The thesis is a prediction about the main cause, in other words, about the first order effects. It does not exclude different lower order effects which are as far undetected. It is the null hypothesis in two directions: First, it predicts no difference between adults and children - for adults, unwanted sexual experiences are harmful too. Second, it makes no difference for between different types of unwanted experiences - physical or sexual violence.
This thesis explains most negative impact by a single cause - the trauma of unwanted childhood experiences. Thus, it is very simple and should be preferred by Occam's razor. It is the null hypothesis about the differences between children and adults: what is harmful for adults - unwanted, uncontrollable, unpredictable experiences - is harmful for children too. It is also the null hypothesis about the type of unwanted experience - physical violence is as harmful as sexual violence.
Of course, the thesis gives only a first approximation. There may be other, second order effects. Current research seems unable to detect these lower order effects.
Nobody denies that nonconsensual sexual experiences may be harmful, especially for children. But in the abuse literature, we can often find statements that also consensual experiences can cause such diseases. I have started to look into the related medical literature to find out if these statements are correct. My literature research is far from being complete, but up to now in coincidence with the assumption that consensual sex is not harmful. The results of this research you can find here.
We observe an absence of results about negative impact of volitional sexual relations. But there is no reason to assume that there has been not been enough research in this domain.
Instead, the leading abuse specialists know the problem, and they know about the political importance of this problem (see, for example, Finkelhor's response to Bauserman (1990)). They have had an interest to find such negative impact.
Moreover, most of the original research data, of course, would have allowed to make conclusions about volitional relations too. The fact that there are no results about the harm of volitional sexual relations is therefore strong evidence that no such harm exists.
That's why I don't see any necessity for further research. The thesis of negative impact of volitional sex with children is a hypothesis without any empirical base, it is a presupposition based on anti-sexual ideology.
Some part of the research mixes volitional and unwanted sexual contacts. This is a strong methodological failure. In any case, even if volitional sex is harmful too, the mechanism of harm and the probable impact would be probably different. According to our assumption, such research underemphasizes the impact of unwanted sex, because the really harmful unwanted sex is mixed with harmless volitional sex. In the average, the harm caused by unwanted ses looks less serious.
Some of this research ignores the use of force and coercion, but considers other dependencies (age, intensity, incest or not, gender, ongoing or not). Now, it is easy to guess that the probability of unwanted sex vs. volitional sex increases if the power difference becomes greater, thus, for incest and for girls. Of course, ongoing and more intense unwanted sex causes more harm.
Thus, for such mixed research we predict: In the average, it shows less harm compared with the studies about unwanted sex only. They show more harm for girls, for incestuous relations, for ongoing relations, for more intense relations.
I hope, this collection ordered by disease may be useful for various people. not only for the verification of this hypothesis. There is a long list of possible harmful outcome of sexual abuse. It seems necessary to consider every such topic separately. Here are some of them there I have already found something:
Let's start with the results collected by David Finkelhor:
For me, the aim of this research is not only to verify, that there are really no results which establish harm caused by consensual experiences (this has been done already by other researchers), but to allow you to verify this by yourself without going into the library.
I hope, this will be useful not only for people who want to find out if and which harm may be caused by consensual sexual relations, but also by others, like victims of real child abuse who want to find information about possible lasting effects.
I recognize that I have a personal bias - I'm not interested in finding
results which show damage caused by consensual sexual experiences. To
minimize the influence of this bias on the results, I try to include a lot
of the text of the original, and at least the abstract of every relevant
paper. This requires a lot of time, much more than simply to verify for
myself that there are no "critical" results in a given paper. That's why at
the current moment only a small number or papers has been included. But I
have not "selected" between "good" and "bad" papers. I know, I cannot prove
this until I have included them all, but I hope you believe me in this
point.
Summary
There is a lot of literature in this domain, and I have not so much
time as I want to spend for this. But already at the current state it
seems possible to summarize:
Negative outcome is mostly found only for women. Considering the fact that coercion and violence is much more common in man/girl relationships compared with man/boy relationships, this gives additional evidence that only the nonconsensual experiences cause the problems.