Christopher M. Earls

Viewing time as a measure of sexual interest

Abstract Based on the hypothesis that unobtrusively measured viewing time reflects sexual interest, it was predicted that viewing times should correlate with ratings of sexual attractiveness and with phallometrically measured age and gender preferences. Four additional predictions were derived from the Symons (1979) evolutionary theory of human mate preferences: (1) male and female subjects should view slides of young adults of the opposite sex longest and adults of the same sex and prepubescent children of both sexes the shortest, (2) the correlation between viewing time and sexual attractiveness ratings should be higher among males than females (3) males should look at slides of pubescent females longer than females look at slides of pubescent males, and (4) males should look longer at adult females than females look at adult males. Two studies involving 24 heterosexual females and 58 heterosexual males provided statistically significant support for all predictions except the last one.

A psychosocial study of male prostitution

A semistructured questionnaire was administered to 50 male prostitutes and 50 nonprostitutes matched on age, sex, and socioeconomic status. The questionnaire focused on areas pertaining to family, sexual and criminal history, current life situation, sexual practices with clients, substance abuse, etc. In addition, the Beck Depression Inventory and the Tennessee Self-Concept Scale were administered to 35 subjects from each group. Results indicated that there were differences between the groups but that these differences did not entirely support the demographic profile offered by previous researchers. Specifically, our findings suggest that factors related to family background may be less important as potential determinants for entry into prostitution than influences related to financial gain, sexual orientation (homosexuality), and early sexual experiences.

The Modification of Sexual Preferences

The modification of inappropriate sexual preferences is of central concern in many treatment programs for sex offenders (Abel, Becker, Cunningham-Rathner, Rouleau, Kaplan, & Reich, 1984; Borzecki, & Wormith, 1987; Griffiths, Quinsey, & Hingsburger, 1989; Marshall, Earls, Segal, & Darke, 1983; Quinsey, Chaplin, Maguire, & Upfold, 1987). This focus on inappropriate sexual interest follows from repeated observations that sex offenders, such as child molesters, rapists, and sadists, frequently report ruminating over sexual fantasies involving the types of behaviors in which they engage; moreover, the relative amount of sexual arousal elicited by deviant and nondeviant cues in phallometric assessment more consistently differentiates sex offenders from other males than any other measure yet tried (see Earls & Quinsey, 1985; Quinsey, 1984a, 1986, for reviews). The clinical importance of inappropriate sexual preferences is reflected in the definition of sexual deviations or paraphilias in DSM-III-R as disorders characterized by intense sexual urges or sexually arousing fantasies involving inappropriate objects or coercive sexual activities (American Psychiatric Association, 1987).

A Comparison of Three Methods of Scoring Penile Circumference Changes

There are presently three widely used methods of scoring penile circumference data. The present experiment attempted to determine the ability of each method to explain the variance within a data set. A total of 19 subjects were presented with 20 photographic slides assigned to five categories: neutral, female adult, female adolescent, male adult, and male adolescent. Erectile responses to each slide were recorded and the data analyzed in terms of the raw scores, percentage of full erection, and a z-score transformation. Results indicated that the z scores captured the highest proportion of the variance (52.7%), followed by the percentage scores (32.5%), and the raw scores (30.1%). Findings are discussed in terms of their research and clinical implications.

The Differentiation of Intrafamilial and Extrafamilial Heterosexual Child Molesters

It is unclear whether intrafamilial and extrafamilial child molesters differ in their sexual interest toward children and adults. Some authors have reported that both intrafamilial and extrafamilial offenders show sexual interest in children; others have found that intrafamilial offenders evidence little interest in children. The authors compared the phallometrically measured sexual interests of 19 intrafamilial heterosexual child molesters, 20 extrafamilial heterosexual child molesters, and 18 heterosexual nonoffender men recruited from the community. Stimuli consisted of 27 audiotapes describing either consensual sex with an adult partner, sexual contacts with a child using different degrees of force and violence, nonsexual aggression against a child, and neutral interactions. Nonoffenders showed a clear preference for adult stimuli; intrafamilial and extrafamilial child molesters did not discriminate between the adult and child categories and showed very similar arousal patterns.

The Effects of Exposure to Filmed Sexual Violence on Attitudes Toward Rape

This research investigated the effects of sexual violence presented in feature-length films. One hundred ninety-three university students (87 males and 106 females) were randomly assigned to view one of four films: (a) sexual aggression against a male (Deliverance); (b) sexual aggression against a female (Straw Dogs); (c) physical aggression (Die Hard 2); or (d) a neutral film containing no explicit scenes of physical or sexual aggression (Days of Thunder). After viewing the film, all subjects were asked to complete a 252-item questionnaire consisting of one of four randomly ordered presentations of the following measures: the Acceptance of Interpersonal Violence Scale, the Rape Myth Acceptance Scale, the Attraction to Sexual Aggression Scale, the Buss-Durkee Hostility Inventory, the Marlowe-Crowne Social Desirability Scale, the Mehrabian-Epstein Empathy Scale, and a movie rating questionnaire. Participants then viewed a reenactment of a rape trial and completed a 23-item rape trial questionnaire. Results showed large and consistent differences between males and females; that is, males were more accepting of interpersonal violence and rape myths, more attracted to sexual aggression, less sympathetic toward the rape trial victim, and less likely to judge the defendant as guilty of rape. Of particular interest was the finding that males were equally affected by a film depicting sexual violence regardless of victim gender. On the other hand, females were not affected by film type.

Birth Order, Birth Interval, and Deviant Sexual Preferences Among Sex Offenders

We investigated whether birth order and birth interval are associated with phallometric responding among 168 sex offenders. Based on the immunoreactivity hypothesis, we predicted that a larger number of older brothers and a shorter birth interval between the offenders and their next older brothers would be associated with more deviant responding. Results showed that a larger number of older brothers (but not older sisters, younger brothers, or younger sisters) was associated with more deviant responding on the Most Deviant Index, a general measure of sexual deviance. A larger number of older brothers was associated with arousal to nonsexual violence against women and children, but contrary to expectation, the same association was also found for the number of younger brothers. A short birth interval with the next older brother was associated with greater relative arousal to nonsexual violence, but the correlation with the Most Deviant Index did not reach statistical significance. Overall, results were consistent with the main predictions, but the effects of birth order and birth interval were mostly restricted to arousal to nonsexual violence. Birth order and birth interval were not associated with pedophilic interests or gender preferences.

The evaluation of olfactory aversion for a bisexual pedophile with a single-case multiple baseline design

Although a number of studies have examined the effects of olfactory aversion, the results have been donfounded with other treatments. The present expriment attempted to assess the unique effects of this treatment technique in the reduction of deviant sexual arousal using a single-case multiple baseline design. The subject was a young male having a history of sexual aggression against both male and female children. Assessment, using measures of penile tumescence, indicated high levels of sexual arousal to sexual and nonsexual violence with children of both sexes. When treatment was directed toward arousal to male children, penile responses to this stimulus category quickly decreased to below 20% of a full erection; arousal to female children remained at almost maximal levels until directly targeted in treatment. The results at posttreatment assessment indicated that olfactory aversion was effective in reducing deviant sexual arousal; these effects were maintained at one-year follow-up. The findings are discussed in terms of their experimental and clinical implications.

Male and Female Prostitution: A Review

The literature on male and female prostitution includes research from such diverse areas as law, medicine, psychology, sociology, and womens studies. However, one of the major efforts throughout this interdisciplinary area of study has been to describe the psychosocial characteristics of prostitutes. The assumption underlying these efforts is that such descriptions will lead to a better understanding of the general phenomenon of prostitution. The present review suggests that conclusions based on the currently available literature are limited by major methodological and conceptual problems such as: a) the failure to operationalize or to agree on the criteria for defining subtypes of prostitutes; b) faulty subject selection methods; c) the absence of appropriate comparison groups; and, d) an almost complete separation of research and theory according to the sex of the prostitutes studied. Nevertheless, there appears to be a number of variables that differentiate between prostitutes and nonprostitutes. Each of these factors is discussed and some suggestions for future research are outlined.

A case study of preferential bestiality (zoophilia).

Humans show a wide array of sexual preferences and behaviors. Although most humans prefer and have sex with consenting adults of the opposite sex, some individuals have unconventional preferences with regard to the sex or age of sexual partners, or with regard to the nature of sexual activities. In this paper, we describe a rare case of preferential bestiality, or zoophilia. The client meets the most stringent criteria for the diagnosis of zoophilia. In particular, his phallometrically measured arousal pattern shows a sexual preference for horses over other species, including humans.