Expect problems and eat them for breakfast


A growing body of literature has shown that environmental exposures in the period around conception can affect the sex ratio at birth through selective attrition that favors the survival of female conceptuses. Glucose availability is considered a key indicator of the fetal environment, and its absence as a result of meal skipping may inhibit male survival.

We hypothesize that breakfast skipping during pregnancy may lead to a reduction in the fraction of male births. Using time use data from the United States we show that women with commute times of 90 minutes or longer are 20 percentage points more likely to skip breakfast. Using U.S. census data we show that women with commute times of 90 minutes or longer are 1.2 percentage points less likely to have a male child under the age of 2. Under some assumptions, this implies that routinely skipping breakfast around the time of conception leads to a 6 percentage point reduction in the probability of a male child. Skipping breakfast during pregnancy may therefore constitute a poor environment for fetal health more generally.

{ Biodemography and Social Biology | Continue reading }

photo { Ralph Eugene Meatyard, Occasion for Diriment, 1962 }

related { Determinants of online sperm donor success: How women choose }

and go we know not where


This article examines associations between the Great Recession and 4 aspects of 9-year olds’ behavior - aggression (externalizing), anxiety/depression (internalizing), alcohol and drug use, and vandalism - using the Fragile Families and Child Wellbeing Study, a longitudinal birth cohort drawn from 20 U.S. cities (21%, White, 50% Black, 26% Hispanic, and 3% other race/ethnicity).

The study was in the field for the 9-year follow-up right before and during the Great Recession (2007-2010; N = 3,311). Interview dates (month) were linked to the national Consumer Sentiment Index (CSI), calculated from a national probability sample drawn monthly to assess consumer confidence and uncertainty about the economy, as well as to data on local unemployment rates.

[W]e find that greater uncertainty as measured by the CSI was associated with higher rates of all 4 behavior problems for boys (in both maternal and child reports). Such associations were not found for girls.

{ Developmental Psychology | Continue reading }

photo { Yosuke Yajima }

It’s a great thing when you realize you still have the ability to surprise yourself


A new study from Duke University finds that adolescents ages 10 to 16 can be more analytical in their economic choices than many slightly older young adults. […]

Scott Huettel, a professor of psychology and neuroscience at Duke: “The new results point to the idea that we should not think of adolescents as being irrational. What’s different about them is they don’t use simple rules as effectively.”

Such simple rules are the mental shortcuts people take in decision-making—often to their benefit—as they age and gain more experience. Most adults apply the “don’t drink and drive” rule, for example, to avoid getting in a car with someone who’s been drinking. In contrast, teens may more carefully weigh this decision.

“Adolescents are going to be more likely to use cost-benefit analysis than the (simple rules) that adults use.” […]

Other research has shown that adolescents aren’t necessarily more risk-seeking but that they are more sensitive to good outcomes compared with adults.

{ Science Beta | Continue reading }

photo { Vasantha Yogananthan }

Aristotle concluded more than 2,300 years ago that ‘the young are heated by Nature as drunken men by wine.’


Although parents often try not to favor one child, we examine whether specific environmental factors might bias parents to favor children of one sex over the other. […] a series of experiments show that poor economic conditions favor resource allocations to daughters over sons.

{ Journal of Consumer Research | PDF }

Adolescence, from Latin adolescere, meaning “to grow up”


Participants were 152 students (88 women, 64 men; average age 19.7) at a “mid-sized university in the northeastern US.” […]

Texting during class was not acceptable, but 84.7% had done this. Texting in the shower is unacceptable and 34% have done this. Texting during the Pledge of Allegiance is unacceptable and 11.3% have done it. Texting while having sex is unacceptable and 7.4% have done it. Talking to a friend and texting another at the same time is unacceptable and between 79% and 84% have done it. Texting one person in whom you are romantically interested while on a date with someone else is unacceptable and 21.5% have done it. Breaking up by text is unacceptable and 26% have done it. Sending text messages while at a funeral is unacceptable and 10.1% have done it. Texting during a job interview is unacceptable and 2.7% have done it. Fighting with some via text is unacceptable and 66% have done it. Sexting is unacceptable and 42% have done it.

{ The Jury Room | Continue reading }

photo { Danny Lyon, New Year’s Eve on the subway, 1966 }

unrelated { Kids can’t tell the difference between journalism and advertising }

‘Sooner or later, each desire must encounter its lassitude: its truth…’ –Cioran


Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood.

Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in children. We compared two perspectives: social learning theory (positing that narcissism is cultivated by parental overvaluation) and psychoanalytic theory (positing that narcissism is cultivated by lack of parental warmth).

We timed the study in late childhood (ages 7–12), when individual differences in narcissism first emerge.

In four 6-mo waves, 565 children and their parents reported child narcissism, child self-esteem, parental overvaluation, and parental warmth. Four-wave cross-lagged panel models were conducted.

Results support social learning theory and contradict psychoanalytic theory: Narcissism was predicted by parental overvaluation, not by lack of parental warmth. Thus, children seem to acquire narcissism, in part, by internalizing parents’ inflated views of them (e.g., “I am superior to others” and “I am entitled to privileges”).

Attesting to the specificity of this finding, self-esteem was predicted by parental warmth, not by parental overvaluation.

{ PNAS | Continue reading }

Now, baby, Cissy Caffrey said. Say out big, big. I want a drink of water. And baby prattled after her: A jink a jink a jawbo.


Recent studies have shown that women are more sensitive than men to subtle cuteness differences in infant faces. It has been suggested that raised levels in estradiol and progesterone may be responsible for this advantage. […]

Thirty-six women were tested once during ovulation and once during the luteal phase of their menstrual cycle. In a two alternative forced-choice experiment, participants chose the baby which they thought was cuter (Task 1), younger (Task 2), or the baby that they would prefer to babysit (Task 3). […]

During ovulation, women were more likely to choose the cuter baby than during the luteal phase, in all three tasks. These results suggest that cuteness discrimination may be driven by cyclic hormonal shifts.

{ Hormones and Behavior | Continue reading }

art { Henri Chopin, La crevette amoureuse, 1967-1975 }

We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light.


Sleep is undoubtedly important not only for how well we think, feel and behave in our daily lives but also for longer-term health. In childhood, the quantity and quality of night-time and 24 hour sleep have consistently been identified as predictor of health. For example, night sleep predicts weight status. These findings have led to the hypothesis that increasing quantity of sleep through promoting daytime sleep would benefit child health. We sought to look for evidence on the independent effects of daytime sleep on child health, learning and behavior to assess whether this hypothesis was supported. […]

The evidence suggests that beyond the age of 2 years when cessation of napping becomes more common, daytime sleep is associated with shorter and more disrupted night sleep. Those studies examining direction of effect all report that daytime sleep is not a response to poor night sleep but rather precedes poor night sleep.

Evidence relating to cognitive functioning, accidents, weight status and behavior were less conclusive.

{ Medical Research | Continue reading }

quote { Statements that Plato never made }

‘L’enfant rit quand il tue.’ –Victor Hugo


{ a device to aid women in giving birth — the woman is strapped onto a circular table, and the table is then rotated at high speed | Apparatus for facilitating the birth of a child by centrifugal force | via Improbable }

And shall not Babel be with Lebab?


Sex in reptiles and fish is determined after conception, during embryogenesis, according to ambient environmental temperature. In contrast, in mammals and birds, sex is determined at conception.

In mammals, male births invariably occur slightly in excess […] with approximately 3% more males born than females. The reason for this discrepancy is uncertain as testicles produce equal numbers of X-bearing and Y-bearing spermatozoa. […]

We have shown that M/F varies in geographical space, exhibiting a latitude gradient, and that this gradient is different in Europe and North America, with more males born towards the south of Europe, compared with the North American continent where more males are born towards the north of the continent.

Other studies have also shown that M/F may vary with time. Several authors have shown that M/F has declined over the second half of the 20th century in various industrialised countries. These include Denmark, the United Kingdom, the Netherlands, Germany, Canada, the United States of America, and Finland. In contrast, M/F has been noted to have risen in Ireland over the same period. A non-significant rise in M/F has also been noted in Australia and Japan.

{ J Epidemiol Community Health | Continue reading }

A wide variety of factors have been shown to influence the male to female ratio at birth, which invariably displays a male excess. […] It will be shown that stress, including stress related to political events, influences this ratio.

{ Early Human Development | Continue reading }

related { Study: ”Woman on top” is the most dangerous sex position, responsible for half of all penile fractures }

‘I don’t really think, I just walk.’ –Paris Hilton


Carrying a backpack may negatively affect the posture of schoolchildren and contribute to spinal pain.

The aim of this study was to examine changes in the body posture parameters defining asymmetry of the trunk and lateral flexion of the spine in children while carrying a backpack weighing 10% of a child’s weight. […]

Results show that carrying a backpack in an asymmetrical manner negatively affects spine, even if the backpack weight constitutes 10% of the child’s weight.

{ SAGE | Continue reading }

illustration { Rockin Jellybean }

Everything interesting takes place in the dark


Recent theoretical developments in evolutionary psychology suggest that more intelligent individuals may be more likely to prefer to remain childless than less intelligent individuals.

Analyses of the National Child Development Study show that more intelligent men and women express preference to remain childless early in their reproductive careers, but only more intelligent women (not more intelligent men) are more likely to remain childless by the end of their reproductive careers. […]

Because women have a greater impact on the average intelligence of future generations, the dysgenic fertility among women is predicted to lead to a decline in the average intelligence of the population in advanced industrial nations.

{ Social Science Research | PDF }

photo { Richard Kern }