one of the men who discovered the relationship between the genes for the right prefrontal cortex and antisocial behavior is a doctor. He himself has the gene. You can look him up on youtube. He used fMRI studies and genetic studies to establish the connection (he wasn't the first, but he certainly rethought his own inner life and his relationship to his own right prefrontal cortex, which is the part of the brain that lights up when people ponder moral dilemmas). There is variation in its size and function. The original studies were done on people on death row.
That guy also states that probably the main reason why he's pretty normal, has been in the same relationship since age 12, etc. is because he had great parents and a very healthy upbringing. His name is James Fallon BTW.
I know some people get personally offended for some reason at the idea that past exposure to violence and trauma can increase the risk of criminal behavior, but sorry, that's what all the research says. You're not going to find any researcher in psychology, neurology, etc. saying someone is "born to kill" and their background or environment is irrelevant. It's simply just not factual. There is a large body of research on this topic.
The no plan is why I feel like they didn’t have permission to take the camper truck or they told KM’s parents a different story of where they were going.
Definitely possible.
I think they were stopping places and maintaining relatively decent hygiene during the joyride part of their trip, especially for teenage boys. I've mentioned this before, but they're wearing clean-looking clothes in the video. They've not been driving in those clothes for days without a change.
Their hair also doesn't look oily, Bryer looks pretty clean shaven, and even Kam's beard, though longer than in "normal" pics I've seen of him, isn't that wild looking on his jawline. Nobody reported them appearing disheveled or dirty-looking.
So, I don't find it that odd they weren't covered in mud. I'd say they stopped somewhere and cleaned up. It also wouldn't surprise me if they changed clothes that day for that reason. I also have suspected Bryer had multiple pairs of camo clothes--seems like a look he was fond of.
Also weren't they in the store later that afternoon while the mud odyssey was in the morning? I think they had time to clean up.
MOO
Also, neither of them appear to have any acne in the store footage (that's very high quality camera footage). They must have been washing semi-regularly...I just wonder where.
We do not know this for a fact. If you have info source please.
We don't but so far no known criminal records or family/friends talking about any past criminal activity have come up. In fact family has said quite the opposite, that they were shy quiet gamers who didn't start fights or anything. Unless something comes up indicating they did have a criminal history, I'm going to assume they didn't, since it probably would have come out with all the other stuff.
There there is nothing in any report that they were actively using alcohol or other drugs on any kind of regular basis.
There isn't, but it's JMO that drugs or alcohol were likely involved based on the general picture of the crime we have. Bryer had a picture with alcohol on his Instagram and there was also the famous account of the "Nazi Ritalin party," so I doubt they were straight edge.
Unrelated as they were not mass shooters.
Not unrelated. As I said they fit the psychological profile of mass shooters almost exactly, which likely indicates similar motives if not similar execution. But you're welcome to look up the info yourself on the links between all types of violence and past exposure to violence and trauma...it holds true for all types of violence.