No two individuals are alike, and hence no two individuals will repress emotions in precisely the same manner.  To avoid  getting too technical, here is an analogy for what I think may be happening. Imagine a small river or stream with a dam  across it whose sluice gate is normally always open, allowing the water to pass freely downstream.  This is Emotion River,  and "downstream" it will eventually flow into the child's Ocean of Conscious Awareness if permitted to do so.  Now supposing that as a result of a physically painful, degrading form of parental punishment, the child, on a still-unconscious  level, experiences a strong wish to murder the parent in retaliation for this massive betrayal of trust by the care-giver and  toxic insult to the child's dignity and bodily integrity. This would be comparable to a toxic spill "upstream" from the dam.  The  hatred flows downstream towards the dam like any other emotion heading towards conscious recognition (i.e. the "ocean").  But, for reasons already stated, the child cannot allow THIS emotion to reach the ocean and become conscious.  So he or she closes the sluice gate and dams up the river.  Prevented from flowing within its usual course the river will  soon begin overflowing its banks upstream from the dam.  The "banks" of the stream correspond to alternate emergency  neural pathways for mediating the banished emotion.  The place where the river water first starts overflowing will be the place where the bank is lowest.  This is another way of saying that the threshold of this particular pathway is lowest. Once water begins flowing out of the riverbed at this spot, though, it will quickly begin eroding a new channel out of the riverbed and into the surrounding area.  The more emotions are repressed, the more the new channel is "worn in" thereby increasing the likelihood that future repressed emotions will follow the same pathway.  This corresponds to the increase in neural connectivity of a pathway with repeated use.  The areas surrounding various portions of the riverbank correspond to various brain circuits, each of which will respond in distinctly different ways when saddled with the unusual emergency task of absorbing and mediating repressed emotions.  The more emotional water flows through this new channel, the more permanent the channel becomes.  In other words, once a child's "alternate pathway" of repression becomes established early in life it becomes more and more permanent with repeated use as the child grows up and as his or her brain gradually loses plasticity.

    What makes one section of the riverbank "lower" in one person and a different section of the riverbank "lower" in someone  else?  In other words, why are people's individual thresholds different?  I propose that this is the result of genetic  variability between individuals and that additive genes regulate the "height" of the various sections of the metaphorical  "riverbank."  This means that, if this hypothesis is correct, there should be genetic correlates to different neural strategies  for dealing with banished emotions.  This is potentially testable via statistical genetics methods.

    Although such definitive research has yet to be performed, some smaller studies of twins have shown some preliminary  evidence of possible genetic correlates to fetishisms.  Gorman (1964) found remarkable similarities in the fetishistic  fantasies and behaviors among his sample of identical twins.  Unfortunately, his study did not include a sample group of  fraternal twins as a control for the effects of similarities in the rearing environment.  Gosselin and Wilson (1980) found an elevated concordance for S& M tendecies in their sample of identical twins when compared with a sample of fraternal  twins.  However, the sample sizes were small, and further research is needed to rule out the possibility of statistical  artifact.

    A child who "acts out" repressed hatred will be more likely to become violent, aggressive or spiteful.  This hypothesis  would predict that the more such children are spanked, the more they will act out, and tragically, the more they act out, the  more they are spanked - a vicious cycle.  Prospanking parents typically fail to recognize what is happening and what they  are doing to their child because spankings temporarily stop the offending behavior (thereby negatively reinforcing spanking behavior in the parent and giving the parent the illusion that spankings "work" on their aggressive child).  Hence this  hypothesis predicts that the children who are spanked the most, as a group, will grow up to exhibit the highest statistical  likelihood of exhibiting violent aggressive behavior in adulthood as well.  When large representative population studies have  looked at criminal behaviors and childhood corporal punishment, this correlation is exactly what they have found (Straus, 1991).  The more a child is spanked, the higher the statistical likelihood that they will perpetrate repeated and severe  assaults on siblings; for physically abused children, (who presumably have an even heavier repression "load"), this correlation is stronger still (Straus, 1983).  Spanking in the home also correlates with higher statistical likelihood of aggressive behavior against kindergarten peers (Strassberg, et. al. 1994).  The more often a former child was spanked,  the higher the statistical likelihood that they engaged in both violent and property crimes in high school (Straus, 1985; Gelles  and Straus, 1990), and that they physically abused their spouse or children, as adults, in the previous twelve months  (Straus, 1983).

    This hypothesis predicts that people who were rebellious, defiant, "bad" children are statistically LESS likely to be spanking  fetishists than the general population, because their "riverbanks" "overflowed" in a different area of the "river."  In the case  of spanking fetishists, the "lowest" point of the metaphorical riverbank allowed a new channel for the repressed emotions  to flow onto what Money (1986; 1987) calls the "lovemap," a neural template mediating the precise elements which lead to sexual arousal.  The young child's brain  is highly "plastic" and the developing lovemap will grow neural connections in response to environmental stimuli ("imprintability").  If, due to the additive effects of specific genes, the area around the river  corresponding to the lovemap is "flooded" when emotional repression first occurs, future repressed emotions will also  tend to follow this same pathway and the developing lovemap will take on the shape and form of such banished emotions.  If humiliation was a traumatic issue in the child's life, humiliation will become an erotic stimulus to the child in fantasy.  If  spankings were a traumatic issue, the fantasy of a spanking will become an erotic stimulus, and so on.  Since such  children are coping with repressed hatred by "acting in" rather than "acting out," this model predicts that a disproportionate  number of spanking fetishists will report having been compliant, "good" children.

    Tension arising from repression must be discharged.  The "bad" child discharges it by acting out.  The "good," spanking  fetishist child discharges it by masturbation.  The budding spanking fetishist will not experience as much parental  disapproval as his or her more rebellious siblings, but will typically experience a great deal of guilt and shame. Negative  messages about masturbation and sex in general may well contribute to this guilt, but I suggest that the feeling of shame  comes from a deeper source and may typically originate well before the child is able to become aware of and internalize  negative messages about sexuality and the genitals.  Guilt, in my view, is not an emotion in and of itself, but rather a  disguised form of fear.  The fear, in this case, is the fear of loss of parental love.  This could explain why so many fetishists delurking on internet forums report having felt while growing up that they were "bad" or "wrong" for  having their particular fascination with spanking, even though they were never actually told that such an obsession was  a "bad" thing.  This latter fact is clear from the large number of such delurk posts in which the writer reports having  thought as a child that they were "the only person in the world" with such fantasies.  Clearly, if they thought they were unique, no one could have told them that "people who have sexy spanking fantasies are bad" because such an admonition  would reveal that other such "bad" people do exist in the world.  In some particularly sad cases, discovery in adulthood of the internet-based forum was the first evidence they had ever encountered of the existence of others like  themselves.  This means that throughout their childhoods and into adulthood, many of these individuals must have carried around a sense of isolation, guilt and shame which could not possibly have benefitted them on their developmental  journeys.  I propose that this sense of shame arises because repressed hatred of the spanking parent is at the root of their  sexual fascination with spanking.  This hatred feels on an unconscious level like a wild animal which, if let out of its erotosexual "cage" would surely either kill the parent or cause the parent to hate and reject the child in return.  The fear of  losing the parent is experienced in disguised form as guilt about the spanking-oriented fantasies.

    Meeting other spanking fetishists, if only on-line, constitutes a form of peer-group-therapy which, judging by testimonials online, has helped a lot spanking fetishists better manage their guilt and reduce its power.  But the subtlest forms of such guilt and self-loathing may never entirely disappear.  For example, I suspect that spanking fetishists who accuse other people of having the same desires as themselves, as if this were some sort of crime, are acting out of a residue of  precisely this kind of intractable, lingering, self-loathing.

    I think that avoiding raising one's children to be spanking fetishists is a good reason not to spank children.  It is not that I view some particular set of sexual semiotics as intrinsically inferior to any other.  It is because I believe that at least some forms of spanking fetishism are the direct result of traumatic repression caused by childhood spankings.  Hence, to say "don't spank your kids because you might turn them into fetishists" is really just an abbreviated way of saying "don't spank your kids because this can evoke unintegratable emotions of hatred which your child will be forced to repress and which they may then cope with by eroticizing your spankings and spending the rest of their lives feeling frustrated because their pool of available sexual partners is so small, and feeling guilty and ashamed because of how your maltreatment of them made them hate you back when they were helpless and dependent upon you."

    The issue is, ultimately, not the prevention of spanking fetishes, but the prevention of trauma.