Gender differences in BaYaka forager sleep-wake patterns in forest and village contexts

Abstract

Sleep studies in small-scale subsistence societies have broadened our understanding of cross-cultural sleep patterns, revealing the flexibility of human sleep. We examined sleep biology among BaYaka foragers from the Republic of Congo who move between environmentally similar but socio-ecologically distinct locations to access seasonal resources. We analyzed the sleep–wake patterns of 51 individuals as they resided in a village location (n = 39) and a forest camp (n = 23) (362 nights total). Overall, BaYaka exhibited high sleep fragmentation (50.5) and short total sleep time (5.94 h), suggestive of segmented sleep patterns. Sleep duration did not differ between locations, although poorer sleep quality was exhibited in the village. Linear mixed effect models demonstrated that women’s sleep differed significantly from men’s in the forest, with longer total sleep time (β ± SE = − 0.22 ± 0.09, confidence interval (CI) = [− 0.4, − 0.03]), and higher sleep quality (efficiency; β ± SE = − 0.24 ± 0.09, CI = [− 0.42, − 0.05]). These findings may be due to gender-specific social and economic activities. Circadian rhythms were consistent between locations, with women exhibiting stronger circadian stability. We highlight the importance of considering intra-cultural variation in sleep–wake patterns when taking sleep research into the field.

Sleep tight! Adolescent sleep quality across three distinct sleep ecologies

“…Our findings here add to the currently limited empirical evidence of sleep quality in rural and non-industrial adolescent populations given that research so far has focused chiefly on teen sleep duration and timing [ 18 , 33 , 41–46 ]. Consistent with previous research examining adult sleep in communities with limited or no access to electricity [ 26–33 ], this study results call into question conventional wisdom and current ideal sleep parameters based on Western cultural assumptions and practices [ 40 ], stating that people living in small-scale, non-industrial or rural contexts sleep for longer and experience less fragmented sleep than those in post-industrial societies [ 26 ].…”

“…The above findings question current ideal sleep parameters based on Western cultural assumptions and practices [ 40 ], as well as perceived wisdom asserting that compared to post-industrial societies, people in small-scale, rural or non-industrial contexts experience less fragmented (i.e. more efficient), longer bouts of sleep [ 26 ]. Nevertheless, empirical evidence of sleep quality in rural and non-industrial adolescent populations is limited given that research has focused chiefly on teen sleep duration and timing [ 18 , 33 , 41–46 ].…”

“…Previous research examining sleep in contemporary adult hunter–gatherers, forest foragers, horticulturalists and rural communities with limited or no access to electricity, have reported sleep efficiency estimates between 66.4% and 88.7% [ 26–33 ], at times below the cut-off value of 85% for normal healthy sleep established in adult industrial populations [ 34 ] (86% for the case of adolescents [ 20 ]). Similarly, these non-clinical studies have reported wide variability in sleep durations, with averages ranging between 5.7 and 8.5 h/day [ 26–33 , 35–39 ]. Additionally, it has been noted that insomnia complaints for initiating or maintaining sleep are rare in some of these groups, where local languages do not have a word for insomnia (e.g.…”

The pregnancy compensation hypothesis, not the staying alive theory, accounts for disparate autoimmune functioning of women around the world

“…Some evidence indicates that women sleep longer than men (Burgard & Ailshire, 2013) and have better sleep quality (Faria et al, 2019). In BaYaka foragers (Kilius et al, 2021), males displayed a higher variance in sleep patterns and spent more time socializing during nighttime.…”

The Relationships between Physical Activity, Screen Time and Sleep Time According to the Adolescents’ Sex and the Day of the Week

“…Adolescent sleep patterns are quite similar between males and females [ 18 ], including sleep time [ 9 ], although females sleep longer on average [ 11 , 19 ]. Sleep time decreases with age, except for a slight increase after the age of 60 [ 20 ].…”