W. Jake Jacobs

The evolutionary basis of risky adolescent behavior: implications for science, policy, and practice.

This article proposes an evolutionary model of risky behavior in adolescence and contrasts it with the prevailing developmental psychopathology model. The evolutionary model contends that understanding the evolutionary functions of adolescence is critical to explaining why adolescents engage in risky behavior and that successful intervention depends on working with, instead of against, adolescent goals and motivations. The current article articulates 5 key evolutionary insights into risky adolescent behavior: (a) The adolescent transition is an inflection point in development of social status and reproductive trajectories; (b) interventions need to address the adaptive functions of risky and aggressive behaviors like bullying; (c) risky adolescent behavior adaptively calibrates over development to match both harsh and unpredictable environmental conditions; (d) understanding evolved sex differences is critical for understanding the psychology of risky behavior; and (e) mismatches between current and past environments can dysregulate adolescent behavior, as demonstrated by age-segregated social groupings. The evolutionary model has broad implications for designing interventions for high-risk youth and suggests new directions for research that have not been forthcoming from other perspectives.

The impact of stress on neutral and emotional aspects of episodic memory

The present experiment demonstrates that exposure to a significant psychological stressor (administered before watching a slide show) preserves or even enhances memory for emotional aspects of an event, and simultaneously disrupts memory for non-emotional aspects of the same event. Stress exposure also disrupted memory for information that was visually and thematically central to the event depicted in the slide show. Memory for peripheral information, on the other hand, was unaffected by stress. These results are consistent with theories invoking differential effects of stress on brain systems responsible for encoding and retrieving emotional memories (the amygdala) and non-emotional memories (e.g., the hippocampal formation), and inconsistent with the view that memories formed under high levels of stress are qualitatively the same as those formed under ordinary emotional circumstances. These data, which are also consistent with results obtained in a number of studies using animals and humans, have implications for the traumatic memory debate and theories regarding human memory.

Stress Differentially Modulates Fear Conditioning in Healthy Men and Women

BACKGROUND Stress and stress hormones modulate emotional learning in rats and might have similar effects in humans. Theoretic accounts of posttraumatic stress disorder (PTSD), for example, implicate the stress-induced modulation of fear conditioning in the development of intrusive emotional reactions. The present study examined the impact of acute stress and cortisol (CORT) on classically conditioned fear in men and women. METHODS Ninety-four healthy undergraduates were exposed to a mild stressor (or control condition) while subjective anxiety and glucocorticoid stress responses (salivary CORT) were measured. One hour later, all participants participated in a differential fear conditioning procedure while conditioned skin conductance responses (SCR) were recorded. RESULTS Exposure to the stressor increased subjective anxiety and elevated CORT levels. In men, stress exposure facilitated fear conditioning; whereas in women, stress appeared to inhibit fear conditioning. The impact of stress on differential conditioning in men was associated with increased CORT levels. CONCLUSIONS Consistent with animal models, these results demonstrate that stress exposure can modulate classical conditioning in humans, possibly via hormonal mechanisms. The enhancing effects of stress on the formation of conditioned fear might provide a useful model for the formation of pathological emotional reactions, such as those found in PTSD.

Mindfulness-Based Cognitive Therapy Improves Emotional Reactivity to Social Stress: Results from a Randomized Controlled Trial ☆

The high likelihood of recurrence in depression is linked to a progressive increase in emotional reactivity to stress (stress sensitization). Mindfulness-based therapies teach mindfulness skills designed to decrease emotional reactivity in the face of negative affect-producing stressors. The primary aim of the current study was to assess whether Mindfulness-Based Cognitive Therapy (MBCT) is efficacious in reducing emotional reactivity to social evaluative threat in a clinical sample with recurrent depression. A secondary aim was to assess whether improvement in emotional reactivity mediates improvements in depressive symptoms. Fifty-two individuals with partially remitted depression were randomized into an 8-week MBCT course or a waitlist control condition. All participants underwent the Trier Social Stress Test (TSST) before and after the 8-week trial period. Emotional reactivity to stress was assessed with the Spielberger State Anxiety Inventory at several time points before, during, and after the stressor. MBCT was associated with decreased emotional reactivity to social stress, specifically during the recovery (post-stressor) phase of the TSST. Waitlist controls showed an increase in anticipatory (pre-stressor) anxiety that was absent in the MBCT group. Improvements in emotional reactivity partially mediated improvements in depressive symptoms. Limitations include small sample size, lack of objective or treatment adherence measures, and non-generalizability to more severely depressed populations. Given that emotional reactivity to stress is an important psychopathological process underlying the chronic and recurrent nature of depression, these findings suggest that mindfulness skills are important in adaptive emotion regulation when coping with stress.

Self, friends, and lovers: structural relations among Beck Depression Inventory scores and perceived mate values

BACKGROUND We used an economic model based on evolutionary theory to guide an examination of relations among self-reported depressive symptoms and ratings of mate values of self, social, and sexual partners. This model treats assortative mating as a form of social exchange between partners of socially and sexually desirable traits. METHODS Two studies used variants of the Mate Value Inventory (MVI), a multivariate assessment of attributes desired in social or sexual partners. For study 1, 115 male and 124 female undergraduates provided self reports on four forms of the MVI-11 and on the Beck Depression Inventory (BDI); for study 2, 208 male and 277 female undergraduates provided self reports on seven forms of the MVI-7 and on the BDI-II. RESULTS Both multisample structural equations models indicated that the parameters were statistically equivalent between female and male subsamples and provided an adequate fit to the data. The models revealed significant relations between the mate values ascribed to the self and those ascribed to short- and long-term partners as well as best friends. Furthermore, greater BDI scores significantly predicted lesser ratings of mate value for the self, and hence indirectly predicted lesser ratings of mate value for all types of partners evaluated. LIMITATIONS Although the data obtained from the MVI demonstrated good psychometric validity, external validity has not yet been established. CONCLUSIONS The results are consistent with models predicting: (1) assortative mating by mate value, (2) differential exchange rates of mate value for different types of partners, (3) a negative relation between depressive symptoms and assessment of ones own mate value, and (4) a possibly consequential mismatch of mate values when one partner exhibits or recovers from significant depressive symptoms. The results are inconsistent with models predicting (5) a generalized negativity bias due to depression.

Evolutionary Personality Psychology

Multiple selective pressures maintain and increase heritable behavioral variability among individuals across both developmental and evolutionary time: (1) directional social selection favors convergent traits, promoting mutually beneficial cooperative interactions; (2) disruptive social selection favors divergent traits, providing release from within-species competition; (3) genetic diversification responds adaptively to the stochastic (random) characteristics of environmental hazards such as uncontrollable morbidity (disease) and mortality (death); (4) developmental plasticity epigenetically directs development adaptively along different alternative pathways, modifying permanent and stable behavioral dispositions to suit long-term contingencies of survival and reproduction; and (5) behavioral flexibility deploys rapid and reversible short-term adaptive behavioral responses to transient situations.

Moral intuitions and religiosity as spuriously correlated life history traits

Religions promote moral rules of behavior and religiosity is associated with some types of moral intuitions, but there is no ultimate-level explanation for this association. Religiosity has recently been used as an indicator of a multivariate measure of slow Life History (LH) strategy. In this study, we predicted that LH strategy relates to increased strength of moral intuitions as meas- ured by morally dumbfounding intuitions, reactions to violations of the ethics of autonomy, com- munity, and divinity, and disgust sensitivity. Results of an exploratory factor analysis revealed that a 3-factor solution was optimal: (1) Religiosity (2) Moral Intuitions, (3) LH strategy. Com- parisons of three path-analytic structural models indicated that only one model had an acceptable fit. In that model, slow LH strategy directly influenced religiosity and moral intuitions, which were, as a result, spuriously correlated. We discuss implications for LH theory and for the relation between religion and moral intuitions.

Place learning in virtual space. III: Investigation of spatial navigation training procedures and their application to fMRI and clinical neuropsychology.

This paper describes the utilization of a desktop virtual environment task, the Computer-Generated (C-G) Arena, in the study of human spatial navigation. First, four experiments examined the efficacy of various training procedures in the C-G Arena. In Experiment 1, participants efficiently located a hidden target after only observing the virtual environment from a fixed position (placement learning). In Experiment 2, participants efficiently located a hidden target after only observing an experimenter search the virtual environment (observational learning). In Experiment 3, participants failed to display alatent learning effect in the virtual environment. In Experiment 4, all training procedures effectively taught participants the layout of the virtual environment, but the observational learning procedure most effectivelytaught participants the location of a hidden target within the environment. Finally, two experiments demonstrated the application of C-G Arena procedures to neuroimaging (Experiment 5) and neuropsychological (Experiment 6) investigations of human spatial navigation.

Maturation of Spatial Navigation Strategies: Convergent Findings from Computerized Spatial Environments and Self-Report

Using 2 computerized spatial navigation tasks, we examined the development of cue and place learning in children ages 3 to 10 years, comparing their data to adults. We also examined relations between place learning in computerized and real space. Results showed children use the 2-dimensional space as if it were real space. Results also demonstrated that children ages 3 to 10 years cue learn (locating a visible target) but do not show evidence of mature place learning (locating an invisible target) until around age 10 years. Self-report data indicated an age-related increase in use of relations among distal cues during place learning. Children ages 3 to 4 years did not report using distal cues; most 9- to 10-year-old children reported using multiple distal cues to guide their search during place learning. Results suggest that, as maturation proceeds, children make increasing use of relations among multiple distal cues to guide a search for places in space.

Age-related changes in a human cognitive mapping system: data from a computer-generated environment.

Two studies investigated age-related changes in human spatial cognition. In Study 1, younger and older adults searched computer-generated space, over several trials, for the location of a hidden target. Younger adults, but not older adults, quickly located the target and consistently returned to it. All the younger adults, but few of the older adults, reported using spatial relations among distal cues to navigate the space. In Study 2, young, middle-aged, and older adults performed the same task, but were provided with increased environmental support and pre-task training. The data pattern from Study 1 was replicated, with the performance of middle-aged adults falling between that of young and older adults. Although older adults in Study 2 reported less experience at completing computer-based tasks than did young and middle-aged adults, effects of this differential level of computer experience appeared to diminish over the course of experimental procedures (i.e., group differences that appeared on pre-task non-spatial practice trials were not apparent on a similar post-task trial). Age-related differences in spatial cognition persisted, however. Thus, the current data (a) suggest that a human cognitive mapping system changes over the lifespan, (b) suggest that computer-generated tasks can be sensitive to those changes, and (c) are consistent with a substantial literature investigating age-related changes in human and rodent spatial cognition.