Heightened fearfulness as a developmental adaptation.

Although we find many merits to Grossmann's fearful ape hypothesis, unlike Grossmann, we see heightened fearfulness as an ontogenetic adaptation, signaling helplessness and fostering caregiving during infancy, which subsequently became exapted to promote cooperation. We also argue that, rather than being the "breeding ground" for enhanced infant fearfulness, cooperative care is more likely the evolved product of enhanced fearfulness.

Young children's attributes are better conveyed by voices than by faces.

The purpose of this study was to explore how young children's vocal and facial cues contribute to conveying to adults important information about children's attributes when presented together. In particular, the study aimed to disentangle whether children's vocal or facial cues, if either, are more dominant when both types of cues are displayed in a contradictory mode. To do this, we assigned 127 college students to one of three between-participants conditions. In the Voices-Only condition, participants listened to four pairs of synthetized voices simulating the voices of 4-5-year-old and 9-10-year-old children verbalizing a neutral-content sentence. Participants needed to indicate which voice was better associated with a series of 14 attributes organized into four trait dimensions (Positive Affect, Negative Affect, Intelligence, and Helpless), potentially meaningful in young child-adult interactions. In the Consistent condition, the same four pairs of voices delivered in the Voices-Only condition were presented jointly with morphed photographs of children's faces of equivalent age. In the Inconsistent condition, the four pairs of voices and faces were paired in a contradictory manner (immature voices with mature faces vs. mature voices with immature faces). Results revealed that vocal cues were more effective than facial cues in conveying young children's attributes to adults and that women were more efficient (i.e., faster) than men in responding to children's cues. These results confirm and extend previous evidence on the relevance of children's vocal cues to signaling important information about children's attributes and needs during their first 6 years of life.

Developing evolutionary psychology: Commentary on Narvaez et al. (2022).

Narvaez et al. (2022), in their article "Evolving Evolutionary Psychology," argue that mainstream evolutionary psychology is based on misguided neo-Darwinian adaptationist thinking and an antiquated computationalist, "mind-as-computer" framework and offer their own developmentally informed theory as an alternative. While applauding Narvaez et al. for promoting the role of development in evolutionary explication and as a potential metatheory for psychology, we point out that contemporary evolutionary-developmental accounts address the shortcomings of mainstream evolutionary psychology they describe, while maintaining an adaptationist perspective that includes a central role of evolved, domain-specific information-processing mechanisms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Children's Evolved Learning Abilities and Their Implications for Education.

In this article, I examine children's evolved learning mechanisms that make humans the most educable of animals. These include (1) skeletal perceptual and cognitive mechanisms that get fleshed out over the course of development, mainly through play; (2) a high level of plasticity that is greatest early in life but that persists into adulthood; (3) remarkable social-learning capabilities; and (4) dispositions toward exploration and play. I next examine some evolutionary mismatches-conflicts between psychological mechanisms evolved in ancient environments and their utility in modern ones-specifically with respect to modern educational systems. I then suggest some ways educators can take advantage of children's evolved learning abilities to minimize the effects of evolutionary mismatches, including (1) following developmentally appropriate practices (which are also evolutionarily appropriate practices), (2) increasing opportunities for physical activities, (3) increasing opportunities to learn through play, and (4) taking advantage of stress-adapted children's "hidden talents." I argue that evolutionary theory informs teachers and parents about how children evolved to learn and can result in more-enlightened teaching methods that will result in a more enjoyable and successful learning experiences for children.

Relapse of Plasmodium vivax and Plasmodium ovale Malaria With and Without Primaquine Treatment in a Nonendemic Area.

BACKGROUND: The effect of primaquine in preventing Plasmodium vivax relapses from dormant stages is well established. For Plasmodium ovale, the relapse characteristics and the use of primaquine is not as well studied. We set to evaluate the relapsing properties of these 2 species, in relation to primaquine use among imported malaria cases in a nonendemic setting. METHODS: We performed a nationwide retrospective study of malaria diagnosed in Sweden 1995-2019, by reviewing medical records of 3254 cases. All episodes of P. vivax (n = 972) and P. ovale (n = 251) were selected for analysis. RESULTS: First time relapses were reported in 80/857 (9.3%) P. vivax and 9/220 (4.1%) P. ovale episodes, respectively (P < .01). Without primaquine, the risk for relapse was higher in P. vivax, 20/60 (33.3%), compared to 3/30 (10.0%) in P. ovale (hazard ratio [HR] 3.5, 95% confidence interval [CI] 1.0-12.0). In P. vivax, patients prescribed primaquine had a reduced risk of relapse compared to episodes without relapse preventing treatment, 7.1% vs 33.3% (HR 0.2, 95% CI .1-.3). In P. ovale, the effect of primaquine on the risk of relapse did not reach statistical significance, with relapses seen in 2.8% of the episodes compared to 10.0% in patients not receiving relapse preventing treatment (HR 0.3, 95% CI .1-1.1). CONCLUSIONS: The risk of relapse was considerably lower in P. ovale than in P. vivax infections indicating different relapsing features between the two species. Primaquine was effective in preventing P. vivax relapse. In P. ovale, relapse episodes were few, and the supportive evidence for primaquine remains limited.

Voices as Cues to Children's Needs for Caregiving.

The aim of this study was to explore the role of voices as cues to adults of children's needs for potential caregiving during early childhood. To this purpose, 74 college students listened to pairs of 5-year-old versus 10-year-old children verbalizing neutral-content sentences and indicated which voice was better associated with each of 14 traits, potentially meaningful in interactions between young children and adults. Results indicated that children with immature voices were perceived more positively and as being more helpless than children with mature voices. Children's voices, regardless of the content of speech, seem to be a powerful source of information about children's need for caregiving for parents and others during the first six years of life.

A Cascade Model of Sociodevelopmental Events Leading to Men's Perpetration of Violence Against Female Romantic Partners.

Conceptually driven by life history theory, the current study investigated a hypothesized hierarchy of behaviors leading to men's perpetration of violence in intimate relationships. Using a series of hierarchical regressions, we tested a causal cascade model on data provided by 114 men in a committed romantic relationship. The results supported the hypothesized hierarchy of sociodevelopmental events: (1) men's childhood experiences with their parents' parental effort predicted men's life history strategies; (2) men's life history strategies predicted men's behavioral self-regulation; (3) men's self-regulation predicted men's perceptions of partner infidelity risk; (4) perceptions of infidelity risk predicted men's frequency of engagement in nonviolent mate retention behaviors; (5) men's mate retention behaviors predicted men's frequency of partner-directed violence. The overall cascade model explained 36% of variance in men's partner-directed violence.

Adolescents' sensititvity to children's supernatural thinking: A preparation for parenthood? / Receptividad de los adolescentes al pensamiento sobrenatural de los niños: ¿una preparación para la paternidad?

BACKGROUND: Young children often use magical explanations to account for ordinary phenomena (e.g., "The sun's not out today because it is mad"). We labeled these explanations supernatural thinking. Previous research reports that supernatural thinking attributed to preschool-age children evokes both positive affect and perceptions of helplessness from both adults and older (14-17 years old) but not younger (10-13 years old) adolescents. In this study, we asked if cues of cognitive immaturity are more influential in affecting adolescents' judgments of children than physical cues (faces). METHOD: 245 adolescents aged between 10 and 17 rated pairs of children who physically and/or cognitively resembled either a 4- to 7-year-old or an 8- to 10-year-old child in three between-subject conditions (Consistent, Inconsistent, Faces-Only) for 14 traits classified into four trait dimensions (Positive Affect, Negative Affect, Intelligence, Helplessness). RESULTS: For both younger and older adolescents, cognitive cues had a greater influence on judgments than facial cues. However, only the older adolescents demonstrated a positive bias for children expressing immature supernatural thinking. CONCLUSIONS: Adopting an evolutionary developmental perspective, we interpreted this outcome in late (but not early) adolescence as preparation for potential parenthood

ANTECEDENTES: los niños pequeños emplean a menudo explicaciones mágicas para referirse a fenómenos cotidianos (por ejemplo, "El sol no sale hoy porque está enfadado"). Nosotros etiquetamos estas explicaciones como pensamiento sobrenatural. Investigaciones anteriores muestran que el pensamiento sobrenatural atribuido a niños en edad preescolar evoca afecto positivo y percepción de desamparo en adultos y adolescentes mayores (14-17 años) pero no en adolescentes jóvenes (10-13 años). En este estudio nos preguntamos si las señales de inmadurez cognitiva son más influyentes en los juicios de los adolescentes que las señales físicas (caras). MÉTODO: 245 adolescentes de 10 a 17 años evaluaron pares de niños que emulaban físicamente y/o cognitivamente a niños de 4 a 7 años o niños de 8 a 10 años en tres condiciones (Consistente, Inconsistente, Solo-Caras) respecto a 14 rasgos clasificados en cuatro dimensiones (Afecto Positivo, Afecto Negativo, Inteligencia, Desamparo). RESULTADOS: tanto en adolescentes jóvenes como en mayores, las señales cognitivas tuvieron mayor influencia que las señales faciales. Sin embargo, solo los adolescentes mayores mostraron un sesgo positivo hacia niños que expresaban pensamientos sobrenaturales. CONCLUSIÓN: adoptando una perspectiva evolucionista del desarrollo, interpretamos este resultado en la adolescencia tardía (no temprana) como preparación para la paternidad

Adolescents' sensitivity to children's supernatural thinking: A preparation for parenthood?

BACKGROUND: Young children often use magical explanations to account for ordinary phenomena (e.g., "The sun's not out today because it is mad"). We labeled these explanations supernatural thinking. Previous research reports that supernatural thinking attributed to preschool-age children evokes both positive affect and perceptions of helplessness from both adults and older (14-17 years old) but not younger (10-13 years old) adolescents. In this study, we asked if cues of cognitive immaturity are more influential in affecting adolescents' judgments of children than physical cues (faces). METHOD: 245 adolescents aged between 10 and 17 rated pairs of children who physically and/or cognitively resembled either a 4- to 7-year-old or an 8- to 10-year-old child in three between-subject conditions (Consistent, Inconsistent, Faces-Only) for 14 traits classified into four trait dimensions (Positive Affect, Negative Affect, Intelligence, Helplessness). RESULTS: For both younger and older adolescents, cognitive cues had a greater influence on judgments than facial cues. However, only the older adolescents demonstrated a positive bias for children expressing immature supernatural thinking. CONCLUSIONS: Adopting an evolutionary developmental perspective, we interpreted this outcome in late (but not early) adolescence as preparation for potential parenthood.

A Metatheory for Cognitive Development (or "Piaget is Dead" Revisited).

In 1997, I argued that with the loss of Piaget's theory as an overarching guide, cognitive development had become disjointed and a new metatheory was needed to unify the field. I suggested developmental biology, particularly evolutionary theory, as a candidate. Here, I examine the increasing emphasis of biology in cognitive development research over the past 2 decades. I describe briefly the emergence of evolutionary developmental psychology and examine areas in which proximal and distal biological causation have been particularly influential. I argue that developmental biology will continue to increasingly influence research and theory in cognitive development and that evolutionary theory is well on its way to becoming a metatheory, not just for cognitive development, but for developmental psychology generally.

How Children Invented Humanity.

I use the commentaries of Legare, Clegg, and Wen and of Frankenhuis and Tiokhin as jumping-off points to discuss an issue hinted at both in my essay and their commentaries: How a developmental perspective can help us achieve a better understanding of evolution. I examine briefly how neoteny may have contributed to human morphology; how developmental plasticity in great apes, and presumably our common ancestor with them, may have led the way to advances in social cognition; and how the "invention" of childhood contributed to unique human cognitive abilities. I conclude by acknowledging that not all developmentalists have adopted an evolutionary perspective, but that we are approaching a time when an evolutionary perspective will be implicit in the thinking of all psychologists.

Children's supernatural thinking as a signalling behaviour in early childhood.

In this study, we analysed the reaction times of 137 college students when making decisions on pairs of hypothetical children verbalizing different types of vignettes and/or exhibiting different physical appearance (photographs of faces). Vignettes depicted immature and mature versions of both supernatural (e.g., 'The sun's not out today because it's mad' vs. 'The sun's not out today because the clouds are blocking it') and natural ('I can remember all 20 cards!' vs. 'I can remember 6 or 7 cards') explanations to ordinary phenomena. Photographs of children's faces were morphed with a physical appearance of approximately 4-7 years old or approximately 8-10 years old. In earlier research, immature supernatural thinking produced positive-affect reactions from adults and older adolescents (14-18 years old) towards young children, with cognitive cues being more important than physical-appearance cues in influencing adults' judgements. Reaction times to make decisions varied for the Supernatural and Natural vignettes and for the immature and mature vignettes/faces, reflecting the differential cognitive effort adults used for making decisions about aspects of children's physical appearance and verbal expressions. The findings were interpreted in terms of the critical role that young children's immature supernatural thinking has on adults' perception, analogous to the evolved role of immature physical features on adults' perception of infants.

Cognitive cues are more compelling than facial cues in determining adults' reactions towards young children.

Previous research has demonstrated the significant influence that both children's facial features (Lorenz, 1943) and children's cognitive expressions (Bjorklund, Hernández Blasi, and Periss, 2010) have on adults' perception of young children. However, until now, these two types of cues have been studied independently. The present study contrasted these two types of cues simultaneously in a group of college students. To this purpose, we designed five experimental conditions (Consistent, Inconsistent, Mature-Face, Immature-Face, and Faces-Only) in which we varied the presentation of a series of mature and immature vignettes (including two previously studied types of thinking: natural thinking and supernatural thinking) associated with a series of more mature and less mature children's faces. Performance in these conditions was contrasted with data from a Vignettes-Only condition taken from Bjorklund et al. (2010). Results indicated that cognitive cues were more powerful than facial cues in determining adults' perceptions of young children. From an evolutionary developmental perspective, we suggest that facial cues are more relevant to adults during infancy than during the preschool period, when, with the development of spoken language, the verbalized expressions of children's thoughts become the principal cues influencing adults' perceptions, with facial cues playing a more secondary role.

An introduction to evolutionary developmental psychology.

Evolutionary developmental psychology represents a synthesis of modern evolutionary theory and developmental psychology. Here we introduce the special issue on evolutionary developmental psychology by briefly discussing the history of this field and then summarizing the variety of topics that are covered. In this special issue, leading researchers provide a collection of theoretical and empirical articles that highlight recent findings and propose promising areas for future research.

Self-reported rates of interpersonal conflict vary as a function of questionnaire format: why age-related trends in disagreement (and other events) may not be what they seem.

Two studies examine whether self-reports of interpersonal conflict differ as a function of how the question is asked. In Study 1, 56 U.S. college students (M = 20.7 years) completed different versions of a questionnaire, four times, at one week intervals. Participants reported more conflicts with the aid of memory prompts than without, an effect that was especially strong when questions focused on events from the previous day. In Study 2, 123 middle-school students (M = 11.08 years) and 128 primary school students (M = 8.2 years) from the same region completed one of two questionnaires describing conflict during the previous day. Children reported more conflicts with memory prompts than without. The effect was twice as strong for younger children than older children. The findings suggest that increases in reports of conflict across the transition into adolescence may be due to improvements in the ability to recall and recount events in the absence of memory cues.

Prospective memory in preschool children: influences of agency, incentive, and underlying cognitive mechanisms.

Prospective memory (PM) is remembering to perform an action in the future and is crucial to achieving goal-directed activities in everyday life. Doing so requires that an intention is encoded, retained during a delay interval, and retrieved at the appropriate time of execution. We examined PM ability in preschool children by manipulating factors related to agency and incentive. We further explored how metacognition, executive functioning, and theory of mind-factors known to account for individual differences in PM-influenced performance on these PM tasks. A sample of 31 preschool children were asked to carry out a delayed intention or to remind an adult to carry out an intention that was of high or low incentive to the children. Findings indicated that individual differences in theory of mind were related to individual differences in preschoolers' performance on low-incentive PM tasks, independent of executive functioning contributions, whereas individual differences in executive functioning were related to performance on the high-incentive tasks. These findings suggest that changes in theory of mind and executive functioning are important to consider in models of PM and that different PM tasks (e.g., high vs. low incentive) may involve different cognitive requirements for young children.

Beyond mental health: an evolutionary analysis of development under risky and supportive environmental conditions: an introduction to the special section.

Evolutionary approaches to behavior have increasingly captured the attention and imagination of academics and laypeople alike. One part of this trend has been the increasing influence of evolutionary theory in developmental science. The articles in this special section of Developmental Psychology attempt to demonstrate why an evolutionary analysis is needed to more fully understand the contexts and contingencies of development. The 3 theoretical articles articulate the core evolutionary logic underlying conditional adaptation (and maladaptation) to both stressful and supportive environmental conditions over development. These theoretical articles are then followed by 9 empirical articles that test these evolutionary-developmental theories and hypotheses. Finally, 6 commentaries evaluate the prospects, pitfalls, and implications of this body of work.

Cognitive "babyness": developmental differences in the power of young children's supernatural thinking to influence positive and negative affect.

Perceptions of maturational status may play an important role in facilitating caretaking and resources toward children expressing them. Previous work has revealed evidence that cues of cognitive immaturity foster positive perceptions in adults toward young children at a time during their lives when they are most dependent on adult care. In the current series of studies, the authors investigated when during development these biases emerge. They tested American and Spanish adolescents ranging from 10 to 17 years of age. Each participant rated a series of vignettes presenting different expressions of immature and mature thinking attributed to young children. Results revealed that older adolescents performed similarly to adults tested in previous studies (D. F. Bjorklund, C. Hernández Blasi, & V. A. Periss, 2010), rating positively expressions of supernatural thinking (e.g., animism) compared with other forms of immature cognition labeled as natural (e.g., overestimation). Both male and female participants 14 years and older favored children expressing the immature supernatural cognition on traits reflecting positive affect (e.g., endearing, likeable), while associating greater negative affect (e.g., sneaky, impatient with) with children expressing immature natural cognition. However, younger adolescents consistently rated all forms of immature thinking less positively than mature thinking, suggesting that a positive bias for some forms of immature thinking develops during adolescence. Based on an evolutionary developmental framework, the authors suggest that supernatural thinking may have a unique role in humans, fostering positive perceptions of young children in older adolescents (and adults) as they prepare themselves for the possible role of parenthood.

Evolutionary developmental psychology.

The field of evolutionary developmental psychology can potentially broaden the horizons of mainstream evolutionary psychology by combining the principles of Darwinian evolution by natural selection with the study of human development, focusing on the epigenetic effects that occur between humans and their environment in a way that attempts to explain how evolved psychological mechanisms become expressed in the phenotypes of adults. An evolutionary developmental perspective includes an appreciation of comparative research and we, among others, argue that contrasting the cognition of humans with that of nonhuman primates can provide a framework with which to understand how human cognitive abilities and intelligence evolved. Furthermore, we argue that several <> aspects of childhood (e.g., play and immature cognition) serve both as deferred adaptations as well as imparting immediate benefits. Intense selection pressure was surely exerted on childhood over human evolutionary history and, as a result, neglecting to consider the early developmental period of children when studying their later adulthood produces an incomplete picture of the evolved adaptations expressed through human behavior and cognition.