The social aspects of illness: Children's and parents' explanations of the relation between social categories and illness in a predominantly white U.S. sample.

The COVID-19 pandemic in the United States has had a disproportionate impact on Black, low-income, and elderly individuals. We recruited 175 predominantly white children ages 5-12 and their parents (N = 112) and asked which of two individuals (differing in age, gender, race, social class, or personality) was more likely to get sick with either COVID-19 or the common cold and why. Children and parents reported that older adults were more likely to get sick than younger adults, but reported few differences based on gender, race, social class, or personality. Children predominantly used behavioral explanations, but older children used more biological and structural explanations. Thus, children have some understanding of health disparities, and their understanding increases with age.

Deterministic or probabilistic: U.S. children's beliefs about genetic inheritance.

Do children think of genetic inheritance as deterministic or probabilistic? In two novel tasks, children viewed the eye colors of animal parents and judged and selected possible phenotypes of offspring. Across three studies (N = 353, 162 girls, 172 boys, 2 non-binary; 17 did not report gender) with predominantly White U.S. participants collected in 2019-2021, 4- to 12-year-old children showed a probabilistic understanding of genetic inheritance, and they accepted and expected variability in the genetic inheritance of eye color. Children did not show a mother bias but they did show two novel biases: perceptual similarity and sex-matching. These results held for unfamiliar animals and several physical traits (e.g., eye color, ear size, and fin type), and persisted after a lesson.

Two-photon Absorption and Photoionization of a Bacterial Phytochrome.

Phytochromes constitute a family of photosensory proteins that are utilized by various organisms to regulate several physiological processes. Phytochromes bind a bilin pigment that switches its isomeric state upon absorption of red or far-red photons, resulting in protein conformational changes that are sensed by the organism. Previously, the ultrafast dynamics in bacterial phytochrome was resolved to atomic resolution by time-resolved serial femtosecond X-ray diffraction (TR-SFX), showing extensive changes in its molecular conformation at 1 picosecond delay time. However, the large excitation fluence of mJ/mm2 used in TR-SFX questions the validity of the observed dynamics. In this work, we present an excitation-dependent ultrafast transient absorption study to test the response of a related bacterial phytochrome to excitation fluence. We observe excitation power-dependent sub-picosecond dynamics, assigned to the population of high-lying excited state Sn through resonantly enhanced two-photon absorption, followed by rapid internal conversion to the low-lying S1 state. Inspection of the long-lived spectrum under high fluence shows that in addition to the primary intermediate Lumi-R, spectroscopic signatures of solvated electrons and ionized chromophore radicals are observed. Supported by numerical modelling, we propose that under excitation fluences of tens of µJ/mm2 and higher, bacterial phytochrome partly undergoes photoionization from the Sn state in competition with internal conversion to the S1 state in 300 fs. We suggest that the extensive structural changes of related, shorter bacterial phytochrome, lacking the PHY domain, resolved from TR-SFX may have been affected by the ionized species. We propose approaches to minimize the two-photon absorption process by tuning the excitation spectrum away from the S1 absorption or using phytochromes exhibiting minimized or shifted S1 absorption.

Signal Transduction in an Enzymatic Photoreceptor Revealed by Cryo-Electron Microscopy.

Phytochromes are essential photoreceptor proteins in plants with homologs in bacteria and fungi that regulate a variety of important environmental responses. They display a reversible photocycle between two distinct states, the red-light absorbing Pr and the far-red light absorbing Pfr, each with its own structure. The reversible Pr to Pfr photoconversion requires covalently bound bilin chromophore and regulates the activity of a C-terminal enzymatic domain, which is usually a histidine kinase (HK). In plants, phytochromes translocate to nucleus where the C-terminal effector domain interacts with protein interaction factors (PIFs) to induce gene expression. In bacteria, the HK phosphorylates a response-regulator (RR) protein triggering downstream gene expression through a two-component signaling pathway. Although plant and bacterial phytochromes share similar structural composition, they have contrasting activity in the presence of light with most BphPs being active in the dark. The molecular mechanism that explains bacterial and plant phytochrome signaling has not been well understood due to limited structures of full-length phytochromes with enzymatic domain resolved at or near atomic resolution in both Pr and Pfr states. Here, we report the first Cryo-EM structures of a wild-type bacterial phytochrome with a HK enzymatic domain, determined in both Pr and Pfr states, between 3.75 and 4.13 Å resolution, respectively. Furthermore, we capture a distinct Pr/Pfr heterodimer of the same protein as potential signal transduction intermediate at 3.75 Å resolution. Our three Cryo-EM structures of the distinct signaling states of BphPs are further reinforced by Cryo-EM structures of the truncated PCM of the same protein determined for the Pr/Pfr heterodimer as well as Pfr state. These structures provide insight into the different light-signaling mechanisms that could explain how bacteria and plants see the light.

Some Correct Strategies Are Better Than Others: Individual Differences in Strategy Evaluations Are Related to Strategy Adoption.

Why do people shift their strategies for solving problems? Past work has focused on the roles of contextual and individual factors in explaining whether people adopt new strategies when they are exposed to them. In this study, we examined a factor not considered in prior work: people's evaluations of the strategies themselves. We presented undergraduate participants from a moderately selective university (N = 252; 64.8% women, 65.6% White, 67.6% who had taken calculus) with two strategies for solving algebraic word problems and asked them to rate these strategies and their own strategy on a variety of dimensions. Participants' ratings loaded onto two factors, which we label quality and difficulty. Participants' initial evaluations of the quality of the strategies were associated with whether they used the strategies at posttest, and this effect held even when controlling for individual and contextual factors. However, people's evaluations of the difficulty of the strategies were not consistently associated with their later adoption of those strategies. We also examined individual and contextual predictors of strategy ratings and strategy adoption. Participants' need for cognition and their spatial visualization ability were associated with their strategy evaluations, and the framing of the story problems was associated with their strategy adoption. The findings highlight that strategy adoption depends on multiple interacting factors, and that to understand strategy change, it is critical to examine how people evaluate strategies.

Like mother, like daughter: Adults' judgments about genetic inheritance.

Do adults think about genetic inheritance as a deterministic or probabilistic process? Do adults display systematic biases when reasoning about genetic inheritance? Knowing how adults think about genetic inheritance is valuable, both for understanding the developmental end point of these concepts and for identifying biases that persist even after formal education. In two studies, we examined adults' reasoning about genetic inheritance for familiar animals (Study 1) and unfamiliar animals (Study 2). First, participants were presented with animals that varied in eye color and were asked to judge whether each could be the offspring of a particular set of animal parents that had either the same or different eye colors. The potential offspring had eye colors that were either identical to the parents, blended the parents' eye colors, or differed from the parents. Next, participants predicted how six offspring of the animal parents would look. Participants judged a variety of choices as possible-not only the ones resembling the parents-suggesting that they thought genetic inheritance was a probabilistic process. Additionally, many participants thought that female offspring would look more like their mothers and male offspring would look more like their fathers. Thus, systemic biases in reasoning about inheritance persist into adulthood. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Detailed bugs or bugging details? The influence of perceptual richness across elementary school years.

Visualizations are commonly used in educational materials; however, not all visualizations are equally effective at promoting learning. Prior research has supported the idea that both perceptually rich and bland visualizations are beneficial for learning and generalization. We investigated whether the perceptual richness of a life cycle diagram influenced children's learning of metamorphosis, a concept that prior work suggests is difficult for people to generalize. Using identical materials, Study 1 (N = 76) examined learning and generalization of metamorphosis in first- and second-grade students, and Study 2 (N = 53) did so in fourth- and fifth-grade students. Bayesian regression analyses revealed that first and second graders learned more from the lesson with the perceptually rich diagram. In addition, fourth and fifth graders generalized more with the bland diagram, but these generalizations tended to be incorrect (i.e., generalizing metamorphosis to animals that do not undergo this type of change). These findings differ from prior research with adults, in which bland diagrams led to more correct generalizations, suggesting that the effect of perceptual richness on learning and generalization might change over development.

"When will it be over?" U.S. children's questions and parents' responses about the COVID-19 pandemic.

Parent-child conversations are important for children's cognitive development, children's ability to cope with stressful events, and can shape children's beliefs about the causes of illness. In the context of a global pandemic, families have faced a multitude of challenges, including changes to their routines, that they need to convey to their children. Thus, parent-child conversations about the coronavirus pandemic might convey information about the causes of illness, but also about how and why it is necessary for children to modify their behaviors to comply with new social norms and medical guidance. The main goal of this study was to examine the questions children ask about the COVID-19 pandemic and how parents answer them. This survey included responses from a national sample of 349 predominantly white parents of children between the ages of 3 and 12 recruited through Amazon's Mechanical Turk in United States. Parents reported that although children asked about COVID-19 and its causes (17.3%), children asked primarily about lifestyle changes that occurred as a result of the pandemic (24.0%) and safety (18.4%). Parents reported answering these questions by emphasizing that the purpose of different preventative measures was to protect the child (11.8%) or the family (42.7%) and providing reassurance (13.3%). Many parents discussed how it was their social responsibility to slow the spread of the virus (38.4%). Parents of younger children tended to shield them from information about COVID-19 (p = .038), while parents with more knowledge were more likely to provide explanations (p < .001). Our analysis shows that families not only discuss information about the virus but also information about changes to their lifestyle, preventative measures, and social norms.

Capturing Death in Animated Films: Can Films Stimulate Parent-Child Conversations about Death?

We present three studies examining death in children's animated films. Study 1 is a content analysis of 49 films. We found that death is often portrayed in films, but many deaths occurred off-screen. Deaths were mostly portrayed in a biologically accurate manner, but some films portrayed biological misconceptions. Study 2 (n = 433) reports on parents' attitudes and parent-child conversations about death in films. Children's questions about death in animated films were similar to their questions about death more generally. Animated films may provide a context for parent-child conversations about death, as parents often watched these films with their children. However, it appeared that few parents took advantage of this opportunity to talk about death with their children.

Breastfeeding education, early skin-to-skin contact and other strong determinants of exclusive breastfeeding in an urban population: a prospective study.

OBJECTIVE: The current study aims to demonstrate independent associations between social, educational and health practice interventions as determinants of exclusive breastfeeding in an urban Ecuadorian population. DESIGN: Prospective survival analyses. SETTING: Ecuadorian mother-child dyads in urban settings. PARTICIPANTS: We followed-up 363 mother-baby dyads who attended healthcare centres in Portoviejo, province of Manabi, for a median time (P25-P75) of 125 days (121-130 days). MAIN OUTCOME MEASURES: We performed a survival analysis, by setting the time-to-abandonment of exclusive breastfeeding measured in days of life, that is, duration of exclusive breastfeeding, periodically assessed by phone, as the primary outcome. Crude and adjusted mixed-effects Cox proportional hazards model were performed to estimate HRs for each explanatory variable. RESULTS: The incidence rate of abandonment of breastfeeding was 8.9 per 1000 person-days in the whole sample. Multivariate analysis indicated the three most significant protective determinants of exclusive breastfeeding were (a) sessions of prenatal breastfeeding education with an HR of 0.7 (95% CI: 0.5 to 0.9) per each extra session, (b) self-perception of milk production, with an HR of 0.4 (95% CI: 0.3 to 0.6) per each increase in the perceived quantity of milk production and (c) receiving early skin-to-skin contact with an HR of 0.1 (95% CI: <0.1 to 0.3) compared with those not receiving such contact, immediately after birth. CONCLUSIONS: Prenatal education on breastfeeding, self-perception of sufficient breast-milk production and early skin-to-skin contact appear to be strong protectors of exclusive breastfeeding among urban Ecuadorian mother-baby dyads.

Representing Variability: The Case of Life Cycle Diagrams.

Two foundational concepts in biology education are 1) offspring are not identical to their parents, and 2) organisms undergo changes throughout their lives. These concepts are included in both international and U.S. curricular standards. Research in psychology has shown that children often have difficulty understanding these concepts, as they are inconsistent with their intuitive theories of the biological world. Additionally, prior research suggests that diagrams are commonly used in instruction and that their features influence student learning. Given this prior work, we explored the characteristics of life cycle diagrams and discuss possible implications for student learning. We examined 75 life cycle diagrams from books, including five biology or general science textbooks and 25 specialized trade books focusing on biology for children. We also examined 633 life cycle diagrams from a publicly available online database of science diagrams. Most diagrams failed to show any within-species variability. Additionally, many diagrams had perceptually rich backgrounds, which prior research suggests might hinder learning. We discuss how the design characteristics of diagrams may reinforce students' intuitive theories of biology, which might make it difficult for students to understand key biological concepts in the future.

Evaluating and communicating about the healthiness of foods: Predictors of parents' judgments and parent-child conversations.

Parents are typically in charge of purchasing the food that their children eat, but little is known about how parents decide if particular foods are healthy for their children and how their beliefs about nutrition influence their children's beliefs. In two studies, we investigated how parents of children ages 4 to 12 (N = 826) make decisions about the healthiness of foods, when presented with different representations of the same nutritional information. Providing parents with nutritional information did not influence their ratings of how healthy food items are, compared to when they are shown only pictures of the foods. Parents reported talking with their children about nutrition, believed they are the best source of information for children about nutrition, and believed their nutrition beliefs influence their child's beliefs. Our findings highlight the role of prior knowledge in food cognition and how beliefs about foods are transmitted from parents to children.

Reframing mental illness: The role of essentialism on perceived treatment efficacy and stigmatization.

People believe that treatments for illnesses are effective when they target the cause of the illness. Prior work suggests that biological essentialist explanations of mental illness lead people to prefer medications or other pharmacological treatments. However, prior work has not distinguished between biological and essentialist explanations. In three studies (total n = 517), we presented adults with vignettes about an individual with an artificial mental illness and manipulated the descriptions to emphasize or de-emphasize essentialist characteristics. Critically, none of the vignettes made reference to a biological basis for the disorder. Participants rated their willingness to interact with the person described in the vignettes and how effective they believed drug treatment and talk therapy would be on the mental illness. Across the three studies, describing mental illness with an essentialist framing led participants to think drug treatments would be more effective, but there was no effect for stigma or perceived effectiveness of talk therapy. This effect appears to be mediated by how much participants essentialized individuals with the disorder. The first framing that participants encountered seemed to shape their reasoning for the remainder of the study, even if they saw conflicting framing later on. The framing manipulation had similar effects for individuals with and without a mental illness. Results suggest that it is important to consider how mental illness is framed to the general public as it might impact people's treatment preferences.

Embracing Death: Mexican Parent and Child Perspectives on Death.

A mixed-method approach was used to explore parent and child perspectives on death in Mexico. Parents' and children's death-related experiences and understanding of death were examined. While all children in this sample displayed a biological understanding of death, older children were less likely to endorse that all living things die. Children also displayed coexistence of beliefs related to death that can be attributed to both their biological and spiritual understanding of death. We also found that older children were more likely to report that a child should feel sad following the death of a loved one. These findings highlight how cultural practices shape the development of cognitive and affective processes related to death.

Do you remember being told what happened to grandma? The role of early socialization on later coping with death.

Using a mixed-methods approach, we examined how participants' memories of socialization regarding death might influence their self-reported coping with losses in childhood and adulthood. We recruited 318 adults to complete an online survey. Path analyses indicated that participants who remembered their parents shielding them less from issues related to death reported better coping as children and adults. Qualitative responses suggested participants wanted to receive more information about death from their parents as they went through the grieving process. We highlight the potential benefits of socializing children about death, and how it may aid in their coping with death-related events.

Strategy adoption depends on characteristics of the instruction, learner, and strategy.

Why do people change their strategies for solving problems? In this research, we tested whether negative feedback and the context in which learners encounter a strategy influence their likelihood of adopting that strategy. In particular, we examined whether strategy adoption varied when learners were exposed to a target strategy in isolation, in conjunction with their own current strategy, and in conjunction with another novel strategy. We also investigated the roles of individual differences, including learners' need for cognition and their confidence in their current strategies. In Study 1, undergraduate participants who encountered a target strategy in isolation were more likely to adopt it than participants who encountered it in the context of their own current strategy. Negative feedback, low confidence, and high need for cognition also predicted greater adoption. In Study 2, we examined whether rates of strategy adoption depended on the target strategy itself. Indeed, participants were more likely to adopt one strategy than the other, and the effects of feedback also varied across strategies. Individual differences-need for cognition and confidence-also influenced patterns of strategy adoption. These results suggest that strategy adoption depends on the confluence of many factors, including the context in which a target strategy is introduced, characteristics of the learner, and characteristics of the strategy itself.

Understanding Strategy Change: Contextual, Individual, and Metacognitive Factors.

Learning, development, and response to instruction often involve changes in the strategies that learners use to solve problems. In this chapter, our focus is on mathematical problem solving in both children and adults. We offer a selective review of research on three classes of factors that may influence processes of strategy change in mathematical problem solving: contextual factors, individual factors, and metacognitive factors. Contextual factors involve information that learners encounter in the learning context, such as feedback about prior strategies and examples of alternative strategies. Individual factors involve the abilities, dispositions, and knowledge that learners bring to the learning context. Metacognitive factors involve knowledge about strategies and factors that affect the application of strategies-including perceptions of problem difficulty, confidence in the strategies one already knows, and judgments about the qualities of alternative strategies. These factors operate both independently and in combination to influence learners' behavior. Therefore, we argue that scientific progress in understanding strategy change will require comprehensive conceptual models that specify how different factors come together to explain behavior. We discuss several such models, including vulnerability-trigger models, cumulative risk models, and dynamic systems models. Research guided by such models will contribute to greater progress in understanding processes of strategy use and strategy change.

Cognitive constraints influence an understanding of life-cycle change.

We investigated children's (n = 120; 3- to 11-year-olds) and adults' (n = 18) reasoning about life-cycle changes in biological organisms by examining their endorsements of four different patterns of life-span changes. Participants were presented with two separate tasks: (a) judging possible adult versions of a juvenile animal and (b) judging possible juvenile versions of an adult animal. The stimuli enabled us to examine the endorsement of four different patterns of change: identical growth, natural growth, dramatic change, and speciation. The results suggest that endorsement of the different patterns is influenced by age and familiarity. Young children and individuals confronted with unfamiliar organisms often endorsed an identical growth that emphasizes the stability of features over the life span and between parents and offspring. The results are interpreted as supporting the idea that cognitive constraints influence individuals' reasoning about biological change and that the influence of these constraints is most notable when individuals are young or are presented with unfamiliar biological organisms.

COMMENTARY: WHAT HEALS AND WHY? CHILDREN'S UNDERSTANDING OF MEDICAL TREATMENTS.

Lockhart and Keil have written an interesting monograph focusing on the development of reasoning about medicine, a relatively underexplored area of research with potentially broad implications with respect to the design of more-effective medical interventions. In a set of 15 studies with well over 2,200 participants, they examine how children and adults combine aspects of biological and psychological reasoning to create working models of medicine. Lockhart and Keil explore developmental changes in reasoning about illness and its treatment using medicines in terms of dualism (e.g., psychological vs. physical), spatial proximity, differential timing of effects, potential side effects, and treatment tradeoffs. This commentary highlights the novel contributions of this monograph, examines issues that need additional considerations, and makes suggestions for future research.

Adolescent Predictors of Incidence and Persistence of Suicide-Related Outcomes in Young Adulthood: A Longitudinal Study of Mexican Youth.

In recent years, Mexico has seen one of the largest increases in suicide rates worldwide, especially among adolescents and young adults. This study uses data from the 1,071 respondents who participated in a two-wave longitudinal study when they were between 12 and 17 years of age, and again when they were between 19 and 26 years of age. The World Mental Health Composite International Diagnostic Interview assessed suicidal behavior and DSM-IV mental disorders. We used Cox regressions to evaluate which sociodemographic and psychiatric factors and life events predicted the incidence and remission of suicide ideation, plan, and attempt throughout the 8-year span. The 8-year incidence of suicide ideation, plan, and attempt was 13.3%, 4.8%, and 5.9%, respectively. We found that the number of traumatic life events during childhood, no longer being in school, and tobacco use predicted which adolescents developed suicide behaviors as they transitioned into young adulthood. Psychiatric disorders, particularly anxiety disorders, played a larger role in the persistence of those who already had suicidal behaviors, while behavioral disorders played a role in the transition from ideation to attempt. This distinction may be useful for clinicians to assess the risk of suicide.