Since adoptive parents generally get to choose the gender of an adopted child, if parents prefer boys we would expect to see boys adopted more often. And if girls are unwanted, we should see more girls given up for adoption.
Gender Preference in the United States
Do U.S. parents prefer to have sons over daughters?
Many articles about sex selection take it as a foregone conclusion that U.S. parents would overwhelmingly choose to have boys, if they had a choice. Although this is sadly the case in some parts of the world, in the United States it's a different story. It turns out that there's plenty of good evidence that U.S. parents want daughters just as much as sons.
Evidence that U.S. parents DO NOT prefer sons over daughters:
- Adoption statistics. U.S. parents request girls far more often than boys, even where more boys than girls are waiting to be adopted.
- Abortion statistics. There is no evidence that females are aborted more often than males in the United States. The birth ratio of girls has actually increased slightly since the legalization of abortion.
- Sex Selection statistics. The majority of Americans currently attempting to use sex selection are hoping to conceive a girl.
Evidence that U.S. parents may prefer sons:
- Gallup Poll on gender preference. A Gallup Poll conducted since 1941 shows a preference for sons for a hypothetical only child. The preference for sons is strong among men, but women have a slight preference for daughters.
- "The Demand for Sons" study. Among other things, this widely publicized study claimed that parents of girls were more likely to divorce than parents of boys. The study's results turn out to be very questionable.
In fact, the opposite is true. Parents seeking to adopt request girls far more often than boys, regardless of whether they are seeking to adopt within the U.S., where there are slightly more boys than girls awaiting adoption, or from Russia, where there are more boys and the wait for a girl is much longer, or from China, where nearly all adoptees are girls. This trend was noted as far back as 1916 ("Why do so many people prefer girls!").
U.S. parents also adopt far more girls than boys through international adoption. The trend reflects the large proportion of girls available for adoption from China and other Asian countries. In China, girls are unwanted; but in America, every year thousands of families adopt those discarded daughters into their homes and hearts.
Do U.S. parents adopt girls just because no boys are available? This is certainly true for adoptions from China; but nearly as many adoptees come from Russia (and the former USSR), where more boys are available and the wait for a girl is longer. Yet parents still request a girl more frequently.
Gender of Adoptees from China, 2001
96% Girls, 4% Boys
Gender of Adoptees from Russia, 2001
52% Girls, 48% Boys
Conclusion: Adoption Statistics and Gender Preference
While adoptive parents may prefer girls, it doesn't necessarily mean that all parents have the same preference for their own biological children. However, the trend is so strong and consistent, we can't ignore the simple fact that, when U.S. parents get to choose, they choose girls. Adoption data shows actual choices made by parents, not hypothetical responses to a poll question.
I recently read an anti-abortion article stating that, since U.S. parents prefer boys, girls were aborted disproportionally more often. When I contacted the author, he couldn't substantiate this statement, but assured me that he read it somewhere. What he probably read was that worldwide, far more females than males are aborted -- but there is no evidence that this is true in the U.S. In fact, since the legalization of abortion, the birth ratio of girls has increased relative to boys.
Sex Selective Abortion is Rare in the United States
In the U.S., the gender of an unborn baby is rarely a factor in the decision to have an abortion, because most abortions happen too early in pregnancy to detect the baby's gender.
Only 5% of abortions in this country are even potentially gender related, because only 5% occur when it is likely the mother knows the baby's gender. I hasten to point out that "only 5%" of the 1.3 million abortions annually in the U.S. is still a staggering 65,000 babies, and the loss of each one of those little souls for any reason is a tragedy.
Abortions in the U.S. by 10th Week of Pregnancy
Baby's gender is definitely unknown at this point.
Abortions in the 11th through 12th Week of Pregnancy
Possible, but extremely unlikely, that gender is known.
Abortions in the 13th through 15th Week of Pregnancy
Some will know gender by this point, but not most.
Abortions in the 16th through 20th Week of Pregnancy
Gender is usually determined by ultrasound around 20 weeks.
Abortions after the 20th Week of Pregnancy
Gender is probably known by now if an ultrasound is performed.
The U.S. Center for Disease Control and Prevention tracks and publishes extensive data on abortion, but information about the gender of aborted babies does not seem to be available.
The Birth Ratio of Girls Has Increased Since the Legalization of Abortion
A 1998 report published in the respected Journal of the Americal Medical Association (JAMA) showed that, between 1970 and 1990, the birth ratio of boys to girls in the U.S. declined by .0001 from the normal birth ratio of 106 boys per 100 girls. This sounds like a tiny number, but is considered statistically significant for such a large population. While no one is suggesting that this trend is the result of aborting boys, it certainly seems to rule out any significant sex selective abortion of girls in the U.S.
Conclusion: Abortion Statistics and Gender Preference
Although you may see a statistic that 42% of female fetuses are aborted compared to 25% of male fetuses, this figure is worldwide, and reflects the widespread practice in some East and South Asian countries of aborting many female babies. In the U.S., only a small percentage of abortions happen when it is even likely that the mother knows her unborn baby's gender, and there is no evidence that either gender is aborted more often.
Sex Selection Statistics and Gender Preference
Actual parents seeking to use currently available sex selection techniques are mostly trying to have a girl.
MicroSort Sex Selection
80% of American families who use MicroSort sperm separation want a girl.
The fact that MicroSort is 91% effective for conceiving a girl, compared to only 76% accurate for a boy, is probably a factor in more requests for a girl.
Gender Requested by U.S. Parents Using MicroSort
80% Girls, 20% Boys
Ericsson Method for Gender Selection
Although the Ericsson method claims a higher success rate for boys, Dr. Ericsson reports that more requests are for girls; in some of the 48 licensed Ericsson clinics, the ratio is as high as 2 to 1.
Gender Requested by U.S. Parents Using the Ericsson Method
Twice as many girls as boys
The Gen-Select Kit
The Gen-Select kit claims to be 96% effective in choosing either a boy or a girl. The company says that virtually all U.S. parents purchase the $199 kit for family balancing, hoping for a child of the opposite gender of the children they already have. Girl kits are purchased 8% more often than boy kits.
Gender of Gen-Select Kits Purchased in the U.S.
54% Girls, 46% Boys
Ericsson Sex Selection
The Ericsson method claims to be more effective for selecting a boy: 81% accurate, compared to only 74% for a girl.
Yet Dr. Ronald Ericsson, the inventor and company president, "has noticed a distinct preference in the desire for
girls," and infers that "the era of wanting a first-born
male is gone, not to return."
Message Boards About Sex Selection
In several online forums about sex selection, mothers hoping to choose the gender of their next baby discuss and research methods and share their outcomes. The iVillage Gender Determination group is one of the most active, with over a quarter-million posts. Although the data is anecdotal, it can't be ignored that only a small minority of members are seeking a son, while most are hoping for a daughter. This trend holds regardless of which sex selection method is being considered, whether it is a high-tech method like MicroSort or PGD, or an at-home method like Shettles or O+12.
Although exceptions surely exist, as a rule members of the online forum fit this description:
Maureen's Rough Estimate of Gender Sought by
Mothers Posting on Sex Selection Message Boards
90% Girls, 10% Boys
- Value both genders, and simply want the opportunity to parent both. None are trying to have all boys or all girls.
- Are seeking family balancing, usually after having 2 or more children of the same gender already. Only a few explore sex selection for a second child, and none for a first child.
Gallup Poll and Gender Preference
The Gallup organization first quizzed Americans on whether they preferred a son or a daughter in 1941. The response has remained the same over 50 years: sons are preferred.
The question: "Suppose you could have only one child. Would you prefer it to be a boy or a girl?"
Strong Son Preference Among Men
Data from the 2000 and 2003 poll show that women have a nearly equal preference for a boy or a girl, yet men chose a boy 2.5 times more often.
Gallup Poll and Sex Selection
The Gallup Poll shows responses to a hypothetical question, and may not be a good indicator of how U.S. parents would use sex selection. On the poll, choosing a gender is as easy as checking a box. In real life, sex selection is very expensive, inconvenient, and invasive.
"The Demand for Sons" Study
In 2003, a study titled "The Demand for Sons: Evidence from Divorce, Fertility, and Shotgun Marriage" was published by two economics professors, Gordon Dahl and Enrico Moretti. Dahl and Moretti analyzed the U.S. Census from 1940 to 2000, and detected several subtle trends; each trend, they said, might be accounted for by some other explanation, but taken together showed a pattern of a preference for sons.
Parents of Daughters are More Likely to Divorce (Not!)
The study's most publicized finding, that parents of all-girls are more likely to divorce than parents of all-boys, prompted these headlines:
I guess busy journalists don't have time to actually read a hefty 71-page study, but you'd think they could at least reach the top of page 2:
... a 1% to 7% higher divorce probability ... is strongest in the early years of the data and declines over time, so that by the year 2000, the effect seems to have disappeared.
That's right, the higher divorce probability was only in the past; by the year 2000, parents of girls were no more likely to divorce than parents of boys. Yet when the study was published in 2003, media coverage insisted that a "new study shows daughters cause divorce". I guess an accurate headline would have been too boring: "Fifty Years Ago, Parents of Daughters Were Slightly More Likely to Divorce than Parents of Sons, But Not Any More!"
Here is some of the divorce data from the study.
Dahl and Moretti's interpretation is that fathers prefer sons, and are more likely to stick with a marriage if they have sons rather than daughters. Or, you might say, although fathers may prefer sons, even among fathers with FOUR daughters, 93% of them are no more likely to divorce than fathers with four sons.
U.S. Census, Divorces from 1940 through 2000
How much more likely were parents of only girls to get divorced
than parents of only boys? By family size:
0.9% more likely that parents of 1 girl got divorced than parents of 1 boy
2.3% for 2 girls vs. 2 boys
5.4% for 3 girls vs. 3 boys
7.4% for 4 girls vs. 4 boys
Either way, the chart above is for ALL divorces in the U.S. Census from 1940 through 2000. Take a look at the same trend by Census year:
How much more likely are parents of all girls to divorce than parents of all boys? By family size and Census year.
Chart by Maureen.
Source: Table 3,
"The Demand for Sons"
In 2000, we see that difference in divorce probability between boy/girl parents has become insignificant. Even parents of 3 girls (yellow line) are only 0.57% more likely to divorce than parents of 3 boys. And parents of 2 girls have become slightly less likely to divorce than parents of 2 boys (note the green line dips below zero).
In statistical terms, all of the values reported for 2000 fail the test for statistical significance, because they are less than the standard error. A close look at the rest of the divorce data in the study reveals that most of the values just barely pass the statistical significance test.
Divorced Fathers Are More Likely to Gain Custody of Sons
The study reports that fathers of only boys have an 11% to 22% higher probability of having custody of their children than fathers of only girls. Again, these numbers can be misleading because they include all divorces from 1940 through 2000. However, although we see this trend decreasing over time, it is still noticeable in 2000 that fathers are more likely to have custody of their sons than daughters.
Dahl and Moretti believe this trend illustrates that fathers like boys better, and so try harder to get custody of them. They even go on to theorize that the reason that fathers of boys are now just as likely to divorce as fathers of girls is not because fathers now like daghters just as much, but because fathers are now much more likely to obtain child custody than in the past. In other words, they think fathers in previous decades might have stayed married just to be with their sons; but now, fathers figure that they can go ahead and get divorced and still have a good chance of getting custody of their sons.
U.S. Census, Divorced Fathers in 2000
How much more likely are fathers of only boys to have custody
of their children than fathers of only girls? By family size:
10% more likely that father of 1 boy has custody than father of 1 girl
8% more likely for 2 boys vs. 2 girls
2% more likely for 3 boys vs. 3 girls
U.S. Census, Divorced Fathers in 2000
Actual Percentage of Father Custody by Gender and Family Size
25% of divorced fathers with 1 son have custody
22% of divorced fathers with 1 daughter have custody
23% of divorced fathers with 2 sons have custody
21% of divorced fathers with 2 daughters have custody
21.5% of divorced fathers with 3 sons have custody
21.0% of divorced fathers with 3 daughters have custody
Gender Preference and Marriage, Shotgun Marriage, Remarriage, and Second Divorce
Dahl and Moretti go on to report several findings about gender preference and marriage.
- Marriage: Mothers of girls are more likely to never marry than mothers of sons.
Dahl and Moretti do not report whether this trend has changed over time, but only tell us the aggregate for 1940 through 2000.
U.S. Census, 1940 - 2000
How much more likely is it that a mother of all girls never marries
than a mother of all boys? By number of children:
1% more likely that a mother of 1 girl never marries than a mother of 1 boy
7% more likely for 2 girls vs. 2 boys
4% more likely for 3 girls vs. 3 boys
- Shotgun Marriage: Unmarried pregnant mothers who have an ultrasound are 4.6% more likely to be married by the baby's birth if the baby is a boy.
Data for this finding is based on California birth statistics for 1989-1994. I am curious about the choice of California data, because California has a disproportionately large Asian population (10.9%) compared to the rest of the U.S. (3.6%), and it's well known that the Asian culture has a strong preference for sons. So it seems that the sample would include 7.3% of fathers much more likely to be son-biased than the general U.S. population.
- Remarriage: Divorced mothers of daughters are equally likely to remarry as mothers of sons.
- Second Divorce: Among divorced mothers who remarry, a second divorce is more likely for mothers of only daughters than mothers of only sons.
Data for this finding is available only for 1940 - 1980, so we don't know whether it has increased or decreased to the current day.
U.S. Census, 1940 - 1980
How much more likely is it that a mother of all girls will have
a second divorce than a mother of all boys? By number of children:
3% more likely that a mother of 1 girl divorces again than a mother of 1 boy
5% more likely for 2 girls vs. 2 boys
4% more likely for 3 girls vs. 3 boys
Parents of Girls Are More Likely to Have Another Child
Dahl and Moretti found that parents of only girls were more likely to have another child, presumably hoping for a boy.
Confirming the strong Asian preference for sons, among those with 2 daughters, Asians were much more likely to have a 3rd child.
U.S. Census, 1940 - 2000
How much more likely is it that parents of all girls will have
another child than parents of all boys? By family size:
0% Same odds that parents of 1 girl have another child as parents of 1 boy
2% more likely for 2 girls vs. 2 boys
3% more likely for 3 girls vs. 3 boys
5% more likely for 4 girls vs. 4 boy
As we have seen throughout the study, the trend decreases over time, until in the year 2000, there is a 2% higher probability that parents of 2 girls would have a third child than parents of 2 boys.
U.S. Census, 1940 - 2000
Same question as above, but by race:
2% for Whites
1% for Blacks
17% for Asians
1% for other races
Dahl and Moretti also report that parents have a second child sooner if the first child is a girl. How much sooner? An average of 6.2 days, supposedly the result of what one journalist refers to as "Henry VIII-like eagerness for a male heir". However, medical literature provides other explanations:
U.S. Census, 2000 Only
Percentage of families who have a third child, by gender:
36.5% of parents of 2 boys have a 3rd child
35.8% of parents of 2 girls have a 3rd child
- Boys are more likely than girls to be born prematurely, shortening the average time until the next pregnancy for mothers of boys compared to mothers of girls.
- A mother of a boy is more likely to suffer from recurrent miscarriages in subsequent pregnancies. (Human Reproduction, Oct-2004)
"The Demand for Sons" Conclusion
The findings in this study show miniscule margins that dwindle over time, and are very often based on results that are just barely statistically significant. Media coverage of the study blew the findings out of proportion, and missed the real story altogether: that son bias has steadily and dramatically decreased until the present day. Personally, I find it irresponsible and offensive for parents of daughters to be told that they are more likely to divorce, when in fact this is not the case. And Dahl and Moretti, shame on you for distorting the data for the sake of 15 minutes of celebrity.