“Pornography ‘addiction’ does not look like other addictions – full stop,” says Dr Nicole Prause, a neuroscientist formerly at UCLA but now founder of sexual health start-up Liberos LLC.

According to Prause, so-called porn and sex ‘addictions’ look similar to other addictions, such as gambling and drugs, in that they activate reward circuitry. But they do not look like them in other important ways.

For one, people with ‘problematic porn use’ report they have a lack of control – but when tested for it, that appears not to be the case, she says. But the main difference is that with addiction to drugs and gambling, addicts experience ‘sensitisation’: they become more sensitive to the cues of their addiction, and her research indicates porn decreases sensitivity.

Meanwhile, Voon says there is good evidence that excessive consumption of porn can lead to ‘habituation’: the desire for novel stimuli. This means regular viewers crave more hardcore scenes the more they watch. This is a trend that many men have reported anecdotally and sought treatment for.

“Although I wouldn’t yet call it an addiction, it certainly is a compulsive sexual behaviour, and there is no question that for some people excessive and compulsive use has led to difficulties in relationships, lost jobs due to watching porn at work and even suicide attempts,” Voon says.

In 2015, she and her team published a study suggesting that online porn in particular can allow sex addicts to chase after more novel and hardcore images, onwards and onwards down the rabbit hole of the internet, enabling and worsening their addiction.

“For some people this did escalate into watching more hardcore forms.” There is agreement, however, that much more work needs to be done. “We don’t know a lot about these disorders, but there is no question that a lot of people are suffering,” says Voon.

“There is a lot of shame, so a lot of people don’t seek help. The more we can recognise this as a disorder, the more we can decrease the shame surrounding this, and increase both the likelihood of people coming for treatment and our chances of helping them.”

Read more about pornography, sex and the brain:

• UK porn block: what is it and will it work?
• Is addiction on the rise?

What’s the harm of porn?

Modern studies of ‘the brain on porn’ are undoubtedly headline-grabbing and provocative. But this is not the first time that scientists have scrutinised pornography and the ways it could impact the human condition.

In the 1970s, there was widespread concern that porn was contributing to sexist attitudes, ultimately leading to a rise in violent assaults. The fears were understandable. But have scientific studies been able to turn up any evidence?

“The academic aim was to take radical feminist ideas and put them into testable hypotheses,” says psychologist Prof Neil Malamuth of the University of California Los Angeles. “I wanted to find the characteristics of men who were more likely to be aggressive towards women – porn was just one factor among many.”

Decades of research, he says, have shown that for men, excessive viewing of pornography is consistently associated with sexist attitudes, coercive acts, aggressive behaviour and other dangerous outcomes.

A meta-analysis – a study of studies – published by Malamuth in 2009 found that hundreds of papers from the 1980s to 2008 were fairly consistent in linking high rates of porn viewing with violent ideas and behaviour. But here’s the caveat: not all men respond to porn in the same way.

For most men, consuming porn will not cause them to view women differently. But in those who already are predisposed to hold sexist views or to behave in an aggressive fashion, porn can exacerbate pre-existing and dangerous propensities. In this way, it’s just like any other drug.

Alcohol, for example, is in many ways comparable to porn because it is ubiquitous, socially acceptable and legal.

“For some people, alcohol can truly ruin their lives,” explains Malamuth. “But for others it can be mildly positive, such as providing stress relief or enhancing their sex lives. It depends on the cultural context – and the individual.”

Is porn good for you?

But can watching porn actually be beneficial to certain people? Prause thinks so. “There is as much of a case to be made for the benefits as well as the harms,” she says. For example, porn can introduce viewers to new activities that can ‘spice things up’ in the bedroom.

“There is good evidence for mimicry, so we have good evidence that sometimes viewing porn can increase people’s tendency to perform oral sex. Erotica can have positive and negative effects, it’s about identifying for whom, and when.”

The field is riddled with misconceptions and biases that are not supported by the data, she says.

Despite concerns that porn can decrease libido and lead to impotence due to ‘tolerance’ and ‘desensitisation’, research published by Prause in the journal Sexual Medicine in 2015 shows these worries to be unfounded.

Similarly, it is accepted as gospel truth that rates of pornography viewing have increased dramatically with the rise of the internet, allowing for instant access to a huge diversity of images at home. But in fact, Prause says, statistics indicate that the number of people viewing pornography overall hasn’t changed since the introduction of the VCR.

Perhaps more surprisingly, recent research has gone against studies from the 1980s and 1990s in saying that increased access to pornography can often lead to decreases in rates of sexual assault. These findings emerged after changes to the laws in parts of Canada, Croatia, Denmark, Germany, Finland, Hong Kong, Shanghai, Sweden and the US allowed easier access to pornographic imagery.

Although Prause disagrees with the conclusions of other researchers such as Malamuth, she does agree – along with just about every other sex researcher – that porn can be dangerous for some men because it can reinforce pre-existing misogynistic beliefs and myths.

“The most well-replicated and concerning harm is reinforcing rape myths in men who already believe them,” says Prause. Such that if you take a woman on a date, she owes you sex. Or that women secretly want to be coerced into sex.

“People who already hold these ideas and who start to watch violent erotica will start to believe those myths more strongly over time, and that is definitely associated with sexual assault,” says Prause. Run-of-the-mill ‘vanilla’ porn does not tend to reinforce dangerous attitudes, she says, but violent porn certainly can.

On the plus side, Prause says that researchers could potentially use porn in a lab setting to treat those with violent, abusive inclinations. “If we can reinforce that these films are fantasy, not reality, it is possible to actually reduce the harms from erotica,” she says.

Porn propaganda

A big problem with researching porn, says psychologist Dr Taylor Kohut of the University of Western Ontario, is the way that it is portrayed in the media.

“Magazines like to sell a tighter, neater story than actually exists, and this can be a huge problem because researchers often get their ideas about what should be studied by what they see in the news. There is a relationship between the two, and it is reciprocal and symbiotic,” he says. “It’s not always negative, but it is significant.”

Kohut meticulously documented ‘asserted harms’ in media reports on porn, ranging from sexual assault and rape myths to communism and organised crime, in a 2015 paper frankly titled How The Popular Media Rushes To Judgment About Pornography And Relationships While Research Lags Behind.

He found the five main ideas on porn you see in the media are: porn is addictive, porn is good for relationships, using porn constitutes adultery, using porn makes your partner feel inadequate, and porn changes your expectations about sexual behaviour. This represents a wider spread of opinions than current research perhaps reflects.

“My biggest concern regarding the scientific study of porn is that a noticeable subset of researchers come at these issues with a focus on harm in their minds. They try to establish ways to confirm that porn is causing whatever harm they already believe exists,” he says. “The field needs more people who are willing to look at the data and leave aside their politics and their issues.”

About our experts

Prof Valerie Voon is a neuroscientist based at the University of Cambridge who studies impulsivity, compulsion and addiction. Her research focuses on understanding the mechanisms underlying human self-control and compulsivity relevant to addictions and compulsive disorder. 

Prof Neil Malamuth is an interdisciplinary social scientist who studies violence and conflict based at UCLA. His research looks at identifying the characteristics of men who commit sexual aggression against women. 

Dr Taylor Kohut is a psychologist at the University of Western Ontario, where he studies human sexuality and the positive effects of pornography. His research has been published in PloS One and The Journal Of Sex Research.

Dr Nicole Prause is an American neuroscientist who researches human sexual behaviour and addiction. In 2015, she founded sexual biotechnology company Liberos LLC after studying at the Sexual Psychophysiology and Affective Neuroscience Laboratory for 10 years. 

Read more:

• Do men need sex more than women?
• Do any other animals have sex for pleasure?

• This article first appeared in issue 293 of BBC Science Focus – find out how to subscribe here

---