My subject is composed of two disparate pieces with an equation in common. The pieces are separated by geography and culture; time and economic mode of production; and by academic discipline and literature. These differences are manifest and important; the feature that they have in common is somewhat more subtle.

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.

There are mixed findings with respect to individual or gender differences in virtual Morris water maze tasks, which may be attributed to variations in the scale of the space, the cues provided, and differences in spatial navigation experience and abilities. We explore the question of scale and context by presenting participants with either a large (146 m) or small (36 m) outdoor virtual Morris maze, along with a measure of lifetime mobility and mental rotation skills. Results of this study suggest that, for the small-scale environment, males and females performed similarly when asked to navigate with only close visual cues. However, males outperformed females when only far cues were visible. In the large-scale environment, males outperformed females in both cue conditions. Additionally, mental rotation abilities predicted better navigation performance with close cues only. Finally, we found that highly mobile females and males perform equally well when navigating with close cues.

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.