David Baxter PhD
Late Founder
'Tough broads' tend to give birth to more boys
Wednesday, March 08, 2006
by Tom Spears, The Ottawa Citizen
A psychologist claims an online test can identify the likely mothers of males, Tom Spears reports
A New Zealand psychologist is offering tests that claim to predict whether women will likely conceive a girl or a boy, based on her theory that pushy, "tough-broad" mothers have more baby boys.
Tough guys, adds psychologist Valerie Grant, are more likely to father girls. But her efforts are geared to expectant mothers.
For about $8, women who have just conceived, or who plan to conceive soon, can take the test on the Internet. After typing in a credit card number, the woman sees a list of more than 60 feelings. She's asked to pick the ones she experiences "quite often." These include feeling hopeful, vigorous, shy, sad, protected, relaxed, feeble, admired, domineering, lucky, powerful, self-satisfied, concentrating, controlling, triumphant, happy, frustrated, crushed, and alone with responsibility.
So what does this have to do with a baby's sex?
Since 1966, Ms. Grant has been studying the puzzle of human sex ratios.
For every 100 baby girls, 106 baby boys are born -- even though sperm cells are exactly half equipped to produce girls (by transmitting an X chromosome) and half rigged for boys (a Y chromosome.)
Somehow, the math doesn't add up.
Ms. Grant believes that a baby's sex is determined by other factors as well, and that tough-minded, dominant women who have high levels of testosterone are more likely to produce baby boys.
"Women have only one-tenth the amount of testosterone that men do. But even these tiny amounts may somehow influence whether a woman conceives a boy or a girl," she writes in a summary of her theory. "If the woman has more than average testosterone, the hormonal environment may make it easier to conceive a male."
She acknowledges she doesn't know why a women's testosterone level affects the baby. Other factors come into play too, she says. For instance, male astronauts, soldiers, timber mill workers and deep-sea divers tend to have more daughters than sons. No one knows why.
Ms. Grant hasn't checked to see what babies are actually born to women who take the test.
Ms. Grant, who teaches at the Auckland School of Medicine, has also published a series of papers on her work, such as "Maternal dominance and the conception of sons" in the British Journal of Medical Psychology, in 1994.
The test is said to work best if a woman takes it around the time of conception, give or take a month. The test is at www.sexratio.com.
The trouble is, the whole dominant-mother theory isn't widely accepted, says Dr. Roger Pierson, a fertility expert and director of reproductive biology at the University of Saskatchewan.
"That theory has been around for about 30 years," he said. But he said much of it is based on lab or farm animals, not humans. "There's a whole host of things going on in utero" that probably affect the baby's sex, and it just isn't possible to test them without risking harm to the baby, he said.
And the Internet test?
"I think that shows outstanding business sense," he said. "I am going to have to get a job like that."
"The reaction of the scientific community is mixed, if not negative," Ms. Grant wrote in an e-mail response to questions. "I find this hard to understand in the community of evolutionary psychologists (e.g. the Human Behavior and Evolution Society). At my university however, in the last two years, several people have begun to take the work seriously. I recently received some funding so we can try out the actual mechanism, using the cow as a model."
Wednesday, March 08, 2006
by Tom Spears, The Ottawa Citizen
A psychologist claims an online test can identify the likely mothers of males, Tom Spears reports
A New Zealand psychologist is offering tests that claim to predict whether women will likely conceive a girl or a boy, based on her theory that pushy, "tough-broad" mothers have more baby boys.
Tough guys, adds psychologist Valerie Grant, are more likely to father girls. But her efforts are geared to expectant mothers.
For about $8, women who have just conceived, or who plan to conceive soon, can take the test on the Internet. After typing in a credit card number, the woman sees a list of more than 60 feelings. She's asked to pick the ones she experiences "quite often." These include feeling hopeful, vigorous, shy, sad, protected, relaxed, feeble, admired, domineering, lucky, powerful, self-satisfied, concentrating, controlling, triumphant, happy, frustrated, crushed, and alone with responsibility.
So what does this have to do with a baby's sex?
Since 1966, Ms. Grant has been studying the puzzle of human sex ratios.
For every 100 baby girls, 106 baby boys are born -- even though sperm cells are exactly half equipped to produce girls (by transmitting an X chromosome) and half rigged for boys (a Y chromosome.)
Somehow, the math doesn't add up.
Ms. Grant believes that a baby's sex is determined by other factors as well, and that tough-minded, dominant women who have high levels of testosterone are more likely to produce baby boys.
"Women have only one-tenth the amount of testosterone that men do. But even these tiny amounts may somehow influence whether a woman conceives a boy or a girl," she writes in a summary of her theory. "If the woman has more than average testosterone, the hormonal environment may make it easier to conceive a male."
She acknowledges she doesn't know why a women's testosterone level affects the baby. Other factors come into play too, she says. For instance, male astronauts, soldiers, timber mill workers and deep-sea divers tend to have more daughters than sons. No one knows why.
Ms. Grant hasn't checked to see what babies are actually born to women who take the test.
Ms. Grant, who teaches at the Auckland School of Medicine, has also published a series of papers on her work, such as "Maternal dominance and the conception of sons" in the British Journal of Medical Psychology, in 1994.
The test is said to work best if a woman takes it around the time of conception, give or take a month. The test is at www.sexratio.com.
The trouble is, the whole dominant-mother theory isn't widely accepted, says Dr. Roger Pierson, a fertility expert and director of reproductive biology at the University of Saskatchewan.
"That theory has been around for about 30 years," he said. But he said much of it is based on lab or farm animals, not humans. "There's a whole host of things going on in utero" that probably affect the baby's sex, and it just isn't possible to test them without risking harm to the baby, he said.
And the Internet test?
"I think that shows outstanding business sense," he said. "I am going to have to get a job like that."
"The reaction of the scientific community is mixed, if not negative," Ms. Grant wrote in an e-mail response to questions. "I find this hard to understand in the community of evolutionary psychologists (e.g. the Human Behavior and Evolution Society). At my university however, in the last two years, several people have begun to take the work seriously. I recently received some funding so we can try out the actual mechanism, using the cow as a model."
