Other researchers say neonaticides can result from psychosis, triggered by the changing hormones at childbirth, and even during pregnancy.
Susan Hickman, a San Diego psychologist who specializes in pregnancy-related depression, said women who kill their newborns have likely experienced an untreated postpartum disorder in a previous pregnancy or delivery.
In denying their pregnancies, Hickman said, the women become "disassociated from reality," moving in what many will describe as a dreamlike state.
Anderson has described moving in a similar blur during several of her pregnancies, including her last. But psychiatrists who examined her are divided about whether or not she was insane at the time of her delivery.
"I did not acknowledge my pregnancy, per se," Anderson said. "I was an alcoholic. I had very little contact with my family. I have been depressed all of my life."
Anderson delivered her first child at 16, placing the baby up for adoption and finishing high school. She eventually held various jobs, including her last as a credit manager.
In 1980 she gave birth to a son, who now lives with his father. After that pregnancy, Anderson said, she started drinking heavily.
She delivered a third child in 1991 at her home in Fullerton. Her boyfriend took her to the hospital, and the child was placed for adoption.
She said she concealed her following pregnancies.
"If no one confronted me with it, I didn't have to deal with it," she said.
In 1992, Anderson was living with friends when she gave birth to a girl, alone in her bedroom. Her roommate discovered the newborn, not yet cleaned following her birth, when Anderson left for work. Paramedics cleared the newborn's lungs and gave her oxygen. The child was eventually adopted.
Police initially arrested Anderson for felony child endangerment in the case. But prosecutors declined to file charges because of insufficient evidence.
Then in 1995, Anderson was pregnant again. She had just lost her job and was living in her car.
Anderson said she denied she was pregnant until shortly before her delivery, when her mother confronted her and drove her to the social services department to arrange for medical care.
Still, Anderson said, she was in a state of denial. As her mother and stepfather slept upstairs one night, she delivered her last baby, by herself, over a toilet. She wrapped the child in towels and set him on her bed, court documents show.
Anderson told police she heard the newborn take a few raspy breaths immediately after the delivery, then believed he was dead. An autopsy was unable to determine how long the child had lived.
The next day, she placed the baby in a box in her car and drove around on some errands, court documents show. She returned home that evening and faced questions from her mother, who had found a bag of blood-soaked clothing in a closet. Anderson denied she had given birth, and went to bed, according to court documents.
Her mother, suspecting her daughter had been drinking, searched Anderson's car for alcohol. She discovered the newborn's body instead.
Several months after her arrest, Anderson's lawyer saw a news report about the Beale case and raised the issue of whether Anderson had suffered a pregnancy-related disorder.
"Somehow in my mind, before I knew about the pregnancy depression, I knew there was some explanation, I just didn't know what it was," Deputy Public Defender Vicki Carter Briles said. "After I learned more about the disorder, I realized she wasn't a bad person, she just wasn't capable of responding appropriately."
Briles will call on Margaret Spinelli, an assistant clinical professor of psychiatry at Columbia University, who was consulted in the Beale case and examined Anderson, concluding that she was in a disassociated state that rendered her "incapable of knowing or understanding if her act was right or wrong."
Prosecutors argue that Anderson should have known she was putting her child at grave risk, given the earlier child abandonment, and will use the testimony of other psychiatrists to bolster their contention that Anderson was far from insane. They will argue that she is guilty of second-degree murder, based on the theory that her inaction following the delivery demonstrated "conscious disregard" for her child's safety.
Prosecuting Dist. Atty. Paer said medical and psychiatric evidence "doesn't even come close" to showing Anderson was insane at the time of the delivery.
Anderson faces a minimum of 15 years to life in prison if she is convicted. The verdict will be decided by Superior Court Judge Anthony J. Rackauckas Jr. rather than a jury.