scholarly journals The evolution of sensitive periods in a model of incremental development

2016 ◽  
Vol 283 (1823) ◽  
pp. 20152439 ◽  
Author(s):  
Karthik Panchanathan ◽  
Willem E. Frankenhuis
Keyword(s):  
Developmental Trajectories ◽  
Life Stage ◽  
Model Development ◽  
Later Life ◽  
Evolutionary Selection ◽  
Incremental Development ◽  
Sensitive Periods ◽  
Physiological Explanation ◽  
Lagged Effects ◽  
Phenotypic Development

Sensitive periods, in which experience shapes phenotypic development to a larger extent than other periods, are widespread in nature. Despite a recent focus on neural–physiological explanation, few formal models have examined the evolutionary selection pressures that result in developmental mechanisms that produce sensitive periods. Here, we present such a model. We model development as a specialization process during which individuals incrementally adapt to local environmental conditions, while receiving a constant stream of cost-free, imperfect cues to the environmental state. We compute optimal developmental programmes across a range of ecological conditions and use these programmes to simulate developmental trajectories and obtain distributions of mature phenotypes. We highlight four main results. First, matching the empirical record, sensitive periods often result from experience or from a combination of age and experience, but rarely from age alone. Second, individual differences in sensitive periods emerge as a result of stochasticity in cues: individuals who obtain more consistent cue sets lose their plasticity at faster rates. Third, in some cases, experience shapes phenotypes only at a later life stage (lagged effects). Fourth, individuals might perseverate along developmental trajectories despite accumulating evidence suggesting the alternate trajectory is more likely to match the ecology.

scholarly journals VITAL INVOLVEMENT: A SOURCE OF REALISTIC OPTIMISM FOR OLDER ADULTHOOD

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S407-S408
Author(s):  
Helen Q Kivnick
Keyword(s):  
Psychosocial Development ◽  
Life Stage ◽  
Later Life ◽  
Older Adulthood ◽  
Environmental Engagement ◽  
The World ◽  
Psychosocial Model

Abstract Vital Involvement (VI) was initially proposed (Erikson et al., 1986) as one of three principles around which lifelong healthy psychosocial development takes place. As more recently elaborated, VI has come to describe a person’s meaningful, reciprocal engagement with the world outside the integrating “self.” It is through VI that the person engages in healthy psychosocial development throughout life, including balancing Older Adulthood’s focal tension between Integrity and Despair. This life stage is widely associated with the physical, cognitive, and social losses, and societal constraints that give rise to later-life despair. However, VI functions as a lifelong psychosocial model for the meaningful environmental engagement that supports later life’s wisdom and integrity. Notably few films present an integrated view of older adulthood’s losses along with opportunities. But those few can be a source of optimism to elders for whom VI may not be intuitive, but who can learn its practice.

scholarly journals Adult life stage and crisis as predictors of curiosity and authenticity

2016 ◽  
Vol 41 (3) ◽  
pp. 426-431 ◽  
Author(s):  
Oliver C. Robinson ◽  
James D. Demetre ◽  
Jordan A. Litman
Keyword(s):  
Life Stage ◽  
Adult Life ◽  
Later Life ◽  
Self Report ◽  
Self Help ◽  
Felt Sense ◽  
Quasi Experimental ◽  
Report Data ◽  
Nationally Representative ◽  
Self Report Data

During periods of developmental crisis, individuals experience uncomfortable internal incongruence and are motivated to reduce this through forms of exploration of self, other and world. Based on this, we inferred that being in a crisis would relate positively to curiosity and negatively to a felt sense of authenticity. A quasi-experimental design using self-report data from a nationally representative UK sample ( N = 963) of adults in early life (20–39 years), midlife (40–59 years) and later-life (60+) showed a pattern of findings supportive of the hypotheses. Three forms of curiosity (intrapersonal, perceptual and epistemic D-type) were significantly higher, while authenticity was lower, among those currently in crisis that those of the same age group not in crisis. Crisis was also related to curiosity about particular book genres; early adult crisis to self-help and spirituality, midlife to self-help and biography, and later life to food and eating.

scholarly journals Negative Density Dependence Regulates Two Tree Species at Later Life Stage in a Temperate Forest

PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e103344 ◽  
Author(s):  
Tiefeng Piao ◽  
Jung Hwa Chun ◽  
Hee Moon Yang ◽  
Kwangil Cheon
Keyword(s):  
Density Dependence ◽  
Tree Species ◽  
Temperate Forest ◽  
Life Stage ◽  
Later Life ◽  
Negative Density Dependence

Longitudinal associations of hopelessness and loneliness in older adults: results from the US health and retirement study

2017 ◽  
Vol 29 (9) ◽  
pp. 1451-1459 ◽  
Author(s):  
Amber M. Gum ◽  
Sharon Shiovitz-Ezra ◽  
Liat Ayalon
Keyword(s):  
Later Life ◽  
Health And Retirement Study ◽  
Small Magnitude ◽  
Simultaneous Evaluation ◽  
The Us ◽  
Lagged Effects ◽  
The Stability ◽  
Time Frames ◽  
Retirement Study ◽  
Lagged Effect

ABSTRACTBackground:Hopelessness and loneliness are potent risk factors for poor mental and physical health in later life, although the nature of their relationships with each other over time is not clear. The aim of the current study was to examine relationships between hopelessness and loneliness over an eight-year study period.Methods:Three waves of data from the US Health and Retirement Study (2006, 2010, 2014) were used to test a cross-lagged model of hopelessness and loneliness (N= 7,831), which allows for the simultaneous evaluation of the reciprocal associations of loneliness and hopelessness. Age in 2006, gender, years of education, number of medical conditions, and depressive symptoms were included as covariates.Results:The autoregressive effects of loneliness (B(SE) = 0.63 (0.02),p< 0.001) and hopelessness (B(SE) = 0.63 (0.02),p< 0.001) were substantive and significant across the three waves, pointing to the stability of both constructs over the eight-year study period. The lagged effect of loneliness on hopelessness was non-significant (B(SE) = 0.05 (0.03),p= 0.16), whereas the lagged effect of hopelessness on loneliness was significant (B(SE) = 0.01 (0.01),p= 0.03). These lagged effects were not significantly different from each other, however, χ2(1) = 2.016,p= 0.156.Conclusions:Participants who were more hopeless tended to become lonelier four years later, but lonelier participants did not become more hopeless four years later. Findings are tentative given the small magnitude and lack of difference between the cross-lagged effects. Future directions include replicating these findings in different samples and time frames, examining potential mechanisms of relationships between hopelessness and loneliness, and potential intervention strategies that might improve both conditions.

scholarly journals No evidence of spatial representation of age, but “own-age bias” like face processing found in chimpanzees

2021 ◽  
Author(s):  
Yuri Kawaguchi ◽  
Masaki Tomonaga ◽  
Ikuma Adachi
Keyword(s):  
Response Time ◽  
Face Processing ◽  
Spatial Representation ◽  
Life Stage ◽  
Later Life ◽  
Processing Efficiency ◽  
Age Bias ◽  
Conspecific Adult ◽  
Infant Faces ◽  
Age Category

AbstractPrevious studies have revealed that non-human primates can differentiate the age category of faces. However, the knowledge about age recognition in non-human primates is very limited and whether non-human primates can process facial age information in a similar way to humans is unknown. As humans have an association between time and space (e.g., a person in an earlier life stage to the left and a person in a later life stage to the right), we investigated whether chimpanzees spatially represent conspecifics’ adult and infant faces. Chimpanzees were tested using an identical matching-to-sample task with conspecific adult and infant face stimuli. Two comparison images were presented vertically (Experiment 1) or horizontally (Experiment 2). We analyzed whether the response time was influenced by the position and age category of the target stimuli, but there was no evidence of correspondence between space and adult/infant faces. Thus, evidence of the spatial representation of the age category was not found. However, we did find that the response time was consistently faster when they discriminated between adult faces than when they discriminated between infant faces in both experiments. This result is in line with a series of human face studies that suggest the existence of an “own-age bias.” As far as we know, this is the first report of asymmetric face processing efficiency between infant and adult faces in non-human primates.

scholarly journals Trajectories of Mother-Infant Communication: An Experiential Measure of the Impacts of Early Life Adversity

2021 ◽  
Vol 15 ◽  
Author(s):  
Lauren Granata ◽  
Alissa Valentine ◽  
Jason L. Hirsch ◽  
Jennifer Honeycutt ◽  
Heather Brenhouse
Keyword(s):  
Maternal Care ◽  
Early Life ◽  
Maternal Separation ◽  
Developmental Trajectories ◽  
Later Life ◽  
Developmental Trajectory ◽  
Acoustic Properties ◽  
Emission Rates ◽  
Acoustic Parameters ◽  
Early Life Adversity

Caretaking stability in the early life environment supports neurobehavioral development, while instability and neglect constitute adverse environments that can alter maturational processes. Research in humans suggests that different types of early life adversity (ELA) can have differential effects on caretaker relationships and later cognitive and social development; however, identifying mechanistic underpinnings will require animal models with translational validity. Two common rodent models, maternal separation (MS) and limited bedding (LB), influence the mother-infant relationship during a critical window of development. We hypothesized that these paradigms may affect the development of communication strategies on the part of the pup. Ultrasonic vocalizations (USVs) are a care-eliciting mechanism and ethologically relevant response to stressors in the rat pup. USV emission rates and acoustic parameters change throughout early development, presenting the opportunity to define developmental milestones in USVs that would reflect neurobehavioral aberrations if disrupted. This study investigated the effects of MS or LB on the dam-pup relationship by quantifying pup USVs, maternal behavior, and the relationship between the two. First, we used a generalized additive model approach to establish typical developmental trajectories of USV acoustic properties and determine windows of change in MS or LB rearing. Additionally, we quantified maternal behaviors and the predictability of maternal care sequences using an entropy rate calculation. MS and LB each shifted the developmental trajectories of USV acoustic parameters and call types in a sex-specific manner. MS more often impacted male USVs, while LB impacted female USVs. MS dams spent more time passive nursing, and LB dams spent more time on the nest. The predictability of maternal care was associated with the rate of USV emissions exclusively in females. Taken together, findings demonstrate sex- and model-specific effects of rearing environments on a novel developmental trajectory involving the mother-infant relationship, facilitating the translation of animal ELA paradigms to assess later-life consequences.

Life satisfaction in older adults in Spain: beyond subjective health

2019 ◽  
Vol 31 (2) ◽  
pp. 167-168 ◽  
Author(s):  
Mark Rapoport
Keyword(s):  
Successful Aging ◽  
Life Stage ◽  
Later Life ◽  
Subjective Health ◽  
Negative Stereotypes ◽  
Successful Resolution ◽  
The Common ◽  
Disengagement Theory ◽  
Life Roles

Many authors over the centuries have attempted to refute popular negative stereotypes about aging. In 2010, Depp, Vahia, and Jeste reviewed theories of success in aging (Depp et al., 2010), and some examples include Erikson's life stage theory in which he posited that successful resolution of earlier conflicts led to integrity in later life instead of despair; disengagement theory referred to the fact that in our culture, aging is associated with social isolation and reduced societal involvement – with this theory, successful adaptation to aging means coping with this normative disengagement in a healthy manner; activity theory referred to continued engagement in later life; continuity theory emphasized the role of adapting oneself to maintain consistency with earlier life roles. The common theme is that longevity is not enough, and a successful aging process means delaying the onset of disability, compressing morbidity, or shortening the proportion of the lifespan in which one is disabled.

Ending Midlife Bias

2020 ◽  
Author(s):  
Nancy S. Jecker
Keyword(s):  
Migrant Workers ◽  
Population Aging ◽  
Life Stage ◽  
Early Adulthood ◽  
Later Life ◽  
Mandatory Retirement ◽  
Human Capabilities ◽  
Pediatric Bioethics

We live at a time when human lifespans have increased like never before. As average lifespans stretch to new lengths, how does this impact the values we hold most dear? Do these values change over the course of our ever-increasing lifespans? Ending Midlife Bias argues that at different life stages, different values emerge as central. During early life, caring and trust matter more, given human vulnerability and dependency. By early adulthood, growing independence provides a reason to value autonomy more. Later in life, heightened risk for chronic disease and disability warrants focusing on maintaining capabilities and keeping dignity intact. Part I (Chapters 1–5) sets forth a conceptual framework that captures these shifting life stage values. Chapter 1 argues against the privileging of midlife values (midlife bias) and explains why population aging lends urgency to identifying values for later life. Chapters 2 and 3 introduce dignity as a central concern for older adults and argue that respecting dignity requires supporting central human capabilities. Chapter 4 explores the metaphor of life as a story, which serves as a corrective for midlife bias by keeping attention on the whole of life. Chapter 5 sets forth principles for age group justice. Part II (Chapters 6–12) turns to practical concerns, including geriatric and pediatric bioethics (Chapter 6); caregiving by family members, migrant workers, and robots (Chapters 7 and 8); ageism in clinical trials, healthcare allocation, and mandatory retirement (Chapter 9); and ethics at the end-of-life (Chapter 10). The closing chapters explore the future of population aging (Chapter 11) and make a pitch for life stage sensitive moral theory (Chapter 12).

scholarly journals Balancing sampling and specialization: an adaptationist model of incremental development

2011 ◽  
Vol 278 (1724) ◽  
pp. 3558-3565 ◽  
Author(s):  
Willem E. Frankenhuis ◽  
Karthik Panchanathan
Keyword(s):  
Natural Selection ◽  
Evolutionary Ecology ◽  
Developmental Systems ◽  
Stochastic Sampling ◽  
Incremental Development ◽  
Developmental Mechanisms ◽  
Constructive Process ◽  
Developmental Programme ◽  
Novel Model ◽  
Phenotypic Development

Development is typically a constructive process, in which phenotypes incrementally adapt to local ecologies. Here, we present a novel model in which natural selection shapes developmental systems based on the evolutionary ecology, and these systems adaptively guide phenotypic development. We assume that phenotypic construction is incremental and trades off with sampling cues to the environmental state. We computed the optimal developmental programmes across a range of evolutionary ecological conditions. Using these programmes, we simulated distributions of mature phenotypes. Our results show that organisms sample the environment most extensively when cues are moderately, not highly, informative. When the developmental programme relies heavily on sampling, individuals transition from sampling to specialization at different times in ontogeny, depending on the consistency of their sampled cue set; this finding suggests that stochastic sampling may result in individual differences in plasticity itself. In addition, we find that different selection pressures may favour similar developmental mechanisms, and that organisms may incorrectly calibrate development despite stable ontogenetic environments. We hope our model will stimulate adaptationist research on the constructive processes guiding development.

scholarly journals Direct and indirect climate forcing in a multi-species marine system

2010 ◽  
Vol 277 (1699) ◽  
pp. 3411-3420 ◽  
Author(s):  
Leif Christian Stige ◽  
Geir Ottersen ◽  
Padmini Dalpadado ◽  
Kung-Sik Chan ◽  
Dag Ø. Hjermann ◽  
...  
Keyword(s):  
Barents Sea ◽  
Time Series Data ◽  
Life Stage ◽  
Later Life ◽  
Zooplankton Biomass ◽  
Climate Impacts ◽  
Series Data ◽  
Life Stages ◽  
Growth And Survival ◽  
Climate Effects

Interactions within and between species complicate quantification of climate effects, by causing indirect, often delayed, effects of climate fluctuations and compensation of mortality. Here we identify direct and indirect climate effects by analysing unique Russian time-series data from the Norwegian Sea–Barents Sea ecosystem on the first life stages of cod, capelin, herring and haddock, their predators, competitors and zooplanktonic prey. By analysing growth and survival from one life stage to the next (eggs–larvae–juveniles–recruits), we find evidence for both bottom-up, direct and top-down effects of climate. Ambient zooplankton biomass predicts survival of all species, whereas ambient temperature mainly affects survival through effects on growth. In warm years, all species experienced improved growth and feeding conditions. Cohorts born following a warm year will, however, experience increased predation and competition because of increased densities of subadult cod and herring, leading to delayed climate effects. While climate thus affects early growth and survival through several mechanisms, only some of the identified mechanisms were found to be significant predictors of population growth. In particular, our findings exemplify that climate impacts are barely propagated to later life stages when density dependence is strong.

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