Victims of rape and childhood sexual abuse frequently describe dissociation-like experiences which occurred during the assault. Typically, we assume that these are dissociative experiences. But are they? I don’t think we really know. To be blunt about it, we have little idea where our animal defenses leave off and our dissociative functioning begins.
Tonic Immobility During Rape
In my last post, I described the first empirical study of tonic immobility during rape. Galliano et al. (1993) reported that 37% of rape victims had experienced tonic immobility during the assault. Furthermore, tonic immobility during rape was not a blessing. Galliano and colleagues found that tonic immobility seemed to breed guilt and self-blame. As one member of our discussion community recently put it:
“I was an athlete; 21 yrs old, strong, feisty, self-assured. my experience of tonic immobility during rape [generated] an identity crisis that had me feeling profoundly confused about who I was and ashamed that I did not fight back. it took me a long time to fully understand this response as a defense mechanism and let go of the guilt I felt about not fighting back.”
According to Tiffany Fusé, almost half of women who experience tonic immobility during rape find it to be terrifying. As the quotation above illustrates, the autonomous intrusion of tonic immobility not only takes away what little power that a rape victim still possesses, it may challenge her very identity:
“Animals and humans do not choose TI [tonic immobility] … TI is more akin to a hardwired response, a response that can be quite frightening itself.” (Marx, Forsyth, Gallup & Fusé, 2008, p. 80)
“the TI experience itself might be so aversive and frightening that having such an experience promotes the onset of posttraumatic stress symptomatology.” (Marx et al., 2008, p. 84, emphasis added)
Uh oh — “promotes the onset of posttraumatic stress symptomatology?” That would go far beyond the old saw about ‘adding insult to injury.’ Marx and colleagues are saying that, in the case of sexual assault, tonic immobility adds injury to injury. Does it?
Does Tonic Immobility Generate Posttraumatic Complications?
In a word, “Yes.” Every study that has examined this issue reports the same finding: trauma survivors who experienced tonic immobility have more posttraumatic symptoms than do trauma survivors who did not experience tonic immobility. Let’s take a closer look at this finding.
The size of the correlations between tonic immobility and posttraumatic symptoms are consistently modest. With few exceptions, these correlations range from .21 to .37. This means that tonic immobility and posttraumatic symptoms share 4% to 14% of their variance. On the other hand, Fusé and colleagues (2007) factor analyzed their Tonic Immobility Scale and found two factors: (1) Tonic Immobility and (2) Fear. When Heidt, Marx, and Forsyth (2005) correlated the Tonic Immobility factor with a good measure of PTSD symptoms, they found a correlation of .49.
This begins to be rather impressive. Rape is known to be an especially potent generator of PTSD symptoms (e.g., Rothbaum, Foa, Riggs, Murdock & Walsh, 1992). Now, Marx and colleagues have shown that tonic immobility, all by itself, accounts for 24% of those symptoms! What is going on here?
Let’s take a look at “the internals.” What the heck are internals? Those of you who are major political junkies may know. On TV, when they present the latest poll results, they soon get around to “the internals” — the detailed numbers within the major result. For example, the poll may say that Obama’s positive rating is 48%. The most interesting stuff, however, lies in “the internals” — that is, Obama’s positive ratings among Democrats, Independents, Republicans, men, women, and so on. Similarly, the most interesting findings in these eight tonic immobility studies can be found in the internal details.
PTSD has three clusters of symptoms: (1) re-experiencing (e.g., flashbacks, intrusive memories), (2) avoidance/numbing (e.g., avoiding anything that reminds you of the trauma, loss of interest in daily life), and (3) hyperarousal (e.g., hypervigilance, jumpiness). The key internal result from the eight studies is that the relationship between tonic immobility and PTSD symptoms is mostly driven by tonic immobility’s effect on re-experiencing symptoms.
So, there is something about tonic immobility that can make a bad event (especially rape) more traumatic. There is something about tonic immobility that worsens flashbacks and intrusive memories. And by the way, some of these studies examined nonsexual traumas and found the same thing. Tonic immobility somehow makes trauma worse.
Bottom Line: Our gifts from evolution and Mother Nature are usually quite beneficial. Here, however, our phylogenetic inheritance (i.e., tonic immobility) may have some very unpleasant consequences.
And now, a Question: “Is tonic immobility an aspect of peritraumatic dissociation?” Or not? If not, why not? This may be an annoying or useless question for some of you. For me, it’s really important. Remember: I’m the guy who is trying to sort out the boundary between animal defenses and dissociation. So, what do you think?