Don't usually go point by point with replies so doing so here might be less than optimally formatted but bear with me.
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Emily asked, "How can you expect to measure the full effects when so much of this is unconscious indirect influence?"
Studies carried out around the world include some checking results after decades have elapsed. I rely on these to draw conclusions from. Namely,
Legalizing child pornography is linked to lower rates of child sex abuse
"Diamond and team looked at what actually happened to sex-related crimes in the Czech Republic as it transitioned from having a strict ban on sexually explicit materials to a situation where the material was decriminalized. Pornography was strictly prohibited between 1948 and 1989. The ban was lifted with the country's transition to democracy and, by 1990, the availability and ownership of sexually explicit materials rose dramatically. Even the possession of child pornography was not a criminal offense.
The researchers monitored the number of sex-related crimes from Ministry of Interior records – rape, attempted rape, sexual assault, and child sex abuse in particular – for 15 years during the ban and 18 years after it was lifted.
Most significantly, they found that the number of reported cases of child sex abuse dropped markedly immediately after the ban on sexually explicit materials was lifted in 1989. In both Denmark and Japan, the situation is similar: Child sex abuse was much lower than it was when availability of child pornography was restricted.
Other results showed that, overall, there was no increase in reported sex-related crimes generally since the legalization of pornography. Interestingly, whereas the number of sex-related crimes fell significantly after 1989, the number of other societal crimes – murder, assault, and robbery – rose significantly."
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Emily asked, "Look at the increase in reports of rapes of drunk people being filmed on cell phone and posted and shared by others!
How do you know that behavior isn't related to oversexualization and DESENSITIZATION?
How are we supposed to trace ALL the influences that went into that behavior?"
Law makers don't factor in every conceivable implication or consequence. Be ncie if they tried as you put it here, but when we try and fight crime via the legal system sometimes we have to use whatever we have. If it doesn'tthen address every conceivable outcome like your's asked, the best we can hope to do is do so when they then arrise.
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Emily asked, "What about internet cyberbullying, blackmail and stalking? Forcing young people to send or post more and more explicit photos of themselves once the blackmailer has some dirt on them and threatens them if they don't comply?"
This problem is comparatively new. So new in fact I haven't even begun to address it (mostly because I have yet to buy a smartphone.) So whether pornography exposure to these kids with such devices and technology is having an impact is impossible for me to say. Though I"d assume it does. But even if it is, you don't forbid or deny or make illegal things because of how it might effect other things and issues. As with the 2nd Amendment. We have that despite pleanty of evidence guns are getting into the hands of criminals and the mentally ill. Just as we may eventually allow minor access to pornography despite some evience there are negative consequences of such access.
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Emily asked, "What about child porn and trafficking? If the effects are to feed addictions by adults, doesn't that have an effect on child victims?"
Read this several times and I'm not entirely sure what you meant but I'll wing it. I think you were asking wouldn't availability or legalisation of child pornography exaccerbate child sexual abuse like sex slave/human trafficking?
Statistics say no. Because oriignally child pornography was legal in both the US and some European and Asian countries, we have actual statistical evidence for what its effects were. And quite counter-intuitively, when child pornography was made illegal, child sexual abuse went up, not down. That said, actual pornography involving real children is abuse in and of itself. But modern computer animation (CGI/3D versions) can now depict human beings so convincingly that simulated pornography can meet the needs of those unwilling or unablet o fulfill their desires, predilictions, or addicitons for real as with pedophiles and those into things legal but bizarre (baby/pony roleplaying et al.)
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Emily asked, "Delta, if you want to do a study,
why not compare the attitudes and health of relationships of children who were brought up with
* teaching sexuality openly but with an emphasis on committed healthy partnerships vs.
* teaching sexuality without teaching kids the DIFFERENCE between ABUSIVE relationships
Then you can do a longterm study, showing the effects of
* sharing pornography with kids that does not show committed relations, and does not teach the difference between that and open sexuality with any partners or multiple partners
* sharing marital erotic or couples pornography, even swinging, where there is still an emphasis on consensual relations, within committed partnerships or marriage."
These studies have been conducted numerous times already. Think I just pulled this all out of my hat?

There's no point linking to the tens of thousands of studies since ultimately there's no reason to believe me, my asseritions, or any particular website. It's up to the ones who disagree to find a source they actually do believe and then come back with that. If it's legit science (vs religious fundamentalism) it might sway such assertions as I have.
Googling, 'long-term studies on childhood exposure to sexuality' there's 8.8 million. Ready, set, go!
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Emily asked, "Delta you should know that for scientific methods to work, there has to be an isolated control group, and also control the VARIABLES so you can compare the two groups.
I think you should know better than to try to interpret results from whatever is reported, without any controls of what is going in and data being collected from what cases/sources.
Anyone can derive anything you want to assume, if you conducted a study this way!
Really, Delta?
You seem smarter and more conscientious than that!"
I'm not posting data collected from some supermarket tabloid Em'. If it's not a scientific journal or university or other source I've actually heard of I"m VERY reluctant to use it. Because of how much work has been done of these topics there's no inability on my part to find scholarly and legitimate scientific sources for my claims. And that's where they all come form. Other than that, I grant your premise.
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Emily concluded with, "How do you think you can possible contain all the effects of sexualization and pornography?"
It's not about containment or forseeing every eventuality. It's about implemented policy scientists and psychologists, and social workers have told us actually work. Not clinging to dogma that's been im place long enough to see that it doesn't.
Child sexual abuse is a growing problem, and not just ebcause there's more people or more technology enabling the means of doing such abuse. It's because as a society we're valueing the wrong things.
- Why is it acceptable for children to handle firearms with their parents but not enojy sex with their friends?
- Why do we glrify violence calling it patriotic, m,acho, brave and heroic, while condemniung sexuality which is natural, beautiful, rather a lot of fun, and something everyone eventually desires? No ones dreams of being mugged or becomming a victim of violence, but everyone dreams about having good sex. Yet we condemn one, and say how great the other is.
- Why can a teenager drive a car endangering other people at age 16, but in many US states can't be trusted to make an informed decision to have sex until 17 or 18?
This is the stuff I worry about. We're ass-backwards in what upsets us. And for myself I'm not inclined to let the issue lie and not challenge it by discussing such things.