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- Catalano, Ralph A., et al.
(författare)
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Collective Optimism and Selection Against Male Twins in Utero
- 2020
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press (CUP). - 1832-4274 .- 1839-2628. ; 23:1, s. 45-50
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Tidskriftsartikel (refereegranskat)abstract
- Scholarly literature claims that health declines in populations when optimism about investing in the future wanes. This claim leads us to describe collective optimism as a predictor of selection in utero. Based on the literature, we argue that the incidence of suicide gauges collective optimism in a population and therefore willingness to invest in the future. Using monthly data from Sweden for the years 1973-2016, we test the hypothesis that the incidence of suicide among women of child-bearing age correlates inversely with male twin births, an indicator of biological investment in high-risk gestations. We find that, as predicted by our theory, the incidence of suicide at month t varies inversely with the ratio of twin to singleton male births at month t + 3. Our results illustrate the likely sensitivity of selection in utero to change in the social environment and so the potential for viewing collective optimism as a component of public health infrastructure.
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| 2. |
- Catalano, Ralph, et al.
(författare)
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A novel indicator of selection in utero
- 2023
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Ingår i: EVOLUTION MEDICINE AND PUBLIC HEALTH. - : Oxford University Press (OUP). - 2050-6201. ; 11:1, s. 244-250
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Tidskriftsartikel (refereegranskat)abstract
- Background and objectives: Selection in utero predicts that population stressors raise the standard for how quickly fetuses must grow to avoid spontaneous abortion. Tests of this prediction must use indirect indicators of fetal loss in birth cohorts because vital statistics systems typically register fetal deaths at the 20th week of gestation or later, well after most have occurred. We argue that tests of selection in utero would make greater progress if researchers adopted an indicator of selection against slow-growing fetuses that followed from theory, allowed sex-specific tests and used readily available data. We propose such an indicator and assess its validity as a dependent variable by comparing its values among monthly birth cohorts before, and during, the first 10 months of the COVID-19 pandemic in Sweden.Methodology: We apply Box-Jenkins methods to 50 pre-pandemic birth cohorts (i.e., December 2016 through January 2020) and use the resulting transfer functions to predict counterfactual values in our suggested indicator for selection for ten subsequent birth cohorts beginning in February 2020. We then plot all 60 residual values as well as their 95% detection interval. If birth cohorts in gestation at the onset of the pandemic lost more slow-growing fetuses than expected from history, more than one of the last 10 (i.e. pandemic-exposed) residuals would fall below the detection interval.Results: Four of the last 10 residuals of our indicator for males and for females fell below the 95% detection interval.Conclusions and implications: Consistent with selection in utero, Swedish birth cohorts in gestation at the outset of the COVID-19 pandemic included fewer than expected infants who grew slowly in utero. Lay Summary Our findings suggest that the risk of spontaneously aborting a slow-growing fetus will increase during relatively stressful times.
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| 3. |
- Catalano, Ralph A., et al.
(författare)
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Twinning in Norway Following the Oslo Massacre : Evidence of a "Bruce Effect' in Humans
- 2016
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press (CUP). - 1832-4274 .- 1839-2628. ; 19:5, s. 485-491
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Tidskriftsartikel (refereegranskat)abstract
- Emerging theory and empirical work suggest that the Bruce Effect', or the increase in spontaneous abortion observed in non-human species when environments become threatening to offspring survival, may also appear in humans. We argue that, if it does, the effect would appear in the odds of twins among male and female live births. We test the hypothesis, implied by our argument, that the odds of a twin among male infants in Norway fell below, while those among females rose above, expected levels among birth cohorts in gestation in July 2011 when a deranged man murdered 77 Norwegians, including many youths. Results support the hypothesis and imply that the Bruce Effect operates in women to autonomically raise the standard of fetal fitness necessary to extend the gestation of twins. This circumstance has implications for using twins to estimate the relative contributions of genes and environment to human responses to exogenous stimuli.
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| 4. |
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| 5. |
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| 6. |
- Catalano, Ralph, et al.
(författare)
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Sildenafil and suicide in Sweden
- 2021
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Ingår i: European Journal of Epidemiology. - : Springer Nature. - 0393-2990 .- 1573-7284. ; 36:5, s. 531-537
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Tidskriftsartikel (refereegranskat)abstract
- Much theory asserts that sexual intimacy sustains mental health. Experimental tests of such theory remain rare and have not provided compelling evidence because ethical, practical, and cultural constraints bias samples and results. An epidemiologic approach would, therefore, seem indicated given the rigor the discipline brings to quasi-experimental research. For reasons that remain unclear, however, epidemiologist have largely ignored such theory despite the plausibility of the processes implicated, which engender, for example, happiness, feelings of belonging and self-worth, and protection against depression. We use an intent-to-treat design, implemented via interrupted time-series methods, to test the hypothesis that the monthly incidence of suicide, a societally important distal measure of mental health in a population, decreased among Swedish men aged 50-59 after July 2013 when patent rights to sildenafil (i.e., Viagra) ceased, prices fell, and its use increased dramatically. The test uses 102 pre, and 18 post, price-drop months. 65 fewer suicides than expected occurred among men aged 50-59 over test months following the lowering of sildenafil prices. Our findings could not arise from shared trends or seasonality, biased samples, or reverse causation. Our results would appear by chance fewer than once in 10,000 experiments. Our findings align with theory indicating that sexual intimacy reinforces mental health. Using suicide as our distal measure of mental health further implies that public health programming intended to address the drivers of self-destructive behavior should reduce barriers to intimacy in the middle-aged populations.
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| 7. |
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| 8. |
- Catalano, Ralph, et al.
(författare)
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Twinning during the pandemic : Evidence of selection in utero
- 2021
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Ingår i: Evolution, Medicine, and Public Health. - : Oxford University Press. - 2050-6201. ; 9:1, s. 374-382
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Tidskriftsartikel (refereegranskat)abstract
- Background and objectives: The suspicion that a population stressor as profound as the COVID-19 pandemic would increase preterm birth among cohorts in gestation at its outset has not been supported by data collected in 2020. An evolutionary perspective on this circumstance suggests that natural selection in utero, induced by the onset of the pandemic, caused pregnancies that would otherwise have produced a preterm birth to end early in gestation as spontaneous abortions. We test this possibility using the odds of a live-born twin among male births in Norway as an indicator of the depth of selection in birth cohorts.Methodology: We apply Box-Jenkins methods to 50 pre-pandemic months to estimate counterfactuals for the nine birth cohorts in gestation in March 2020 when the first deaths attributable to SARS-CoV-2 infection occurred in Norway. We use Alwan and Roberts outlier detection methods to discover any sequence of outlying values in the odds of a live-born twin among male births in exposed birth cohorts.Results: We find a downward level shift of 27% in the monthly odds of a twin among male births beginning in May and persisting through the remainder of 2020.Conclusions and implications: Consistent with evolutionary theory and selection in utero, birth cohorts exposed in utero to the onset of the COVID-19 pandemic yielded fewer male twins than expected.Lay Summary: Our finding of fewer than expected male twin births during the onset of the COVID-19 pandemic provides more evidence that evolution continues to affect the characteristics and health of contemporary populations.
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| 9. |
- Catalano, Ralph, et al.
(författare)
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Very low birthweight : Dysregulated gestation versus evolutionary adaptation
- 2014
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Ingår i: Social Science and Medicine. - : Elsevier BV. - 0277-9536 .- 1873-5347. ; 108, s. 237-242
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Tidskriftsartikel (refereegranskat)abstract
- Much medical literature attributes persistently high rates of very low birthweight (VLBW) to "dysregulated" gestation. We offer the alternative view that natural selection conserved well-regulated, though nonconscious, decisional biology that protects the reproductive fitness of women by spontaneously aborting gestations that would otherwise yield frail infants, particularly small males. Modern obstetric practice, however, converts some fraction of these erstwhile spontaneous abortions into live births of very small infants. We further propose that the nonconscious decisional biology of gestation exhibits preferences also seen in consciously made decisions. We hypothesize that the incidence of VLBW among male infants should vary with the population's self-reported intentions to assume financial risk. We apply time-series modeling to monthly birth counts by sex and weight from the Swedish Medical Birth Registry between January 1993 and December 2010. We gauge risk aversion with monthly data from the Micro Index of the Swedish Consumer Tendency Survey (MISCT). Consistent with our argument that nonconscious decisional biology shares risk aversion with conscious decisions, we find that the incidence of VLBW among male infants in Sweden varies with the population's self-reported intentions to assume financial risk. We find increases above expected odds of a very low weight infant among males born 1 month after increases above expected levels of self-reported risk aversion in the Swedish population. We offer this finding as support for the argument that persistently high rates of VLBW arise, at least in part, from a combination of medical interventions and mechanisms conserved by natural selection to protect reproductive fitness. (C) 2014 Elsevier Ltd. All rights reserved.
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| 10. |
- Gemmill, Alison, et al.
(författare)
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Do macroeconomic contractions induce or 'harvest' suicides? : A test of competing hypotheses
- 2015
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 69:11, s. 1071-1076
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Tidskriftsartikel (refereegranskat)abstract
- Background Researchers often invoke a mortality displacement or 'harvesting' mechanism to explain mortality patterns, such that those with underlying health vulnerabilities die sooner than expected in response to environmental phenomena, such as heat waves, cold spells and air pollution. It is unclear if this displacement mechanism might also explain observed increases in suicide following economic contraction, or if suicides are induced in persons otherwise unlikely to engage in self-destructive behaviour. Here, we test two competing hypotheses explaining an observed increase in suicides following unemployment-induction or displacement. Methods We apply time series methods to monthly suicide and unemployment data from Sweden for the years 2000-2011. Tests are conducted separately for working age (20-64 years old) men and women as well as older (aged 65 years and older) men and women. Results Displacement appeared among older men and women; an unexpected rise in unemployment predicted an increase in suicides 6 months later, followed by a significant decrease 8 months later. Induction appeared among working age men, but not among working age women; an unexpected rise in unemployment predicted an increase in suicides 4-6 months later. Conclusions Displacement and induction both appear to have operated following unexpected labour market contractions in Sweden, though with different population segments.
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