Kim So-young's IQ Revealed: What Does It Mean for the Motel Murder Case?

[iNews24 reporter Kim Da-woon] The defendant in the Gangbuk motel serial murders, Kim So-young, is reported to have an intelligence quotient (IQ) below the population average.

On the 26th, criminal psychologist Professor Lee Soo-jung of Kyonggi University appeared on the Chosun Ilbo YouTube program Dong-sang-i-mong and analyzed the Kim So-young case.

Before authorities released the mugshot, observers noted a marked contrast between the personal photos Kim So-young posted on social media and her official mugshot, which drew public attention.

Professor Lee said the stark difference between the two images could reflect another psychological characteristic of Kim So-young.

She explained that someone with a coherent sense of identity typically presents themselves as they are. In contrast, Kim So-young appears unable to present an authentic self.

Professor Lee also said experts assessed Kim So-young's IQ as below 80.

According to Professor Lee, the average IQ is 100, and an IQ below 70 corresponds to a Level 3 intellectual disability.

Kim So-young is reported to have scored above 70 but below 80, placing her in the lowest 10 percent and indicating significantly low intellectual functioning.

Professor Lee said that when intellectual functioning is markedly low, it is generally very difficult for someone to execute meticulous, premeditated actions. She added that if the motel murders were planned, that would suggest they were orchestrated by someone with higher intellectual capacity. The fact there were two victims, she noted, likely matched the police's initial impression.

Kim So-young has been diagnosed with antisocial psychopathy, but Professor Lee said severely low intelligence and antisocial personality traits can coexist; they are not mutually exclusive.

However, she cautioned that clinicians often advise against diagnosing psychopathy in individuals who have schizophrenia or markedly low intelligence. Determining which factor is dominant is difficult, and she believes both factors influenced Kim So-young simultaneously.

She added that the personality problems likely originated during early development, when core personality traits form, and that those problems may have caused developmental delays.

In short, underdeveloped cognitive control may have impaired her ability to restrain impulses, which could have contributed to these crimes.