Why Go There? Evolution of Mobility and Spatial Cognition in Women and Men : An Introduction to the Special Issue

Still little evidence sex differences in spatial navigation are evolutionary adaptations

A putative male advantage in wayfinding ability is the most widely documented sex difference in human cognition and has also been observed in other animals. The common interpretation, the sex-specific adaptation hypothesis, posits that this male advantage evolved as an adaptive response to sex differences in home range size. A previous study a decade ago tested this hypothesis by comparing sex differences in home range size and spatial ability among 11 species and found no relationship. However, the study was limited by the small sample size, the lack of species with a larger female home range and the lack of non-Western human data. The present study represents an update that addresses all of these limitations, including data from 10 more species and from human subsistence cultures. Consistent with the previous result, we found little evidence that sex differences in spatial navigation and home range size are related. We conclude that sex differences in spatial ability are more likely due to experiential factors and/or unselected biological side effects, rather than functional outcomes of natural selection.

Selection and adaptation in human migration

This article reviews the ways migration shapes human biology. This includes the physiological and genetic, but also socio-cultural aspects such as organization, behavior, and culture. Across disciplines I highlight the multiple levels of cultural and genetic selection whereby individuals and groups adapt to pressures along a migration timeline: the origin, transit, and destination. Generally, the evidence suggests that selective pressures and adaptations occur at the individual, family, and community levels. Consequently, across levels there are negotiations, interactions, and feedbacks that shape migration outcomes and the trajectory of evolutionary change. The rise and persistence of migration-relevant adaptations emerges as a central question, including the maintenance of cumulative culture adaptations, the persistence of "cultures of migration," as well as the individual-level physiological and cognitive adaptations applied to successful transit and settlement in novel environments.

Exploratory preferences explain the human fascination for imaginary worlds in fictional stories

Imaginary worlds are present and often central in many of the most culturally successful modern narrative fictions, be it in novels (e.g., Harry Potter), movies (e.g., Star Wars), video games (e.g., The Legend of Zelda), graphic novels (e.g., One Piece) and TV series (e.g., Game of Thrones). We propose that imaginary worlds are popular because they activate exploratory preferences that evolved to help us navigate the real world and find new fitness-relevant information. Therefore, we hypothesize that the attraction to imaginary worlds is intrinsically linked to the desire to explore novel environments and that both are influenced by the same underlying factors. Notably, the inter-individual and cross-cultural variability of the preference for imaginary worlds should follow the inter-individual and cross-cultural variability of exploratory preferences (with the personality trait Openness-to-experience, age, sex, and ecological conditions). We test these predictions with both experimental and computational methods. For experimental tests, we run a pre-registered online experiment about movie preferences (N = 230). For computational tests, we leverage two large cultural datasets, namely the Internet Movie Database (N = 9424 movies) and the Movie Personality Dataset (N = 3.5 million participants), and use machine-learning algorithms (i.e., random forest and topic modeling). In all, consistent with how the human preference for spatial exploration adaptively varies, we provide empirical evidence that imaginary worlds appeal more to more explorative people, people higher in Openness-to-experience, younger individuals, males, and individuals living in more affluent environments. We discuss the implications of these findings for our understanding of the cultural evolution of narrative fiction and, more broadly, the evolution of human exploratory preferences.

Navigational Experience and the Preservation of Spatial Abilities into Old Age Among a Tropical Forager-Farmer Population

Navigational performance responds to navigational challenges, and both decline with age in Western populations as older people become less mobile. But mobility does not decline everywhere; Tsimané forager-farmers in Bolivia remain highly mobile throughout adulthood, traveling frequently by foot and dugout canoe for subsistence and social visitation. We, therefore, measured both natural mobility and navigational performance in 305 Tsimané adults, to assess differences with age and to test whether greater mobility was related to better navigational performance across the lifespan. Daily mobility was measured by GPS tracking, regional mobility through interview, navigational performance through pointing accuracy and perspective taking in environmental space, and mental rotation by a computerized task. Although mental rotation and spatial perspective taking declined with age, mobility and pointing accuracy remained high from mid-life through old age. Greater regional mobility was associated with greater accuracy at pointing and perspective taking, suggesting that spatial experience at environmental scales may help maintain navigational performance in later adulthood.

Importance of Path Planning Variability: A Simulation Study

Individuals vary in the way they navigate through space. Some take novel shortcuts, while others rely on known routes to find their way around. We wondered how and why there is so much variation in the population. To address this, we first compared the trajectories of 368 human subjects navigating a virtual maze with simulated trajectories. The simulated trajectories were generated by strategy-based path planning algorithms from robotics. Based on the similarities between human trajectories and different strategy-based simulated trajectories, we found that there is a variation in the type of strategy individuals apply to navigate space, as well as variation within individuals on a trial-by-trial basis. Moreover, we observed variation within a trial when subjects occasionally switched the navigation strategies halfway through a trajectory. In these cases, subjects started with a route strategy, in which they followed a familiar path, and then switched to a survey strategy, in which they took shortcuts by considering the layout of the environment. Then we simulated a second set of trajectories using five different but comparable artificial maps. These trajectories produced the similar pattern of strategy variation within and between trials. Furthermore, we varied the relative cost, that is, the assumed mental effort or required timesteps to choose a learned route over alternative paths. When the learned route was relatively costly, the simulated agents tended to take shortcuts. Conversely, when the learned route was less costly, the simulated agents showed preference toward a route strategy. We suggest that cost or assumed mental effort may be the reason why in previous studies, subjects used survey knowledge when instructed to take the shortest path. We suggest that this variation we observe in humans may be beneficial for robotic swarms or collections of autonomous agents during information gathering.

Imaginary worlds are attractive because they simulate multiple adaptive problems and encode real-world information

Organisms don't explore for exploration's sake: exploratory psychology is regulated by inputs from multiple adaptations dedicated to processing information from different domains of ancestral adaptive relevance. As holistic representations of environments, imaginary worlds simulate multiple adaptive problems, solutions, and outcomes, thereby engaging numerous emotional systems and providing potentially useful information. Their popularity is thus best understood in terms of the full spectrum of information domains they comprise.

Cultural Change Reduces Gender Differences in Mobility and Spatial Ability among Seminomadic Pastoralist-Forager Children in Northern Namibia

A fundamental cognitive function found across a wide range of species and necessary for survival is the ability to navigate complex environments. It has been suggested that mobility may play an important role in the development of spatial skills. Despite evolutionary arguments offering logical explanations for why sex/gender differences in spatial abilities and mobility might exist, thus far there has been limited sampling from nonindustrialized and subsistence-based societies. This lack of sampling diversity has left many unanswered questions regarding the effects that environmental variation and cultural norms may have in shaping mobility patterns during childhood and the development of spatial competencies that may be associated with it. Here we examine variation in mobility (through GPS tracking and interviews), performance on large-scale spatial skills (i.e., navigational ability), and performance on small-scale spatial skills (e.g., mental rotation task, Corsi blocks task, and water-level task) among Twa forager/pastoralist children whose daily lives have been dramatically altered since settlement and the introduction of government-funded boarding schools. Unlike in previous findings among Twa adults, boys and girls (N = 88; aged 6-18) show similar patterns of travel on all measures of mobility. We also find no significant differences in spatial task performance by gender for large- or small-scale spatial skills. Further, children performed as well as adults did on mental rotation, and they outperformed adults on the water-level task. We discuss how children's early learning environments may influence the development of both large- and small-scale spatial skills.

Spatial and Social Behavior of Single and Coupled Individuals of Both Sexes during COVID-19 Lockdown Regime in Russia

Testing individual motivations for social activity in violation of the mandated lockdown regime is a challenging research topic for evolutionary psychology. To this purpose, we analyzed twenty popular weekly routes and the potential impact of sex and relationship status (single versus coupled) on the reported level of spatial-social activity during the quarantine in Russia between March and June 2020 (N = 492). Our study revealed a significant difference between men’s and women’s mobility: men, in general, tend to exhibit substantially higher spatial activity. The results have shown that individuals living on their own have more social interactions with friends and exhibit more profound spatial mobility via public transport. On the other hand, spatial activity of coupled individuals of both sexes were mostly devoted to solving a list of economic and matrimonial tasks. At the same time, men already cohabiting with a partner leave their homes for dating purposes more frequently than single men and women. We interpret these findings in the sense that both individual and sex-specific differences in observed sociality could be a result of a fine-tuned adaptive populational response to a contemporary virus threat, predominantly rooted in the evolution of behavioral strategies in the reproductive and economic spheres of each sex. Indeed, unlike women, coupled men have been preserving highly risky and intense social behavior during the COVID-19 pandemic.

Gendered movement ecology and landscape use in Hadza hunter-gatherers

Understanding how gendered economic roles structure space use is critical to evolutionary models of foraging behaviour, social organization and cognition. Here, we examine hunter-gatherer spatial behaviour on a very large scale, using GPS devices worn by Hadza foragers to record 2,078 person-days of movement. Theory in movement ecology suggests that the density and mobility of targeted foods should predict spatial behaviour and that strong gender differences should arise in a hunter-gatherer context. As predicted, we find that men walked further per day, explored more land, followed more sinuous paths and were more likely to be alone. These data are consistent with the ecology of male- and female-targeted foods and suggest that male landscape use is more navigationally challenging in this hunter-gatherer context. Comparisons of Hadza space use with space use data available for non-human primates suggest that the sexual division of labour likely co-evolved with increased sex differences in spatial behaviour and landscape use.

Short- and long-term memory and age in a traditional tribe (Dani of Papua) and a modern population (Poland)

The different environmental conditions in which people live might challenge memory in different ways. Moreover, the frequency of usage can be a source of improvement of both short- and long-term memory. The aim of our study was to investigate the effects of environmental differences on short- and long-term memory in a traditional versus a contemporary population (Dani of Papua, n = 62; Polish, n = 134). We found that both short- and long-term memory varied in the two populations, living in totally distinct surroundings. However, there were no age differences between Polish and Dani participants in either short- or long-term memory tasks, indicating that culture was not a significant moderator of the memory differences between populations. The differences in short- and long-term memory between the two populations are consistent with the argument that short-term memory plays a more significant role in contemporary societies because of technical developments, the electronic revolution, and reading ability. The lack of an age difference appears to support the assumption that it is age, not culture, that plays a crucial role in the memory performance.

The Effectiveness of Home-Based Training Software Designed to Influence Strategic Navigation Preferences in Healthy Subjects

One approach to the rehabilitation of navigation impairments is to train the use of compensatory egocentric or allocentric navigation strategies. Yet, it is unknown whether and to what degree training programs can influence strategic navigation preferences. In validating this approach, the key assumption that strategic preference can be changed by using a navigation training was assessed in a group of healthy participants (n = 82). The training program consisted of a psychoeducation session and a software package that included either allocentric or egocentric navigation exercises in virtual environments. Strategic navigation preference, objective and self-reported spatial abilities were assessed in pre- and post-training sessions. Based on their pre-training strategic preference, participants received either the egocentric training (n = 19) or the allocentric training (n = 21) version of the training. These participants engaged in four training sessions over a period of 2-3 weeks. The second group of participants did not use the training software (n = 43) and served as a control group. The results show that 50% of participants that received the egocentric training shifted from an allocentric to and an egocentric strategic preference. The proportion of participants that switched their strategic preference as a result of the allocentric training was identical to this proportion in the control group (19%). The training did not affect objective and self-reported navigation abilities as measured in the pre- and post-training sessions. We conclude that strategic navigation preferences can be influenced by using home-based training in healthy participants. However, using the current approach, only a preference shift from an allocentric to an egocentric navigation strategy could be achieved. The effectiveness of this navigation strategy training should next be assessed in relevant patient populations.

Sun, age and test location affect spatial orientation in human foragers in rainforests

The ability to know the direction of food sources is important for the foraging success of hunter-gatherers, especially in rainforests where dense vegetation limits visual detection distances. Besides sex and age, prior experience with the environment and the use of environmental cues are known to influence orientation abilities of humans. Among environmental cues, the position of the sun in the sky is important for orientation of diurnal animal species. However, whether or to what extent humans use the sun is largely unknown. Here, we investigated orientation abilities of the Mbendjele BaYaka people in the Republic of Congo, by conducting pointing tests (Nparticipants = 54, age: 6-76 years) in different locations in the rainforest. The Mbendjele were overall highly accurate at pointing to out-of-sight targets (median error: 6°). Pointing accuracy increased with age, but sex did not affect accuracy. Crucially, sun visibility increased pointing accuracy in young participants, especially when they were far from the camp. However, this effect became less apparent in older participants who exhibited high pointing accuracy, also when the sun was not visible. This study extends our understandings of orientation abilities of human foragers and provides the first behavioural evidence for sun compass use in humans.

Adaptive Capacity: An Evolutionary Neuroscience Model Linking Exercise, Cognition, and Brain Health

The field of cognitive neuroscience was transformed by the discovery that exercise induces neurogenesis in the adult brain, with the potential to improve brain health and stave off the effects of neurodegenerative disease. However, the basic mechanisms underlying exercise-brain connections are not well understood. We use an evolutionary neuroscience approach to develop the adaptive capacity model (ACM), detailing how and why physical activity improves brain function based on an energy-minimizing strategy. Building on studies showing a combined benefit of exercise and cognitive challenge to enhance neuroplasticity, our ACM addresses two fundamental questions: (i) what are the proximate and ultimate mechanisms underlying age-related brain atrophy, and (ii) how do lifestyle changes influence the trajectory of healthy and pathological aging?