Samuli Helle
Biographic Data
| ID | 108273 |
|---|---|
| NAME | Samuli Helle |
| GIVEN NAMES | Samuli |
| FAMILY NAME | Helle |
| SIGNATURE | HELLE S |
| AFFILIATIONS | University of Turku |
| ORCID | 0000-0002-6216-3759 |
| VERIFIED | Yes |
| TOTAL WORKS | 13 |
| TOTAL CITATIONS | 11 |
| AUTHOR COUNT | 13 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2004 |
| LATEST PUBLICATION YEAR | 2024 |
| H-INDEX | 2 |
Testing the expensive-tissue hypothesis’ prediction of inter-tissue competition using causal modelling with latent variables
The expensive-tissue hypothesis (ETH) posited a brain–gut trade-off to explain how humans evolved large, costly brains. Versions of the ETH interrogating gut or other body tissues have been tested in non-human animals, but not humans. We collected brain and body composition data in 70 South Asian women and used structural equation modelling with instrumental variables, an approach that handles threats to causal inference including measurement err…
Parental Investment by Birth Fathers and Stepfathers
This study investigates the determinants of paternal investment by birth fathers and stepfathers. Inclusive fitness theory predicts higher parental investment in birth children than stepchildren, and this has consistently been found in previous studies. Here we investigate whether paternal investment varies with childhood co-residence duration and differs between stepfathers and divorced birth fathers by comparing the investment of (1) stepfather…
Support for populist candidates predicted by declining social capital and an increase in suicides
Do "Dark" Personality Features Buffer Against Adversity? The Associations Between Cumulative Life Stress, the Dark Triad, and Mental Distress
Stressful life events have a major impact on adverse mental health outcomes, although not all individuals are equally affected. According to the buffering hypothesis, there may be personality traits that protect individuals against mental distress in the face of adversity, playing thus a moderating role between life stressors and mental distress. In the present online study ( N = 574), Dark Triad of personality (i.e., Machiavellianism, narcissism…
Accounting for measurement error in human life history trade‐offs using structural equation modeling
OBJECTIVES: Revealing causal effects from correlative data is very challenging and a contemporary problem in human life history research owing to the lack of experimental approach. Problems with causal inference arising from measurement error in independent variables, whether related either to inaccurate measurement technique or validity of measurements, seem not well-known in this field. The aim of this study is to show how structural equation m…
Women's reproductive success and the preference for Dark Triad in men's faces
Sex of preceding sibling and anthropometrics of subsequent offspring at birth and in young adulthood
In many mammal species with sexual dimorphism producing sons is energetically more demanding to the mother than producing daughters. Although some studies in humans have suggested that offspring born after a brother have a smaller birth weight and adult height when compared with those born after a sister, little is known about this intergenerational cost of producing sons. We aimed to study whether the sex of preceding sibling is associated with …
Does second‐to‐fourth digit length ratio (2D
Prenatal steroid levels, estimated as the ratio of second‐to‐fourth digit length (2D:4D), have been related to reproductive success in women, but direct associations between 2D:4D and physiological measures of fertility remain rare. A recent study reported that lower, masculinized right hand 2D:4D was correlated with delayed age at menarche in women. We addressed this question by investigating whether 2D:4D was associated with recalled age at men…
Latitudinal Gradient in 2D
A tradeoff between reproduction and growth in contemporary Finnish women
Maternal 2nd to 4th digit ratio does not predict lifetime offspring sex ratio at birth
The low ratio of second‐to‐fourth digit length (2D:4D) of parents, a putative indicator of high prenatal and even adult testosterone levels, has been suggested to predict a male‐biased secondary offspring sex ratio. We investigated this question in 244 contemporary postreproductive Finnish women. Information on the lifetime offspring birth sex ratio of women was collected by questionnaires and the 2D:4D of both their hands were measured from scan…
Climatic variability and the population dynamics of historical hunter–gatherers
Our current knowledge on climate-mediated effects on human population dynamics is based on preindustrial agrarian societies where climate-induced crop failures had a major impact on fertility and mortality rates. However, because most of the human evolutionary history has been shaped by hunter-gatherer lifestyle relying on diverse plant and animal food sources, it is also important to understand how climate affected the population dynamics of hun…
Fitness benefits of prolonged post-reproductive lifespan in women
Latitudinal Gradient in 2D
Do "Dark" Personality Features Buffer Against Adversity? The Associations Between Cumulative Life Stress, the Dark Triad, and Mental Distress
Stressful life events have a major impact on adverse mental health outcomes, although not all individuals are equally affected. According to the buffering hypothesis, there may be personality traits that protect individuals against mental distress in the face of adversity, playing thus a moderating role between life stressors and mental distress. In the present online study ( N = 574), Dark Triad of personality (i.e., Machiavellianism, narcissism…
Sex of preceding sibling and anthropometrics of subsequent offspring at birth and in young adulthood
In many mammal species with sexual dimorphism producing sons is energetically more demanding to the mother than producing daughters. Although some studies in humans have suggested that offspring born after a brother have a smaller birth weight and adult height when compared with those born after a sister, little is known about this intergenerational cost of producing sons. We aimed to study whether the sex of preceding sibling is associated with …
Testing the expensive-tissue hypothesis’ prediction of inter-tissue competition using causal modelling with latent variables
The expensive-tissue hypothesis (ETH) posited a brain–gut trade-off to explain how humans evolved large, costly brains. Versions of the ETH interrogating gut or other body tissues have been tested in non-human animals, but not humans. We collected brain and body composition data in 70 South Asian women and used structural equation modelling with instrumental variables, an approach that handles threats to causal inference including measurement err…
Parental Investment by Birth Fathers and Stepfathers
This study investigates the determinants of paternal investment by birth fathers and stepfathers. Inclusive fitness theory predicts higher parental investment in birth children than stepchildren, and this has consistently been found in previous studies. Here we investigate whether paternal investment varies with childhood co-residence duration and differs between stepfathers and divorced birth fathers by comparing the investment of (1) stepfather…
Fitness benefits of prolonged post-reproductive lifespan in women
Climatic variability and the population dynamics of historical hunter–gatherers
Our current knowledge on climate-mediated effects on human population dynamics is based on preindustrial agrarian societies where climate-induced crop failures had a major impact on fertility and mortality rates. However, because most of the human evolutionary history has been shaped by hunter-gatherer lifestyle relying on diverse plant and animal food sources, it is also important to understand how climate affected the population dynamics of hun…
A tradeoff between reproduction and growth in contemporary Finnish women
Maternal 2nd to 4th digit ratio does not predict lifetime offspring sex ratio at birth
The low ratio of second‐to‐fourth digit length (2D:4D) of parents, a putative indicator of high prenatal and even adult testosterone levels, has been suggested to predict a male‐biased secondary offspring sex ratio. We investigated this question in 244 contemporary postreproductive Finnish women. Information on the lifetime offspring birth sex ratio of women was collected by questionnaires and the 2D:4D of both their hands were measured from scan…
Latitudinal Gradient in 2D
Does second‐to‐fourth digit length ratio (2D
Prenatal steroid levels, estimated as the ratio of second‐to‐fourth digit length (2D:4D), have been related to reproductive success in women, but direct associations between 2D:4D and physiological measures of fertility remain rare. A recent study reported that lower, masculinized right hand 2D:4D was correlated with delayed age at menarche in women. We addressed this question by investigating whether 2D:4D was associated with recalled age at men…
Sex of preceding sibling and anthropometrics of subsequent offspring at birth and in young adulthood
In many mammal species with sexual dimorphism producing sons is energetically more demanding to the mother than producing daughters. Although some studies in humans have suggested that offspring born after a brother have a smaller birth weight and adult height when compared with those born after a sister, little is known about this intergenerational cost of producing sons. We aimed to study whether the sex of preceding sibling is associated with …
Women's reproductive success and the preference for Dark Triad in men's faces
Accounting for measurement error in human life history trade‐offs using structural equation modeling
OBJECTIVES: Revealing causal effects from correlative data is very challenging and a contemporary problem in human life history research owing to the lack of experimental approach. Problems with causal inference arising from measurement error in independent variables, whether related either to inaccurate measurement technique or validity of measurements, seem not well-known in this field. The aim of this study is to show how structural equation m…
Do "Dark" Personality Features Buffer Against Adversity? The Associations Between Cumulative Life Stress, the Dark Triad, and Mental Distress
Stressful life events have a major impact on adverse mental health outcomes, although not all individuals are equally affected. According to the buffering hypothesis, there may be personality traits that protect individuals against mental distress in the face of adversity, playing thus a moderating role between life stressors and mental distress. In the present online study ( N = 574), Dark Triad of personality (i.e., Machiavellianism, narcissism…
Support for populist candidates predicted by declining social capital and an increase in suicides
Parental Investment by Birth Fathers and Stepfathers
This study investigates the determinants of paternal investment by birth fathers and stepfathers. Inclusive fitness theory predicts higher parental investment in birth children than stepchildren, and this has consistently been found in previous studies. Here we investigate whether paternal investment varies with childhood co-residence duration and differs between stepfathers and divorced birth fathers by comparing the investment of (1) stepfather…
Testing the expensive-tissue hypothesis’ prediction of inter-tissue competition using causal modelling with latent variables
The expensive-tissue hypothesis (ETH) posited a brain–gut trade-off to explain how humans evolved large, costly brains. Versions of the ETH interrogating gut or other body tissues have been tested in non-human animals, but not humans. We collected brain and body composition data in 70 South Asian women and used structural equation modelling with instrumental variables, an approach that handles threats to causal inference including measurement err…
Biology (8 works) · Demography (8 works) · Population (8 works) · Psychology (7 works) · Pregnancy (6 works) · Developmental psychology (5 works) · Evolutionary Psychology and Human Behavior (5 works) · Medicine (5 works) · Offspring (5 works) · Sexual Differentiation and Disorders (4 works)