At 40, Franz Kafka (1883-1924), who never married and had no children, was walking through a park one day in Berlin when he met a girl who was crying because she had lost her favourite doll. She and Kafka searched for the doll unsuccessfully. Kafka told her to meet him there the next day and they would come back to look for her.

The next day, when they had not yet found the doll, Kafka gave the girl a letter “written” by the doll saying “please don’t cry. I took a trip to see the world. I will write to you about my adventures.” Thus began a story which continued until the end of Kafka’s life.

During their meetings, Kafka read the letters of the doll carefully written with adventures and conversations that the girl found adorable. Finally, Kafka brought back the doll (he bought one) that had returned to Berlin.

“It doesn’t look like my doll at all,” said the girl. Kafka handed her another letter in which the doll wrote: “my travels have changed me.” The little girl hugged the new doll and brought the doll with her to her happy home. A year later Kafka died. Many years later, the now-adult girl found a letter inside the doll. In the tiny letter signed by Kafka it was written: “Everything you love will probably be lost, but in the end, love will return in another way.”

{ Avi | a true anecdote, unproven }

{ Facebook Is Building An Instagram For Kids Under The Age Of 13 }

art { Installation views of Jake or Dinos Chapman, White Cube, 2011 }

Do women need to have children in order to be fulfilled? […] motherhood status did not explain differences in self-reported life satisfaction, and mothers reported only slightly greater happiness than women who were not mothers.

{ Social Psychological and Personality Science | Continue reading }

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Most people in industrialized societies grow up in core (parents only) families with few if any siblings. Based on an evolutionary perspective, it may be argued that this environment reflects a mismatch, in that the tribal setting offered a larger number of close affiliates. The present project examined whether this mismatch may have a negative impact on mental health. […]

The number of household members correlated with scores on good mental health at all ages tested (3, 5 and 8 years). […] Living with a single mother did not make any difference compared to two parents. Girls were slightly more responsive to the presence of siblings than boys. Household pets did not have any appreciable impact.

{ BMC Psychology | Continue reading }

“you only have 100k because of ur url.”

“uh no i had 93k before i got this url so excuse u.”

{ New Republic | Continue reading }

art { Ellsworth Kelly, Diagonal lines, 1951 | James Marshall, Untitled 7, 2015 }

Marijuana is one of the most commonly used drugs in the United States, and use during adolescence — when the brain is still developing — has been proposed as a cause of poorer neurocognitive outcome. Nonetheless, research on this topic is scarce and often shows conflicting results, with some studies showing detrimental effects of marijuana use on cognitive functioning and others showing no significant long-term effects.

The purpose of the present study was to examine the associations of marijuana use with changes in intellectual performance in two longitudinal studies of adolescent twins (n = 789 and n = 2,277). We used a quasiexperimental approach to adjust for participants’ family background characteristics and genetic propensities, helping us to assess the causal nature of any potential associations. Standardized measures of intelligence were administered at ages 9–12 y, before marijuana involvement, and again at ages 17–20 y. Marijuana use was self-reported at the time of each cognitive assessment as well as during the intervening period.

Marijuana users had lower test scores relative to nonusers and showed a significant decline in crystallized intelligence between preadolescence and late adolescence. However, there was no evidence of a dose–response relationship between frequency of use and intelligence quotient (IQ) change. Furthermore, marijuana-using twins failed to show significantly greater IQ decline relative to their abstinent siblings.

Evidence from these two samples suggests that observed declines in measured IQ may not be a direct result of marijuana exposure but rather attributable to familial factors that underlie both marijuana initiation and low intellectual attainment.

{ Proceedings of the National Academy of Sciences }

photo { Julia Margaret Cameron, Paul and Virginia, 1864 }

Roughly a quarter of the world’s people—some 1.8 billion—have turned 15 but not yet reached 30. In many ways, they are the luckiest group of young adults ever to have existed. They are richer than any previous generation, and live in a world without smallpox or Mao Zedong. They are the best-educated generation ever—Haitians today spend longer in school than Italians did in 1960. Thanks to all that extra learning and to better nutrition, they are also more intelligent than their elders. If they are female or gay, they enjoy greater freedom in more countries than their predecessors would have thought possible. And they can look forward to improvements in technology that will, say, enable many of them to live well past 100. So what, exactly, are they complaining about?

{ The Economist | Continue reading }

art { Matthieu Bourel }

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 }

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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 }

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 }

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 }

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 }

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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 }

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 }

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 }

{ 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 }

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 }

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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 }

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 }