Are you serious? Surely you know that a 14 year old child is not emotionally or physically equipped to be in a relationship with a 20 year old, or to give consent to a sexual situation, which is mostly illegal depending on where in the world they are. If someone cannot consent — it is abuse. The child may not know they are being abused, and may classify it in their mind as a consensual “positive” relationship, but that doesn’t mean it’s not abuse. To discuss it in the way that you and Coyne are shows a complete lack of awareness around issues of consent (and frankly basic human morality). I’m pretty flabbergasted right now to even be having this conversation.
And I was rather hoping ME/CFS patients might be a bit more understanding than the none-too-bright psychologists of the letter, but reading your response, alas no luck. So let's try to explain carefully:
First of all, you need to distinguish between legal and moral codes, and the actual psychological circumstances of such a relationship. Whether you or your society think that a relationship between a 14 and 20 year old is right or wrong is not relevant to the scientific and psychological question of whether an emotional trauma arises from such a relationship. If you cannot logically separate these two issues in your mind, then you've failed at the starting line.
If a 20 year old has a relationship with a 14 year old, you may if you wish class that as immoral or illegal. (If you do, that's usually a parochial reflection of the country and culture you are from, because other cultures have different moral and legal views. For example, in some Islamic cultures, females can marry at 9). But rightly or wrongly, such relationships exist, and the question is whether there is always actual emotional damage and abuse, or whether such relationships might sometimes be relatively nice for the participants, and not lead to emotional trauma.
And let me spell it out clearly for you: nobody, is condoning a relationship between a 14 and 20 year old. You seem to think people are condoning such relationships, but that's because you have got the wrong end of the stick, and you have totally misunderstood the situation. So these relationships are not being condoned. But like it or not, such relationships have occurred and will occur. The question then is whether such relationships always lead to emotional trauma or not. This is a scientific question, not a moral question.
Have you now grasped the scientific nature of this situation and question?