Parental Bias Research Articles

A macro role for imprinted clusters of microRNAs in the brain.

Evidence suggests that ~95% of the human genome may produce noncoding RNAs (ncRNAs). Approximately 30% of parentally imprinted transcripts are ncRNAs that are found abundantly--and in some cases specifically--in the brain; however, the role ncRNA plays during development and day-to-day life is not apparent. Interestingly, ~1,300 transcripts show a consistent parental expression bias in the brain. This is in contrast to most tissues that show only rare imprinted transcripts. Furthermore, there are only two clusters of imprinted small nucleolar RNA (snoRNA) encoding genes in mammals, which are also expressed in the brain. These clusters, Snrpn-Ube3a (Human 15q11-q13/Murine 7qC) and Dlk1-Dio3 (Human 14q32.2/Murine 12qF1) and rodent specific Sfmbt2 (Murine 2qA1), form the focus of this review. These imprinted clusters are localized to imprinted regions that are associated with processes involved in neuronal plasticity and several neurodevelopmental disorders. Several miRNAs from the Dlk1-Dio3 region are also involved in chromatin methylation and remodelling. The final loci of interest is the proximal region of murine chromosome 2 that contains Sfmbt2 and an overlapping antisense transcript that is unique within mice and rats. This suggests that Sfmbt2 may be in the process of becoming imprinted that is being driven by a cluster of intergenic miRNAs. Ultimately, imprinted clusters of ncRNA have the potential to offer novel insight into the understanding of the complex processes of cognition given their role in brain function.

Exploring Parental Predictors of Child Anxiety: The Mediating Role of Child Interpretation Bias

Separate lines of research have shown that higher levels of parental overcontrol and parental anxiety are related to higher levels of child anxiety. The mechanisms of transmission, however, are poorly understood. It has been theorized, though not empirically tested, that parental overcontrol and anxiety increase children's interpretation bias by signaling to the child that the environment is threatening (e.g. through modeling or restriction of autonomy), thus increasing the child's anxiety level. The present study investigated this theory using 75 parent-child dyads (parents aged 27-52, 82 % female; children aged 7-12, 52 % female, 80 % Caucasian). All parents were diagnosed with a primary anxiety disorder, while no child was diagnosed with an anxiety disorder. Children's interpretation bias, measured using ambiguous stories, was shown to partially mediate the relation between parental overcontrol and child anxiety and completely mediate the relation between parental anxiety and child anxiety. There was no significant relation between parental overcontrol and parental anxiety. Findings partially support theoretical models, which posit that higher levels of overcontrol and parental anxiety signal to children that their environment is threatening, perhaps increasing their threat appraisal of ambiguous situations and increasing their anxiety. Implications and directions for future research are discussed.

Do you know how I feel? Parents underestimate worry and overestimate optimism compared to child self-report

Three studies assessed parent–child agreement in perceptions of children’s everyday emotions in typically developing 4- to 11-year-old children. Study 1 (N=228) and Study 2 (N=195) focused on children’s worry and anxiety. Study 3 (N=90) examined children’s optimism. Despite child and parent reporters providing internally consistent responses, their perceptions about children’s emotional wellbeing consistently failed to correlate. Parents significantly underestimated child worry and anxiety and overestimated optimism compared to child self-report (suggesting a parental positivity bias). Moreover, parents’ self-reported emotions correlated with how they reported their children’s emotions (suggesting an egocentric bias). These findings have implications for developmental researchers, clinicians, and parents.

Imprinted Genes … and the Number Is?

Imprinted Genes … and the Number Is?

A Genome-Wide Survey of Imprinted Genes in Rice Seeds Reveals Imprinting Primarily Occurs in the Endosperm

Genomic imprinting causes the expression of an allele depending on its parental origin. In plants, most imprinted genes have been identified in Arabidopsis endosperm, a transient structure consumed by the embryo during seed formation. We identified imprinted genes in rice seed where both the endosperm and embryo are present at seed maturity. RNA was extracted from embryos and endosperm of seeds obtained from reciprocal crosses between two subspecies Nipponbare (Japonica rice) and 93-11 (Indica rice). Sequenced reads from cDNA libraries were aligned to their respective parental genomes using single-nucleotide polymorphisms (SNPs). Reads across SNPs enabled derivation of parental expression bias ratios. A continuum of parental expression bias states was observed. Statistical analyses indicated 262 candidate imprinted loci in the endosperm and three in the embryo (168 genic and 97 non-genic). Fifty-six of the 67 loci investigated were confirmed to be imprinted in the seed. Imprinted loci are not clustered in the rice genome as found in mammals. All of these imprinted loci were expressed in the endosperm, and one of these was also imprinted in the embryo, confirming that in both rice and Arabidopsis imprinted expression is primarily confined to the endosperm. Some rice imprinted genes were also expressed in vegetative tissues, indicating that they have additional roles in plant growth. Comparison of candidate imprinted genes found in rice with imprinted candidate loci obtained from genome-wide surveys of imprinted genes in Arabidopsis to date shows a low degree of conservation, suggesting that imprinting has evolved independently in eudicots and monocots.

Parental favouritism strategies in the asynchronously hatching European Roller (Coracias garrulus)

In altricial birds, resource allocation during early developmental stages is the result of an interaction between parental feeding decisions and scramble competition between nestmates. Hatching asynchrony in birds leads to a pronounced age hierarchy among their offspring. Therefore, whenever parents exert control over resource allocation parents feeding asynchronous broods should simultaneously assess individual offspring internal condition and age. In this study, we first studied whether the highly ultraviolet (UV) reflective body skin of nestlings in the asynchronous European Roller (Coracias garrulus; roller hereafter) relates to nestling quality. In a second stage, we experimentally studied parental biases in food allocation towards senior and junior sibling rollers in relation to a manipulation of UV reflectance of the skin of their offspring. Heavier roller nestlings had less brilliant and less UV saturated skins than weaker nestlings. In our experiment, we found that parents with large broods preferentially fed nestlings presenting skin coloration revealing small body size (i.e. control nestlings) over nestlings presenting skin coloration revealing large body size (i.e. UV-blocked nestlings). Within the brood, we found that parental food allocation strategy depended on nestling age: parents preferentially fed senior nestlings signalling small body size, but did not show preference between control and UV-blocked junior nestlings. These results emphasise that parent rollers use UV cues of offspring quality while balancing the age of their offspring to adjust their feeding strategies, and suggest that parents may adopt finely tuned strategies of control over resource allocation in asynchronous broods.

Does Wealth Increase Parental Investment Biases in Child Education?

Why fertility declines is still a matter of intense debate. One theory proposes that fertility decline may be partly driven by shifts in parental investment strategies: couples reduce family size as demographic and economic changes cause investment in the quality of children to become more important than investment in the quantity of children. A key driver for this change is a shift from a subsistence-based to a skills-based economy, in which education enhances child quality. Evolutionary anthropologists have modified this theory to propose that parental investment will diverge during the demographic transition according to resource availability: couples with the greatest access to resources will invest more in quality than in quantity of children. Here we test the impact of resources on educational investment in two populations on the cusp of fertility decline: the patrilineal Arsi Oromo of Ethiopia and the matrilineal Chewa of Malawi. In both populations, increased wealth is associated with greater biases in the allocation of education between children. In richer families, early-born children are prioritized over later-born ones, although early-born sons are favored in the patrilineal population and early-born daughters in the matrilineal population. Poorer families invest less in their children’s education but also discriminate less between children.

De novo rates and selection of large copy number variation

While copy number variation (CNV) is an active area of research, de novo mutation rates within human populations are not well characterized. By focusing on large (>100 kbp) events, we estimate the rate of de novo CNV formation in humans by analyzing 4394 transmissions from human pedigrees with and without neurocognitive disease. We show that a significant limitation in directly measuring genome-wide CNV mutation is accessing DNA derived from primary tissues as opposed to cell lines. We conservatively estimated the genome-wide CNV mutation rate using single nucleotide polymorphism (SNP) microarrays to analyze whole-blood derived DNA from asthmatic trios, a collection in which we observed no elevation in the prevalence of large CNVs. At a resolution of ∼30 kb, nine de novo CNVs were observed from 772 transmissions, corresponding to a mutation rate of μ = 1.2 × 10(-2) CNVs per genome per transmission (μ = 6.5 × 10(-3) for CNVs >500 kb). Combined with previous estimates of CNV prevalence and assuming a model of mutation-selection balance, we estimate significant purifying selection for large (>500 kb) events at the genome-wide level to be s = 0.16. Supporting this, we identify de novo CNVs in 717 multiplex autism pedigrees from the AGRE collection and observe a fourfold enrichment (P = 1.4 × 10(-3)) for de novo CNVs in cases of multiplex autism versus unaffected siblings, suggesting that many de novo CNV mutations contribute a subtle, but significant risk for autism. We observe no parental bias in the origin or transmission of CNVs among any of the cohorts studied.

The Importance of Imprinting in the Human Placenta

As a field of study, genomic imprinting has grown rapidly in the last 20 years, with a growing figure of around 100 imprinted genes known in the mouse and approximately 50 in the human. The imprinted expression of genes may be transient and highly tissue-specific, and there are potentially hundreds of other, as yet undiscovered, imprinted transcripts. The placenta is notable amongst mammalian organs for its high and prolific expression of imprinted genes. This review discusses the development of the human placenta and focuses on the function of imprinting in this organ. Imprinting is potentially a mechanism to balance parental resource allocation and it plays an important role in growth. The placenta, as the interface between mother and fetus, is central to prenatal growth control. The expression of genes subject to parental allelic expression bias has, over the years, been shown to be essential for the normal development and physiology of the placenta. In this review we also discuss the significance of genes that lack conservation of imprinting between mice and humans, genes whose imprinted expression is often placental-specific. Finally, we illustrate the importance of imprinting in the postnatal human in terms of several human imprinting disorders, with consideration of the brain as a key organ for imprinted gene expression after birth.

Visual cues and parental favouritism in a nocturnal bird

Visual signals are crucial for parent-offspring communication, although their functioning has been neglected for nocturnal birds. Here, we investigated parental preference for nestling coloration in nocturnal conditions--a question hitherto unexplored--in a nocturnal raptor, the scops owl (Otus scops). We assessed how parents allocated food during the night in relation to a manipulation of ultraviolet (UV) reflectance of the cere (skin above the beak) of their offspring. Reflectance of the cere shows a marked peak in the UV part of the spectrum, and location of the UV peak is related to nestling body mass (i.e. heavier nestlings have a UV peak at lower wavelengths). We found evidence of parental bias in favour of lighter offspring: UV-reduced nestlings gained more weight during the night than their control siblings. This study provides the first experimental evidence of the use of visual cues for parent-offspring communication in a nocturnal bird.

The Breathing Space of Ballad: Tennyson’s Stillborn Poetics

The Breathing Space of Ballad: Tennyson’s Stillborn Poetics D. B. Ruderman (bio) In April 1851, on Easter Sunday, Alfred Tennyson’s first child was stillborn. The child, a boy, was apparently strangled by the umbilical cord. Christopher Ricks reports that the poet never forgot this “‘great grief.’”1 Rather than send a death notice to the newspaper, Tennyson took it upon himself to “write some 60 letters” to inform friends and family of the news. What follows is representative: My dear Robert, I am quite sure you will feel with me. My poor little boy got strangled in being born. . . . I have suffered more than ever I thought I could have done for a child still born. . . . [H]e was the grandest-looking child I have ever seen. Pardon my saying this. I do not speak only as a father but as an Artist. . . . [H]e looked . . . majestic in his mysterious silence.2 Those accustomed to the poet’s guarded epistolary style may be surprised to read such a direct and open expression of grief: “I have suffered more that ever I thought I could have done.” Tennyson speaks as an artist and a father perhaps in order to justify the intensity of his attachment to the child, but his claim also suggests an inchoate aesthetic judgment, itself in the process of being born. According to this aesthetic, it is neither character nor action that determines the beauty of the stillborn child, but rather his arrested and unrealizable potential. Tennyson’s need to apologize—“Pardon my saying this”—is complicated. While he seems anxious on one hand to control the perception that parental bias may have skewed his evaluative judgment, there is also a sense in which his speech risks shattering the “mysterious silence” that uniquely marks the child’s majesty. It is as though he feels compelled to speak. This compulsion at once results in and precipitates an intense identification. I say that identification is both cause and effect of a compulsion to speak in order to foreground the ways in which the poetic description of a stillborn infant tends necessarily toward prosopopoeia. Any attempt to grant potential or futurity to the stillborn child breaks down the binaries of living-dead, speaking-silent, [End Page 151] and subject-object. And although the grammar suggests a linear relationship between the son’s passivity (got strangled) and the father’s active and ongoing suffering (he suffers because the son got strangled), the participles describing that relationship—“strangled” and “suffered”—are almost interchangeable. The more or less identical places they occupy in their respective sentences work toward destabilizing the causal, in this case filial, link. Additional mirrorings and reversals, implicit and explicit, occur throughout the passage. The roles of the father (pater, creator, “majestic,” sovereign) are hived off and given to the son, whereas the conventional positions of the son (admiration, identification, supplication) are assumed instead by the father. Even the fixed roles of the percipient and the perceived are tenuous, liable to subtle shifts. Thus, the “grandest-looking child” seems capable of looking back at his father—he “looked. . . .” This confusion—this fusing with—reproduces the mutability of object boundaries ascribed both to the state of infancy in nineteenth-century philosophy and natural science, and to the poetry of immediate experience in aesthetic theories from the period.3 Finally, Tennyson’s multiple connections to the child allow the reader an oblique identification—“I am quite sure you will feel with me.” In other words, Tennyson’s overflow of emotion interrupts and facilitates our empathetic identification with the child, with the result that his mediation (between stillborn child and reader) is at once transparent and thick. Tennyson maintains these slippages and reversals as well as this emotional pitch (a strained and strangely objective subjectivity) in nearly all the extant letters, repeating several times how beautiful the child was, how he kissed his “poor, pale hands,” and expressing his open embarrassment at being so moved: “I am foolish [i.e., childish] enough to be affected with all this” (Letters, 2:14). An unfinished fragment of poetry survives: Little bosom not yet cold, Noble forehead made for thought, Little hands of mighty mould...

Do anxious parents interpretive biases towards threat extend into their child's environment?

Anxiety disorders are known to run in families [Turner, S. M., Beidel, D. C., & Costello, A. (1987). Psychopathology in the offspring of anxiety disorder patients. Journal of Consulting and Clinical Psychology, 55(2), 229–235] and environmental factors may largely account for the concordance between parental and child anxieties. Cognitive psychology models emphasise the importance of interpretive biases towards threat in the maintenance of anxiety and it is well established that anxious adults and children display similar interpretive biases and that these biases in anxious parents and their children are correlated. This raises the question of whether anxious cognitions/cognitive style may be transmitted from parent to child. We propose that this is more likely if anxious parents demonstrate interpretive biases not only about potential threats in their own environment but also about potential threats in their child's environment. Forty parents completed a recognition memory measure of interpretation bias adapted from Eysenck, Mogg, May, Richards, and Mathews (1991) [Bias in interpretation of ambiguous sentences related to threat in anxiety. Journal of Abnormal Psychology, 100(2), 144–150] to measure biases in response to potentially threat provoking situations involving themselves and their child. The interpretive biases demonstrated by parents were similar across situations involving themselves and their children. As expected, parental interpretive biases were further modified by anxiety with higher levels of parental anxiety associated with more negative interpretive biases about situations in their own and their child's environment, although this association was significantly stronger for potentially threat provoking situations in their own environment. These results are consistent with parent's interpretive biases extending beyond their own environment into their child's environment, although future research should continue to consider the mechanisms by which anxious parents may transmit fear cognitions to their children.

The Demand for Sons

Do parents have preferences over the gender of their children, and if so, does this have negative consequences for daughters versus sons? In this paper, we show that child gender affects the marital status, family structure, and fertility of a significant number of American families. Overall, a first-born daughter is significantly less likely to be living with her father compared to a first-born son. Three factors are important in explaining this gap. First, women with first-born daughters are less likely to marry. Strikingly, we also find evidence that the gender of a child in utero affects shotgun marriages. Among women who have taken an ultrasound test during pregnancy, mothers who have a girl are less likely to be married at delivery than those who have a boy. Second, parents who have first-born girls are significantly more likely to be divorced. Third, after a divorce, fathers are much more likely to obtain custody of sons compared to daughters. These three factors have serious negative income and educational consequences for affected children. What explains these findings? In the last part of the paper, we turn to the relationship between child gender and fertility to help sort out parental gender bias from competing explanations for our findings. We show that the number of children is significantly higher in families with a first-born girl. Our estimates indicate that first-born daughters caused approximately 5500 more births per year, for a total of 220,000 more births over the past 40 years. Taken individually, each piece of empirical evidence is not sufficient to establish the existence of parental gender bias. But taken together, the weight of the evidence supports the notion that parents in the U.S. favour boys over girls.

The Relationships among Parental Attachment, Self-Enhancement Bias, and Perception of Facial Expression of University Students

The Relationships among Parental Attachment, Self-Enhancement Bias, and Perception of Facial Expression of University Students

Evolution of parental favoritism among different-aged offspring

The theories of intrafamilial conflict and parental investment have yet to examine how parents’ decisions about resource allocation are influenced by the fact that their offspring may be different in age. Two counteracting effects of offspring growth on parental allocation of resources have deterred the development of a formal model: A parent may favor older offspring due to their greater reproductive value or favor younger offspring due to their higher marginal returns from extra resources. Using an evolutionary invasion analysis in class-structured populations, I present a formal model that explores how a parent should allocate its resources among different-aged offspring from the viewpoint of the parent. The parent’s evolutionarily stable strategy is to allocate its resources such that the marginal benefit to each offspring’s survival, weighted by the survival probability to the reproductive age, is equal to the marginal cost to the parent’s residual survival. Two general situations are considered in which younger offspring obtain higher marginal returns than older offspring. In nearly all circumstances, a parent is expected to bias its resources toward older offspring. The results may account for the widespread yet puzzling phenomenon of parental bias toward older offspring in view of previous theories of intrafamilial conflict. Key words: evolutionarily stable strategy, hatching asynchrony, invasion analysis, offspring age, parental investment, reproductive value. [Behav Ecol]

Lower Extremity Muscle Strength in 6- to 8-Year-Old Children Using Hand-Held Dynamometry

The purposes of the study were to establish isometric torque reference values for healthy 6- to 8-year-old children for 6 lower extremity muscles and determine the effects of gender, age, height, weight, and physical activity upon strength. A hand-held dynamometer was used to obtain force/torque values for 154 children. Age-referenced force/torque and cutoff values are provided for each muscle group. Torque increased with age and height for all muscles and with weight for all muscles except knee extensors. No gender differences were found. Children who participated in 3 or more hours per week in organized sports were stronger in 4 of 6 muscles; the number of hours spent in active play did not affect torque. This study provides hand-held dynamometer strength reference values to enable clinicians to determine if clients of the same age, height, and weight have muscle weakness.

The Influence of Abnormal Sex Differences in Life Expectancy on National Happiness

Countries with better health, as indexed by life expectancy, score higher on subjective well-being (SWB). It was predicted that deviations from the average sex difference in life expectancy (reflecting reproductive competition among males and discrimination against females) would be inversely related to happiness. Regression analysis of SWB for 178 countries found that deviations from the average sex difference in life expectancy were predictive of unhappiness controlling for life expectancy, national wealth, and income inequality. Countries with a relative scarcity of female children (used as an index of parental bias) were less happy. Societies in which there is an undue burden on the health and survival of either sex are thus unhappy ones due to gender-specific disadvantage and associated gender conflict.

The Attribution of Hostile Intent in Mothers, Fathers and Their Children

Child externalising symptoms are associated with a bias towards attributing hostile intent to others. We examined the role of parental attributions in the development of this hostile attribution bias in children. The parents of 134 children aged 5-7 years responded to hypothetical social scenarios examining a) their general tendency to attribute hostile intent to the ambiguous behaviour of others, and b) hostile attributions made specifically to their child. Children's own attributions of hostile intent and levels of externalising symptomatology were assessed. The results indicated that child externalising symptoms were positively associated with both a generalised tendency towards the attribution of hostile intent and child-specific hostile attributions in parents. Child externalising symptoms were themselves associated with hostile attributions made by the child. However, no direct associations were observed between parental and child attributions of hostile intent. Thus, although the results suggest a role for parental social information processing biases in the development of child externalising symptoms, a direct transmission of such biases from parent to child was not supported.

The Potential Biases in Studying the Relationship between Asthma and Microbial Infection

Objective. To assess bias in parent reports of asthma status of children and detection bias of medical records-based asthma ascertainment and to examine effects of such bias on the association between asthma status and infections.Methods. A prospective cohort study was conducted to compare the correlations between the frequency of acute illnesses and that of medical evaluations between children with or without asthma according to parental report and medical record review by following a group of children who were enrolled in the Mayo Clinic Sick Child Care Program in Rochester, Minnesota. Parents completed a self-administered questionnaire to determine asthma status of their child. Also, comprehensive medical record reviews were conducted to determine asthma status of each subject by applying predetermined criteria for asthma.Results. A convenience sample of 115 parents and their children participated in this study. The mean age of the parents who participated in the study was 32.8 years (standard deviation: 5.4 years); 93% were female (mothers); and 90% were white. Of the 115 children who participated in this study, 84% were reported to be white and 49% were female. The mean age of the children was 2 years (standard deviation: 1.0 year). Parents whose children had asthma by report appeared to be less likely to seek medical evaluations (Spearman's rho: 0.42,p = 0.11) when their children had acute illnesses, compared to those of non-asthmatic children (rho: 0.64,p < 0.001). Concerns that asthmatic patients (rho: 0.62,p < 0.001) are more likely to see health care providers and undergo medical evaluations and laboratory tests when they have acute illnesses than non-asthmatic patients (rho: 0.64,p < 0.001) are not supported by our study.Conclusion. Parental report bias needs to be considered carefully when studying the relationship between asthma and microbial infection.

Pediatric intracranial aneurysms: durability of treatment following microsurgical and endovascular management

Longer life expectancies and differences in the underlying disease in children with aneurysms raise important issues concerning the choice of microsurgical or endovascular therapy. The authors reviewed their experience at one institution regarding patients treated between 1977 and 2003, focusing on the issue of treatment durability.Forty-three aneurysms in 32 pediatric patients were identified. The patients ranged in age from 2 months to 18 years (mean 11.7 years). Only seven patients (22%) presented with subarachnoid hemorrhage, and in nine patients (28%) significant medical comorbidities were present. Aneurysm locations included the internal carotid artery (13 lesions), middle cerebral artery (11 lesions), and the basilar artery/vertebrobasilar junction (six lesions). Of the 43 lesions, 17 (40%) were giant aneurysms and 22 (51%) exhibited fusiform/dolichoectatic morphological features. Thirteen patients underwent microsurgery, 16 endovascular treatment, and three observation. Complete aneurysm obliteration rates were 94 and 82% in the microsurgical and endovascular groups, respectively. There were no deaths in either group, and neurological morbidity rates were comparable. Over time, 14% of endovascularly treated aneurysms recurred, and in 19% of these patients de novo aneurysms developed (mean follow-up duration 5.7 years). In contrast, there were no recurrences in the microsurgically treated aneurysms and only one de novo aneurysm (6%).Both microsurgical and endovascular therapies can be conducted safely to treat pediatric aneurysms. Microsurgery may be more efficacious in completely eliminating the aneurysm and its effects more durable over the extended lifetime of these patients. Parental biases toward nonoperative therapy should be thoroughly addressed before ultimately selecting a treatment strategy.