The threat simulation theory of the evolutionary function of dreaming: Evidence from dreams of traumatized children

The threat simulation theory of dreaming (TST) () states that dream consciousness is essentially an ancient biological defence mechanism, evolutionarily selected for its capacity to repeatedly simulate threatening events. Threat simulation during dreaming rehearses the cognitive mechanisms required for efficient threat perception and threat avoidance, leading to increased probability of reproductive success during human evolution. One hypothesis drawn from TST is that real threatening events encountered by the individual during wakefulness should lead to an increased activation of the system, a threat simulation response, and therefore, to an increased frequency and severity of threatening events in dreams. Consequently, children who live in an environment in which their physical and psychological well-being is constantly threatened should have a highly activated dream production and threat simulation system, whereas children living in a safe environment that is relatively free of such threat cues should have a weakly activated system. We tested this hypothesis by analysing the content of dream reports from severely traumatized and less traumatized Kurdish children and ordinary, non-traumatized Finnish children. Our results give support for most of the predictions drawn from TST. The severely traumatized children reported a significantly greater number of dreams and their dreams included a higher number of threatening dream events. The dream threats of traumatized children were also more severe in nature than the threats of less traumatized or non-traumatized children.     

Gender differences in social cognitive determinants of exercise adoption

Gender differences in lifestyle-related mortality and morbidity suggest a need to investigate gender-specificity of health behaviour change process and factors influencing it. We tested whether changes in self-efficacy beliefs and planning, as well as the level of social support predict change in exercise. Finnish men and women, aged 50–65 years, at an increased risk for type 2 diabetes were recruited from health care centres to participate in the Good Ageing in Lahti Region (GOAL) Lifestyle Implementation Trial. Psychosocial factors were measured with questionnaires and exercise with 7-day physical activity diaries at baseline and at 3 months. At baseline, no gender differences were found in self-efficacy and planning, but men reported receiving more social support than women. At 3 months, women reported having formed more action plans for changing their exercise routines than men. Among women, increase in self-efficacy and planning predicted increase in exercise. Among men, changes in planning played a less significant role. The more salient role of planning for women than for men, and the fact that women receive less social support, may reflect life circumstances allowing less spontaneous lifestyle decisions and a lower acceptance of lifestyle changes by their social environment.     

Grandparental child care in Europe: Evidence for preferential investment in more certain kin

Theories of kin selection and parental investment predict stronger investment in children and grandchildren by women and maternal kin. Due to paternity uncertainty, parental and grandparental investments along paternal lineages are based on less certain genetic relatedness with the children and grandchildren. Additionally, the hypothesis of preferential investment (Laham, Gonsalkorale, and von Hippel, 2005) predicts investment to vary according to available investment options. Two previous studies have tested this hypothesis with small samples and conflicting results. Using the second wave of the large and multinational Survey of Health, Ageing and Retirement in Europe (SHARE), collected in 2006-07, we study the preferential investment hypothesis in contemporary Europe based on self-reported grandparental provision of child care. We predict that 1) maternal grandmothers provide most care for their grandchildren, followed by maternal grandfathers, paternal grandmothers and last by paternal grandfathers; 2) maternal grandfathers and paternal grandmothers provide equal amounts of care when the latter do not have grandchildren via a daughter; 3) women who have grandchildren via both a daughter and a son will look after the children of the daughter more; and 4) men who have grandchildren via both a daughter and a son will look after the children of the daughter more. Results support all four hypotheses and provide evidence for the continuing effects of paternity uncertainty in contemporary kin behavior.     

Literacy skills seem to fuel literacy enjoyment,rather than vice versa

Children who like to read and write tend to be better at it. This association is typically interpreted as enjoyment impacting engagement in literacy activities, which boosts literacy skills. We fitted direction-of-causation models to partial data of 3690 Finnish twins aged 12. Literacy skills were rated by the twins’ teachers and literacy enjoyment by the twins themselves. A bivariate twin model showed substantial genetic influences on literacy skills (70%) and literacy enjoyment (35%). In both skills and enjoyment, shared-environmental influences explained about 20% in each. The best-fitting direction-of-causation model showed that skills impacted enjoyment, while the influence in the other direction was zero. The genetic influences on skills influenced enjoyment, likely via the skills→enjoyment path. This indicates an active gene-environment correlation: children with an aptitude for good literacy skills are more likely to enjoy reading and seek out literacy activities. To a lesser extent, it was also the shared-environmental influences on children's skills that propagated to influence children's literacy enjoyment. Environmental influences that foster children's literacy skills (e.g., families and schools), also foster children's love for reading and writing. These findings underline the importance of nurturing children's literacy skills.

Highlights

• It's known that how much children enjoy reading and writing and how good they are at it correlates ∼0.30, but causality remains unknown.
• We tested the direction of causation in 3690 twins aged 12.
• Literacy skills impacted literacy enjoyment, but not the other way around.
• Genetics influence children's literacy skills and how much they like and choose to read and write, indicating genetic niche picking.

     

Listen-and-repeat training in the learning of non-native consonant duration contrasts: influence of consonant type as reflected by MMN and behavioral methods

Journal of Psycholinguistic Research - Phonological duration differences in quantity languages can be problematic for second language learners whose native language does not use duration...