Gender Differences in Autonomic Functioning and Anti-Social

¶ … gender differences in autonomic functioning and anti-social personality disorder features. Thus, the authors are not actually examining autonomic functioning in persons who have been diagnosed with anti-social personality disorder. The sample size is a small one -- one hundred undergraduates, the majority of which are white. Therefore, the results of the study have low generalizability and are basically invalid. The greatest value in the research is the fact that the authors suggest that there may be some gender differences in the way features of anti-social personality disorder find expression. These features of antisocial personality disorder include aggression. The authors validate the research by claiming that it fills gap in the literature related to anti-social personality disorder, even though the sample used in this study did not have anti-social personality disorder per se. Namely, the authors say that no published studies have examined autonomic correlates of anti-social personality disorder in women and that this research is at the very least a good start offering suggestions for future research.

The authors have two hypotheses. One is that there would be a gender difference in measures called hyporeactivity and hypoactivity, in that men were predicted to have decreased responsiveness and heart rates when they exhibited more features of anti-social personality disorder. The dependent variables are measured by heart rate and other cardiac indicators. Basically, heart rate has been shown to be influenced by the parasympathetic and sympathetic nervous systems. The parasympathetic nervous system generally reduces heart rate, while the sympathetic nervous system increases heart rate and is related to excitability. These two functions of the nervous system, parasympathetic, and sympathetic, function differently. The authors also use as a measure in this study something called "cardiac pre- ejection period," or PEP. PEP "refers to the time interval between the onset of the q-wave and cardiac ejection, and is inversely associated with cardiac SNS activity." In other words, more PEP means less cardiac sympathetic nervous system activity. The second research hypothesis was that antisocial personality disorder features would be positively correlated with less sympathetic nervous system action and more parasympathetic nervous system action in both men and women.

The methods used in this research are experimental. Participants included 100 undergraduates, exactly 50% men and 50% women. The study was conducted at a private Southern university. The researchers interviewed the participants and administered a questionnaire. After that, the researchers measured the dependent variables of autonomic system responses in a laboratory setting using various tests. During this laboratory phase, ten of the participant data sets had to be eliminated from the research, yielding only 90 participants in total. The vast majority (81%) of the participants were white, 11% Asian/Pacific Islander, 7% African-American, and 1% Latino. There was a small compensation including class credit offered to the students, but no mention is given about whether informed consent was used.

The interview measures used included the SCID-APD Scale, which is a standardized measure used for personality disorders. The questions are designed in accordance with the Diagnostic and Statistical Manual (DSM-IV) Axis II Criteria for the personality disorder. The questions are designed to be low threshold, meaning they are "intended to capture many false endorsements," (p. 89). This is so that the false endorsements lead to further questions related to the same criteria. Results are coded so that a criteria or symptom is clearly present or not present at all. Graduate students in clinical psychology administered the interviews.

Questionnaires used included the Aggression Questionaire, which has 34 items and uses a Likert scale. The Psychopathic Personality Inventory -- Short Form (PPI-SF) measures psychopathological traits using 56 items and a Likert scale. There were also several laboratory tests used in this study to measure the dependent variables. Those tests included the Countdown Task to assess passive coping and the International Affective Picture System (IAPS), which uses photographs. Other tests measured psychophysiological data such as Electrodermal Activity Level (EDA).

The results only partially supported the research hypotheses. Men scored higher on the SCID -- II APD scale, which does somewhat support the research that more men than women are diagnosed with anti-social personality disorder as it was found that the men scored higher than women on the SCID -- II APD scale. Researchers predicted that EDA hyporeactivity (decreased responsiveness) and cardiac PEP hyporeactivity (which refers to lengthened time required for cardiac PEP) in men, but not women, while anticipating an aversive stimulus are associated with APD features," (p. 89). This "partially" supported the research hypothesis (p. 92). The researchers' second hypothesis was that anti-social personality disorder features would be positively correlated with changes in PEP (less sympathetic nervous system activity) and RSA (more parasympathetic nervous system activation) in men and women, respectively, in response to visual stimuli of threatening or distressing situations," (p. 88). This second part of the hypothesis was disproved.

Because the results do not give any clear indication that the hypotheses were proven in a strong way, this study seems weak. Also, the authors admit that there were many flaws in the research design. For instance, there is a homogenous sample size of only undergraduate students at one university and most were white. Also, the results cannot be generalizable and are of questionable value. If the participants in the study were people who had been clinically diagnosed with anti-social personality disorder, then the results would be more helpful. It is impossible to know whether these results are useful for this reason. The participants were only given questionnaires to measure some of the features of anti-social personality disorder but not the disorder itself. Furthermore, it is questionable whether the results would have any value anyway. The authors do not explain why it is important that sympathetic and parasympathetic nervous system responses might different among men and women with anti-social personality disorder or with some of the symptoms of this disorder.