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Harvey and Georgina Weinstein attend the 2017 Vanity Fair Oscar Party hosted by Graydon.
Hollywood is in a tailspin over how Harvey Weinstein concealed sexually abusive behavior from friends, colleagues, and perhaps an entire industry for decades. But while the investigation into Weinstein continues, recent research offers clues into why so many stars are prone to exploiting others.

London - The Harvey Weinstein sexual assault scandal shows no sign of winding down. Just the opposite: police in the United Kingdom are now investigating several allegations involving the Oscar-winning film producer. While Weinstein has "unequivocally denied" allegations of non-consensual sex, and no arrests have been made, more than two dozen women - including the actors Angelina Jolie, Gwyneth Paltrow, and Rose McGowan - have publicly accused him of harassment. The allegations stretch over nearly three decades.

Hollywood is struggling to explain how one of its most visible figures could have gotten away with such behavior for so long. Woody Allen offered an important clue. Despite working with Weinstein on several films, he claims that no one ever brought allegations of abuse to his attention.

"And they wouldn't, because you are not interested in it," Allen told the BBC. "You are interested in making your movie." Others who worked with Weinstein over the years have made similar statements.

Is this the Hollywood equivalent of a police officer's "blue wall of silence," or is there something more clinical at work?

One possible answer may be found in the results of recent psychological research. According to scientists in the United States and Israel, there are certain personality traits - the "dark triad" of narcissism, psychopathy, and Machiavellianism - that are more commonly associated with sexually abusive behavior.

One intriguing finding from this research, published in 2016 in the journal Personality and Individual Differences, is that personality traits associated with a proclivity for harassment may be "specialized psychological adaptations" that allow individuals to exploit "niches" in society. In other words, some sexual predators may seek careers in particular industries that allow them to exploit others.

The researchers also found that the disposition that makes someone successful may also comprise the personality traits that explain their tendency to exploit. The traits needed to win Academy Awards, for example, may be similar to the traits of an individual who pursues a large number of sexual partners and relationships requiring little commitment.

Taken a step further, the research suggests that we should not be surprised to find a similar parallel in many others corners of society. It is not just in Hollywood where the traits that make someone a star could make the same person an abuser.

The "dark triad" study was published long before the allegations against Weinstein came to light, but it remains the most comprehensive investigation into the personalities of sexual harassers. The researchers - based at Oakland University and the University of Georgia in the US, and Sapir Academic College in Israel - surveyed more than 2,500 Israeli men and women. Subjects prone to exploiting others demonstrated a number of characteristics, including callousness, disagreeableness, deceitfulness, egocentrism, lack of honesty or humility, and an excessive interest in one's personal talents and goals.

This last trait - also known as narcissism - is a key component of the dark triad. Narcissists tend to be convinced of their own magnificence, and believe that other people should be flattered to be in their company - even if that involves unwanted sexual advances.

Machiavellians, meanwhile, believe that the best way to interact with others is to tell them what they want to hear. Their manipulative default can lead to a pattern of continually deceiving colleagues and friends, which may explain why a Machiavellian personality would engage in sexual harassment or pursue short-term sexual encounters. They simply believe they are too cunning to get caught.

When abusers are unmasked, they often seek to deflect blame. Claiming to be suffering from a disorder such as "sexual addiction," or checking into a rehabilitation clinic for "treatment," as Weinstein has reportedly done, fits with a classic Machiavellian response.

If the allegations pan out, Weinstein would be an extreme example of a "dark triad" abuser. But this combination of character traits is not all that rare. In fact, powerful predators might be lurking around the nearest water cooler right now. According to a 1994 survey of federal employees in the US, cited in the "dark triad" study, 44% of female workers, and 19% of male workers, reported being sexually harassed on the job within the two previous years.

And, as the authors of the 2016 study remind us, sexual harassment is not always about trying to secure sex. Rather, psychological drives - including the need to boost one's sense of self-esteem, attractiveness, or masculinity - may be driving predators' abuse of power in dominating or degrading others.

What may be particularly relevant to the Weinstein case, whatever the outcome, is that Hollywood is itself a bubble of narcissistic power. Psychologists could argue that this feature explains the blindness some have demonstrated toward the alleged depraved behavior of one of their colleagues.

Sexual harassment is the immediate focus of the Weinstein case, as it should be, given the severity of the alleged crimes and the distress caused to the victims. But for psychologists seeking to understand the apparent nexus of success and abuse, Weinstein's apparent downfall is just the tip of an analytic iceberg.

Raj Persaud is a psychiatrists based in London, and co-author of the forthcoming book The Streetwise Person's Guide To Mental Health Care.