Saturday, June 1, 2019

Pornography & aggression, & sexual & relationship dissatisfaction: Studies reveal methodological bias in favor of findings for effects that disappear when better methodologies are employed

Fisher, W. (2019). 004 How Science Studies Pornography Impact and What Science Can, and Cannot, Tell Us. The Journal of Sexual Medicine, 16(6), S2. doi:10.1016/j.jsxm.2019.03.461

Introduction:Sexuality clinicians have been concerned about the impact of pornography on sexual behavior at least since Dr. Ivan Bloch’s declaration, in 1902, that “There is no sexual aberration, no perverse act, however frightful,that is not photographically represented today.” Historically, the US, Britain,and Canada have funded national commissions to investigate the presumed negative effects of pornography, and in very recent years, the US Republican party platform and the US states of Florida and Utah have declared that pornography represents a public health crisis. More recently still, the Canadian parliament launched an inquiry into the health effects of online pornography.

Objective:There is a widely accepted social, scientific, and clinical narrative to the effect that pornography is a pervasive cause of sexual aggression against women, relationship devaluation and deterioration, and cause of sexual dysfunction. This presentation provides an overview of four decades of scientific research on the effects of pornography with a view towards soberly assessing what science can, and cannot, tell us about the effects of pornography on sexual aggression, relationship breakdown, and sexual dysfunction.

Methods:The methodological approaches and findings of classic studies inthe areas of pornography and sexual aggression, pornography and sexual and relationship satisfaction, and pornography-induced sexual dysfunction are reviewed and critiqued.

Results:Careful methodological review of laboratory experimentation concerning pornography and aggression reveals staggering methodological bias in favor of findings for effects of pornography on sexual aggression that disappear when appropriate methodologies are employed. Similarly, findings for effects of pornography on sexual and relationship dissatisfaction appear tohave been exaggerated in close-ended research that focuses solely on assessing harms and are not replicated in open-ended participant-informed research approaches. Findings for pornography-induced sexual dysfunction are ambiguous and may be interpreted to mean that individuals are receiving access to idiosyncratically arousing content in pornography that is not otherwise available to them in setting in which their sexual function is suboptimal.

Conclusions:This overview of research calls attention to the need for scientific skepticism in evaluating widely shared but scientifically questionable conclusions concerning the supposed negative effects of pornography. Attention to methodological bias, failures to replicate, and recognition of conflicting findings suggest that the science does not support the conclusions with any degree of consistency. At the same time, we do see patients clinically who have significant problems with their or their partner’s use of pornography, and careful, clinically relevant science on the actual role of pornography in these presentations and effective treatment approaches that focus appropriately on causal factors remains to be accomplished.

Biological Bases of Beauty Revisited: The Effect of Symmetry, Averageness, and Sexual Dimorphism on Female Facial Attractiveness Seems Smaller Than We Thought

Jones, A.L.; Jaeger, B. Biological Bases of Beauty Revisited: The Effect of Symmetry, Averageness, and Sexual Dimorphism on Female Facial Attractiveness. Symmetry 2019, 11, 279.

Abstract: The factors influencing human female facial attractiveness—symmetry, averageness, and sexual dimorphism—have been extensively studied. However, recent studies, using improved methodologies, have called into question their evolutionary utility and links with life history. The current studies use a range of approaches to quantify how important these factors actually are in perceiving attractiveness, through the use of novel statistical analyses and by addressing methodological weaknesses in the literature. Study One examines how manipulations of symmetry, averageness, femininity, and masculinity affect attractiveness using a two-alternative forced choice task, finding that increased masculinity and also femininity decrease attractiveness, compared to unmanipulated faces. Symmetry and averageness yielded a small and large effect, respectively. Study Two utilises a naturalistic ratings paradigm, finding similar effects of averageness and masculinity as Study One but no effects of symmetry and femininity on attractiveness. Study Three applies geometric face measurements of the factors and a random forest machine learning algorithm to predict perceived attractiveness, finding that shape averageness, dimorphism, and skin texture symmetry are useful features capable of relatively accurate predictions, while shape symmetry is uninformative. However, the factors do not explain as much variance in attractiveness as the literature suggests. The implications for future research on attractiveness are discussed.

Keywords: faces; attractiveness; symmetry; machine learning; averageness; dimorphism

MSM: Relative to a full battery condition, participants were more likely to agree to a hookup in the lowest battery condition; those men also endorsed a greater propensity for sensation seeking

Smartphone Battery Levels and Sexual Decision-Making Among Men Who Have Sex with Men. Alex Lopes, Kaylee Skoda, Cory L. Pedersen. Sexuality & Culture, June 1 2019.

Abstract: Smartphone-dating and hook-up apps are undeniable factors in the modern landscape of sexuality. In particular, gay and bisexual men have bridged social and societal barriers for connection by using these apps. Despite advantages afforded by such technological advancements, when individuals are faced with a low phone battery, a sense of urgency may be experienced, which can increase risk-taking behaviours to accommodate an impending phone “death”. The purpose of this study was to determine whether a draining smartphone battery would facilitate a greater likelihood of agreeing to a hookup encounter. Participants were randomly assigned to one of three battery life condition groups (5%, 20%, 100%) and were asked how likely they were to agree to a hookup with a simulated potential sexual partner. We discovered that, relative to a full battery condition, participants were more likely to agree to a hookup in the lowest battery condition. Additionally, men who reported a greater likelihood of agreeing to a hookup also endorsed a greater propensity for sensation seeking, regardless of the battery condition. These findings have practical implications for educating smartphone users who utilize dating and hookup apps about how scarcity decision-making and sensation-seeking can impact the ability to practice safe sexual behaviours.

Keywords: Hookups Dating applications MSM Decision-making Smartphones

There are studies in humans and animals revealing that lack of adequate sleep may facilitate sexual arousal, including objectively measured erections

Costa, R. M. (2019). Sleep and Sexual Arousal: A Complex Relation. The Journal of Sexual Medicine, 16(6), 946. doi:10.1016/j.jsxm.2019.03.267

I congratulate Smith and colleagues for their study on the relations of sexual function and sleep quality in older people,1a topic that deserves great attention. Their findings in a large representative English sample are extremely interesting, but also intriguing. Compared with men with high sleep quality, men with moderate sleep quality had greater odds of having erectile difficulties, but men with low sleep quality did not. Moreover, compared with men who sleep 6e8hours, men who sleep>8 hours had greater odds of having difficulties attaining orgasm, but men who sleep<6 hours did not.1Ifwe think that longer and better sleep favors sexual function, as many studies suggest, these are intriguing findings. Smith and colleagues note that the “results indicate that the relationship between sleep problems and sexual dysfunction is not as simplistic as previously suggested (poorer qualitysleep = greater dysfunction)” (p. 431), especially when several confounds are controlled.1

In this letter, I call the attention to an often overlooked phenomenon in the research on the relations between sleep and sexual function. There are studies in humans and animals revealing that lack of adequate sleep may facilitate sexual arousal, including objectively measured erections. After sleep deprivation, men diagnosed with psychogenic erectile dysfunction improved their erections in response to erotica,2 and for both sexes, poorer subjective sleep quality over the past month correlated with self-reports of greater unstimulated sexual arousal, that is, arousal in the absence of external stimuli.3 This occurred especially among those with higher testosterone levels.3 Among men, awakenings during both rapid eye movement (REM) and non-REM sleep increased visual attention to pictures of women, as assessed by eye-tracker, but the non-REM sleep awakening also disturbed REM sleep,4 which makes likely that it is the specific inhibition of REM sleep that has enhancing effects on sexual arousal. This is confirmed by research showing that REM sleep deprivation stimulates spontaneous erections and ejaculations in rats.5 The potential of REM sleep deprivation for increasing sexual arousal might be due to increased dopaminergic transmission, and it may also occur in women.3 Shortage of REM sleep is a likely consequence of many sleep disturbances.

Plausibly, in many cases, this effect may be offset by tiredness, difficulties interacting with the partner, psychopathology that develops due to lack of appropriate sleep, and perhaps by lower testosterone levels,3 among other factors. However, its presence might account for the complexity of the relationship between sleep and sexual function, as noted by Smith and colleagues.1

The False Enforcement of Unpopular Norms: The authors argue that people enforce unpopular norms to show that they have complied out of genuine conviction and not because of social pressure

The False Enforcement of Unpopular Norms. Robb Willer, Ko Kuwabara, Michael W. Macy. AJS Volume 115 Number 2 (September 2009): 451–90.

Abstract: Prevailing theory assumes that people enforce norms in order to pressure others to act in ways that they approve. Yet there are numerous examples of “unpopular norms” in which people compel each other to do things that they privately disapprove. While peer sanctioning suggests a ready explanation for why people conform to unpopular norms, it is harder to understand why they would enforce a norm they privately oppose. The authors argue that people enforce unpopular norms to show that they have complied out of genuine conviction and not because of social pressure. They use laboratory experiments to demonstrate this “false enforcement” in the context of a wine tasting and an academic text evaluation. Both studies find that participants who conformed to a norm due to social pressure then falsely enforced the norm by publicly criticizing a lone deviant. A third study shows that enforcement of a norm effectively signals the enforcer’s genuine support for the norm. These results demonstrate the potential for a vicious cycle in which perceived pressures to conform to and falsely enforce an unpopular norm reinforce one another.

The adaptive problems humans faced with respect to plants have left their mark on the human mind

How Plants Shape the Mind. Annie E. Wertz. Trends in Cognitive Sciences, June 1 2019,

Abstract: Plants are easy to overlook in modern environments, but were a fundamental part of human life over evolutionary time. Recent work with infants suggests that the adaptive problems humans faced with respect to plants have left their mark on the human mind.

‘Everybody’s doing it’: on the persistence of bad social norms

‘Everybody’s doing it’: on the persistence of bad social norms. David Smerdon, Theo Offerman, Uri Gneezy. Experimental Economics, May 31 2019,

Abstract: We investigate how information about the preferences of others affects the persistence of ‘bad’ social norms. One view is that bad norms thrive even when people are informed of the preferences of others, since the bad norm is an equilibrium of a coordination game. The other view is based on pluralistic ignorance, in which uncertainty about others’ preferences is crucial. In an experiment, we find clear support for the pluralistic ignorance perspective. In addition, the strength of social interactions is important for a bad norm to persist. These findings help in understanding the causes of such bad norms, and in designing interventions to change them.

Keywords: Social norms Pluralistic ignorance Social interactions Equilibrium selection Conformity