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1.
Horm Behav ; 150: 105317, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36731300

RESUMO

A number of studies have been claimed to show that ovarian hormones, whose levels fluctuate throughout the menstrual cycle, affect consumer preferences and financial decisions. The present article aims to critically analyze the literature examining associations between the phases of the menstrual cycle (peri-ovulatory vs. non-ovulatory) with particular consumer preferences (especially regarding clothing choices) and economic decisions (especially in regards to economic games and risk-taking). A search for studies was conducted in Web of Science and Scopus between 2004 and 2022, by combining keywords of the menstrual cycle, consumer preferences, and economic decisions. Once articles were selected, we identified the main findings, the characteristics of the population, and the methods for determining the phases of the cycle. We performed a p-curve analysis on previously reported statistically significant effects. These analyses find evidence for associations between peri-ovulatory status and specific consumer preferences, most strongly for appearance-enhancing products. They yield no compelling evidence for associations between peri-ovulatory status and financial decisions and risk-taking. We offer provisional conclusions and call for additional studies that possess sufficient statistical power to detect true meaningful effects, especially in the domain of financial decisions.


Assuntos
Comportamento do Consumidor , Progesterona , Feminino , Humanos , Ciclo Menstrual
2.
Horm Behav ; 146: 105276, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36356458

RESUMO

A substantial body of literature has examined how women's psychology and behavior vary as a function of conception risk across the ovarian cycle. These effects are widely believed to be outcomes of hormonal regulation, in particular effects of estrogens (E) and progesterone (P). Increasingly, researchers have sought to test predictions about how psychological processes or behavior vary as a function of conception risk by examining associations with estrogen (e.g., estradiol) and progesterone levels. Yet issues regarding how best to assess these associations arise. Should hormone levels be log-transformed? Do hormone ratios best capture their joint effects? How important are hormone interactions? How should outliers be treated? Across two large datasets, we examined hormonal predictors of conception risk, estimated from day of a luteinizing hormone (LH) surge. Log-transformed E and P levels predicted conception risk better than raw E and P levels did. The raw E/P ratio was a relatively poor predictor, whereas the log-transformed ratio (ln[E/P]) was a relatively good predictor. E × P interactions were detected but weak. Outliers were frequent, especially in distributions of raw hormone levels. Hormone measures predicted two psychological outcomes in these datasets-sexual desire and preferences for strength and muscularity-in parallel to how strongly they predicted conception risk. These results give rise to several recommendations regarding treatment of hormone measures and their use in analyses.


Assuntos
Ciclo Menstrual , Progesterona , Humanos , Feminino , Progesterona/análise , Ciclo Menstrual/fisiologia , Estradiol/análise , Libido/fisiologia , Hormônio Luteinizante
3.
Emerg Top Life Sci ; 6(3): 311-322, 2022 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-35994000

RESUMO

Developmental instability (DI) is an individual's inability to produce a specific developmental outcome under a given set of conditions, generally thought to result from random perturbations experienced during development. Fluctuating asymmetry (FA) - asymmetry on bilateral features that, on average, are symmetrical (or asymmetry deviating from that arising from design) - has been used to measure DI. Dating to half a century ago, and accelerating in the past three decades, psychological researchers have examined associations between FA (typically measured on bodily or facial features) and a host of outcomes of interest, including psychological disorders, cognitive ability, attractiveness, and sexual behavior. A decade ago, a meta-analysis on findings from nearly 100 studies extracted several conclusions. On average, small but statistically reliable associations between FA and traits of interest exist. Though modest, these associations are expected to greatly underestimate the strength of associations with underlying DI. Despite the massive sample size across studies, we still lack a good handle on which traits are most strongly affected by DI. A major methodological implication of the meta-analysis is that most studies have been, individually, woefully underpowered to detect associations. Though offering some intriguing findings, much research is the past decade too has been underpowered; hence, the newer literature is also likely noisy. Several large-scale studies are exceptions. Future progress depends on additional large-scale studies and researchers' sensitivity to power issues. As well, theoretical assumptions and conceptualizations of DI and FA driving psychological research may need revision to explain empirical patterns.


Assuntos
Comportamento Sexual , Humanos , Fenótipo , Tamanho da Amostra
4.
Front Psychol ; 13: 900737, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35795438

RESUMO

How do women's sexual interests change across their ovulatory cycles? This question is one of the most enduring within the human evolutionary behavioral sciences. Yet definitive, agreed-upon answers remain elusive. One empirical pattern appears to be robust: Women experience greater levels of sexual desire and interest when conceptive during their cycles. But this pattern is not straightforward or self-explanatory. We lay out multiple possible, broad explanations for it. Based on selectionist reasoning, we argue that the conditions that give rise to sexual interests during conceptive and non-conceptive phases are likely to differ. Because conceptive and non-conceptive sex have distinct functions, the sexual interests during conceptive and non-conceptive phases are likely to have different strategic ends. We discuss provisional evidence consistent with this perspective. But the exact nature of women's dual sexuality, if it exists, remains unclear. Additional empirical research is needed. But perhaps more crucially, this topic demands additional theory that fruitfully guides and interprets future empirical research.

5.
Psychoneuroendocrinology ; 142: 105802, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35598493

RESUMO

Hormone ratios are often used to capture the joint effect (or "balance") of two hormones with opposing or mutually suppressive effects. Despite some statistical and interpretative problems, hormone ratios are being increasingly used to examine associations of testosterone/cortisol, estradiol/progesterone, testosterone/estradiol, and other hormone pairs. Here we discuss a methodological problem that has not been previously recognized, namely, the striking lack of robustness of raw hormone ratios in the face of measurement error. Hormone levels are measured with error, both due to inability of assays to perfectly assess concentrations "in the tube" and due to discrepancies between levels at the time of sample collection and effective levels that produce the physiological and/or behavioral effect of interest. Noise in measured hormone levels can be substantially exaggerated by ratios, especially when the distribution of the hormone at the denominator is positively skewed, as is frequently observed. To evaluate the extent of this problem and explore the conditions that exacerbate it, we present two sets of simulations, one using idealized distributions and one using empirically observed distributions from studies of estrogen and progesterone. Results show that the validity of raw hormone ratios-the correlation between measured levels and underlying effective levels-drops rapidly in the presence of realistic levels of measurement error. Log-ratios are much more robust to measurement error, and their validity is more stable across samples; under some conditions (e.g., moderate amounts of noise with positively correlated hormone levels), they may provide a more valid measurement of the underlying raw ratio than the measured raw ratio itself. These findings have important implications for research that uses hormone ratios as predictors.


Assuntos
Estradiol , Progesterona , Estrogênios , Manejo de Espécimes , Testosterona
6.
Arch Sex Behav ; 51(2): 751-756, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33398700
7.
Perspect Psychol Sci ; 17(2): 311-333, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34597198

RESUMO

The COVID-19 pandemic has extensively changed the state of psychological science from what research questions psychologists can ask to which methodologies psychologists can use to investigate them. In this article, we offer a perspective on how to optimize new research in the pandemic's wake. Because this pandemic is inherently a social phenomenon-an event that hinges on human-to-human contact-we focus on socially relevant subfields of psychology. We highlight specific psychological phenomena that have likely shifted as a result of the pandemic and discuss theoretical, methodological, and practical considerations of conducting research on these phenomena. After this discussion, we evaluate metascientific issues that have been amplified by the pandemic. We aim to demonstrate how theoretically grounded views on the COVID-19 pandemic can help make psychological science stronger-not weaker-in its wake.


Assuntos
COVID-19 , Humanos , Pandemias , SARS-CoV-2
8.
J Pers Soc Psychol ; 121(2): 432-440, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34636588

RESUMO

Arslan et al. (2020) conducted a large-scale, preregistered daily diary study on over 400 normally ovulating women. Of core interest were hypotheses that women's ratings of their partner's sexual attractiveness moderate associations of fertility status with women's own extrapair sexual desires, their own interest in in-pair sex, and their partners' mate retention tactics. The authors claim that "no evidence for moderator effects" (p. 426) was found. In fact, their own analyses reported in their supplementary material show robust evidence for moderation effects. Moreover, a new reanalysis using a more comprehensive composite measure of male partner sexual attractiveness yielded even stronger results. Effect size estimates are consistent with the existence of large, meaningful moderation effects, revealing that this study actually does show evidence of moderation effects. Additional analyses show similarly strong moderator effects on male proprietariness. We discuss the findings in the context of reliance on binary (significant vs. nonsignificant) labels and the pitfalls of underreporting effects. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Comportamento Sexual , Parceiros Sexuais , Feminino , Fertilidade , Humanos , Libido , Masculino , Ovulação
9.
Horm Behav ; 130: 104934, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33476675

RESUMO

When current conditions are probabilistically less suitable for successful reproduction than future conditions, females may prevent or delay reproduction until conditions improve. Throughout human evolution, social support was likely crucial to female reproductive success. Women may thus have evolved fertility regulation systems sensitive to cues from the social environment. However, current understanding of how psychological phenomena might affect female ovarian function is limited. In this study, we examined whether cues of reduced social support-social ostracism-impact women's hormone production. Following an in-lab group bonding task, women were randomly assigned to a social exclusion (n = 88) or social inclusion (n = 81) condition. After social exclusion, women with low background levels of social support experienced a decrease in estradiol relative to progesterone. In contrast, socially-included women with low background social support experienced an increase in estradiol relative to progesterone. Hormonal changes in both conditions occurred specifically when women were in their mid-to-late follicular phase, when baseline estradiol is high and progesterone is low. Follow-up analyses revealed that these changes were primarily driven by changes in progesterone, consistent with existing evidence for disruption of ovarian function following adrenal release of follicular-phase progesterone. Results offer support for a potential mechanism by which fecundity could respond adaptively to the loss or lack of social support.


Assuntos
Progesterona , Isolamento Social , Estradiol , Feminino , Fertilidade , Fase Folicular , Humanos , Reprodução
10.
Horm Behav ; 109: 25-37, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30685468

RESUMO

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature-including p-curve analyses of published findings; and, (2) "opening the file drawer" and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.


Assuntos
Hidrocortisona/fisiologia , Modelos Teóricos , Personalidade/fisiologia , Predomínio Social , Testosterona/fisiologia , Agressão/fisiologia , Agressão/psicologia , Animais , Humanos , Primatas , Reprodução/fisiologia , Classe Social
11.
Brain Behav Immun ; 70: 61-75, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29499302

RESUMO

Behavioral researchers have increasingly become interested in the idea that chronic, low-grade inflammation is a pathway through which social and behavioral variables exert long-term effects on health. Much research in the area employs putative inflammatory biomarkers to infer an underlying state of inflammation. Interleukin 6 (IL-6) and C-reactive protein (CRP, whose production is stimulated by IL-6) are arguably the two most commonly assayed biomarkers. Yet, in contrast with near-universal assumptions in the field, discoveries in immunology over the past two decades show that neither IL-6 nor CRP are unambiguous inflammatory markers. IL-6 operates through two distinct signaling pathways, only one of which is specifically upregulated during inflammation; both pathways have a complex range of effects and influence multiple physiological processes even in absence of inflammation. Similarly, CRP has two isoforms, one of which is produced locally in inflamed or damaged tissues. The other isoform is routinely produced in absence of inflammation and may have net anti-inflammatory effects. We propose a functional framework to account for the multiple actions of IL-6 and CRP. Specifically, we argue that both molecules participate in somatic maintenance efforts; hence elevated levels indicate that an organism is investing in protection, preservation, and/or repair of somatic tissue. Depending on the state of the organism, maintenance may be channeled into resistance against pathogens (including inflammation), pathogen tolerance and harm reduction, or tissue repair. The findings and framework we present have a range of potential implications for the interpretation of empirical findings in this area-a point we illustrate with alternative interpretations of research on socioeconomic status, stress, and depression.


Assuntos
Proteína C-Reativa/fisiologia , Interleucina-6/metabolismo , Interleucina-6/fisiologia , Animais , Biomarcadores , Proteína C-Reativa/metabolismo , Depressão/imunologia , Depressão/fisiopatologia , Humanos , Inflamação/imunologia , Inflamação/fisiopatologia , Transdução de Sinais/fisiologia , Classe Social , Estresse Psicológico/imunologia , Estresse Psicológico/fisiopatologia
12.
Horm Behav ; 90: 64-74, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28254475

RESUMO

Oxytocin (OT) has been implicated in the formation and maintenance of various social relationships, including human romantic relationships. Competing models predict, alternatively, positive or negative associations between naturally-occurring OT levels and romantic relationship quality. Empirical tests of these models have been equivocal. We propose a novel hypothesis ('Identify and Invest') that frames OT as an allocator of psychological investment toward valued, vulnerable relationships, and test this proposal in two studies. In one sample of 75 couples, and a second sample of 148 romantically involved individuals, we assess facets of relationships predicting changes in OT across a thought-writing task regarding one's partner. In both studies, participants' OT change across the task corresponded positively with multiple dimensions of high relationship involvement. However, increases in participants' OT also corresponded to their partners reporting lower relationship involvement. OT increases, then, reflected discrepancies between assessments of self and partner relationship involvement. These findings are robust in a combined analysis of both studies, and do not significantly differ between samples. Collectively, our findings support the 'Identify and Invest' hypothesis in romantic couples, and we argue for its relevance across other types of social bonds.


Assuntos
Relações Interpessoais , Ocitocina/metabolismo , Parceiros Sexuais/psicologia , Adolescente , Adulto , Características da Família , Feminino , Humanos , Masculino , Satisfação Pessoal , Saliva/metabolismo , Adulto Jovem
13.
Horm Behav ; 91: 122-135, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27530218

RESUMO

Which hormones are implicated in human social bonding and affiliation? And how does field research speak to this issue? We begin by laying out a broad view of how endocrine hormones in general modulate life history allocations of energy and other resources, and the ways in which their neuromodulatory functions must be understood within a broader conceptualization of how they have been shaped to affect allocations. We then turn to four specific hormones or hormone families that have received much attention: oxytocin, opioids, prolactin, and progesterone. Each plays a role in regulating psychological capacities and propensities that underlie individuals' interactions with important social targets. Yet in no case is it clear exactly what regulatory roles these hormones play. We suggest several directions for future research.


Assuntos
Relações Interpessoais , Peptídeos Opioides/metabolismo , Ocitocina/metabolismo , Progesterona/metabolismo , Prolactina/metabolismo , Comportamento Social , Animais , Humanos
14.
Horm Behav ; 78: 211-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26592455

RESUMO

In naturally cycling women, Roney and Simmons (2013) examined hormonal correlates of their desire for sexual contact. Estradiol was positively associated, and progesterone negatively associated, with self-reported desire. The current study extended these findings by examining, within a sample of 33 naturally cycling women involved in romantic relationships, hormonal correlates of sexual attraction to or interests in specific targets: women's own primary partner or men other than women's primary partner. Women's sexual interests and hormone (estradiol, progesterone, and testosterone) levels were assessed at two different time points. Whereas estradiol levels were associated with relatively greater extra-pair sexual interests than in-pair sexual interests, progesterone levels were associated with relatively greater in-pair sexual interests. Both hormones specifically predicted in-pair sexual desire, estradiol negatively and progesterone positively. These findings have implications for understanding the function of women's extended sexuality - their sexual proceptivity and receptivity outside the fertile phase, especially during the luteal phase.


Assuntos
Estradiol/fisiologia , Libido/fisiologia , Ciclo Menstrual/fisiologia , Progesterona/fisiologia , Comportamento Sexual/fisiologia , Parceiros Sexuais , Adolescente , Adulto , Estradiol/metabolismo , Feminino , Humanos , Ciclo Menstrual/metabolismo , Progesterona/metabolismo , Adulto Jovem
15.
Schizophr Res ; 156(1): 71-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24768440

RESUMO

BACKGROUND: Cognitive deficits are prominent in schizophrenia and represent promising endophenotypes for genetic research. METHODS: The current study investigated the importance of two conceptually distinct genetic aggregates, one based on copy number variations (uncommon deletion burden), and one based on single nucleotide polymorphisms identified in recent risk studies (genetic risk score). The impact of these genetic factors, and their interaction, was examined on cognitive endophenotypes defined by principal component analysis (PCA) in a multi-center sample of 50 patients with schizophrenia and 86 controls. PCA was used to identify three different types of executive function (EF: planning, fluency, and inhibition), and in separate analyses, a measure general cognitive ability (GCA). RESULTS: Cognitive deficits were prominent among individuals with schizophrenia, but no group differences were evident for either genetic factor. Among patients the deletion burden measures predicted cognitive deficits across the three EF components and GCA. Further, an interaction was noted between the two genetic factors for both EF and GCA and the observed patterns of interaction suggested antagonistic epistasis. In general, the set of genetic interactions examined predicted a substantial portion of variance in these cognitive endophenotypes. LIMITATIONS: Though adequately powered, our sample size is small for a genetic study. CONCLUSIONS: These results draw attention to genetic interactions and the possibility that genetic influences on cognition differ in patients and controls.


Assuntos
Transtornos Cognitivos/genética , Endofenótipos , Predisposição Genética para Doença/genética , Esquizofrenia/complicações , Esquizofrenia/genética , Adulto , Análise de Variância , Transtornos Cognitivos/etiologia , Feminino , Seguimentos , Estudos de Associação Genética , Humanos , Masculino , Testes Neuropsicológicos , Análise de Componente Principal , Escalas de Graduação Psiquiátrica , Adulto Jovem
16.
PLoS One ; 9(3): e91993, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24647612

RESUMO

We explored the social-signaling hypothesis that variability in exogenous pain sensitivities across the menstrual cycle is moderated by women's current romantic relationship status and hence the availability of a solicitous social partner for expressing pain behaviors in regular, isochronal ways. In two studies, we used the menstrual calendars of healthy women to provide a detailed approximation of the women's probability of conception based on their current cycle-day, along with relationship status, and cold pressor pain and ischemic pain sensitivities, respectively. In the first study (n = 135; 18-46 yrs., Mage = 23 yrs., 50% natural cycling), we found that naturally-cycling, pair-bonded women showed a positive correlation between the probability of conception and ischemic pain intensity (r = .45), associations not found for single women or hormonal contraceptive-users. A second study (n = 107; 19-29 yrs., Mage = 20 yrs., 56% natural cycling) showed a similar association between greater conception risk and higher cold-pressor pain intensity in naturally-cycling, pair-bonded women only (r = .63). The findings show that variability in exogenous pain sensitivities across different fertility phases of the menstrual cycle is contingent on basic elements of women's social environment and inversely correspond to variability in naturally occurring, perimenstrual symptoms. These findings have wide-ranging implications for: a) standardizing pain measurement protocols; b) understanding basic biopsychosocial pain-related processes; c) addressing clinical pain experiences in women; and d) understanding how pain influences, and is influenced by, social relationships.


Assuntos
Ciclo Menstrual/fisiologia , Limiar da Dor/psicologia , Dor/fisiopatologia , Dor/psicologia , Parceiros Sexuais , Adolescente , Adulto , Feminino , Fertilização , Humanos , Pessoa de Meia-Idade , Probabilidade , Parceiros Sexuais/psicologia , Adulto Jovem
17.
Psychol Sci ; 24(10): 2106-10, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23965377

RESUMO

Women's sexuality, unlike that of most mammals, is not solely defined by sexual receptivity during the short window of fertility. Women demonstrate extended sexuality (in which they initiate and accept sexual advances outside of the fertile phase) more than any other mammalian female. In this light, surprisingly little research has addressed the functions of women's luteal-phase sexuality. On the basis of theory and comparative evidence, we propose that women's initiation of sex during nonfertile phases evolved in part to garner investment from male partners. If so, women should be particularly prone to initiate luteal-phase sex when the potential marginal gains are greatest. Results from a study of 50 heterosexual couples showed that women increasingly initiate sex in the luteal phase (but not the fertile phase) when they perceive their partners' investment to lag behind their own. These findings provide evidence for the distinct nature of women's extended sexuality and may contribute to a more comprehensive understanding of women's sexuality.


Assuntos
Coito/psicologia , Fertilidade , Relações Interpessoais , Fase Luteal/psicologia , Parceiros Sexuais , Adolescente , Adulto , Evolução Biológica , Coito/fisiologia , Feminino , Heterossexualidade/fisiologia , Heterossexualidade/psicologia , Humanos , Modelos Lineares , Fase Luteal/fisiologia , Masculino , Fatores Sexuais , Comportamento Sexual , Adulto Jovem
18.
Biol Psychiatry ; 73(6): 540-5, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23237311

RESUMO

BACKGROUND: General cognitive ability is usually lower in individuals with schizophrenia, partly due to genetic influences. However, the specific genetic features related to general cognitive ability are poorly understood. Individual variation in a specific type of mutation, uncommon genetic deletions, has recently been linked with both general cognitive ability and risk for schizophrenia. METHODS: We derived measures of the aggregate number of "uncommon" deletions (i.e., those occurring in 3% or less of our combined samples) and the total number of base pairs affected by these deletions in individuals with schizophrenia (n = 79) and healthy control subjects (n = 110) and related each measure to the first principal component of a large battery of cognitive tests, a common technique for characterizing general cognitive ability. These two measures of mutation load were also evaluated for relationships with total brain gray matter, white matter, and lateral ventricle volume. RESULTS: The groups did not differ on genetic variables. Multivariate general linear models revealed a group (control subjects vs. patients) × uncommon deletion number interaction, such that the latter variable was associated with lower general cognitive ability and larger ventricles in patients but not control subjects. CONCLUSIONS: These data suggest that aggregate uncommon deletion burden moderates central features of the schizophrenia phenotype.


Assuntos
Cognição , Deleção de Genes , Ventrículos Laterais/patologia , Esquizofrenia/genética , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Adulto , Atrofia/patologia , Estudos de Casos e Controles , Variações do Número de Cópias de DNA/genética , Feminino , Predisposição Genética para Doença/genética , Humanos , Masculino , Fibras Nervosas Mielinizadas/patologia , Fibras Nervosas Amielínicas/patologia , Neuroimagem , Testes Neuropsicológicos
19.
Biol Rev Camb Philos Soc ; 87(4): 856-73, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22564253

RESUMO

Throughout the second and third trimesters, the human placenta (and the placenta in other anthropoid primates) produces substantial quantities of corticotropin-releasing hormone (placental CRH), most of which is secreted into the maternal bloodstream. During pregnancy, CRH concentrations rise over 1000-fold. The advantages that led selection to favour placental CRH production and secretion are not yet fully understood. Placental CRH stimulates the production of maternal adrenocorticotropin hormone (ACTH) and cortisol, leading to substantial increases in maternal serum cortisol levels during the third trimester. These effects are puzzling in light of widespread theory that cortisol has harmful effects on the fetus. The maternal hypothalamic-pituitary-adrenal (HPA) axis becomes less sensitive to cortisol during pregnancy, purportedly to protect the fetus from cortisol exposure. Researchers, then, have often looked for beneficial effects of placental CRH that involve receptors outside the HPA system, such as the uterine myometrium (e.g. the placental clock hypothesis). An alternative view is proposed here: the beneficial effect of placental CRH to the fetus lies in the fact that it does stimulate the production of cortisol, which, in turn, leads to greater concentrations of glucose in the maternal bloodstream available for fetal consumption. In this view, maternal HPA insensitivity to placental CRH likely reflects counter-adaptation, as the optimal rate of cortisol production for the fetus exceeds that for the mother. Evidence pertaining to this proposal is reviewed.


Assuntos
Glicemia/fisiologia , Hormônio Liberador da Corticotropina/fisiologia , Placenta/fisiologia , Adaptação Fisiológica , Feminino , Humanos , Troca Materno-Fetal , Gravidez
20.
Philos Trans R Soc Lond B Biol Sci ; 366(1583): 3375-88, 2011 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-22042915

RESUMO

Mate preferences may operate in part to mitigate the threats posed by infectious disease. In this paper, we outline various ways in which preferring healthy mates can offer direct benefits in terms of pathogen avoidance and indirect benefits in terms of heritable immunity to offspring, as well as the costs that may constrain mate preferences for health. We then pay special attention to empirical work on mate preferences in humans given the depth and breadth of research on human mating. We review this literature and comment on the degree to which human mate preferences may reflect preferences for health.


Assuntos
Doenças Transmissíveis/imunologia , Transmissão de Doença Infecciosa/prevenção & controle , Preferência de Acasalamento Animal/fisiologia , Reprodução/imunologia , Animais , Doenças Transmissíveis/psicologia , Feminino , Humanos , Masculino
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