TY - JOUR
T1 - Cognitive performance across the life course of bolivian forager-farmers with limited schooling
AU - Gurven, Michael
AU - Fuerstenberg, Eric
AU - Trumble, Benjamin
AU - Stieglitz, Jonathan
AU - Beheim, Bret
AU - Davis, Helen
AU - Kaplan, Hillard
N1 - Funding Information:
We thank the Tsimane for participating and THLHP personnel for collecting and coding data. Research was supported by grants to Michael Gurven and Hillard Kaplan from the National Institutes of Health (NIH)/National Institute on Aging (NIA) (R01AG024119, R56AG024119) and the National Science Foundation (NSF) (BCS-0422690). Jonathan Stieglitz and Michael Gurven acknowledge support from the Agence Nationale de la Recherche (ANR)? Labex IAST.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g., "effortful processing" abilities, including fluid reasoning and processing speed) improve throughout early adolescence and start declining in early adulthood, whereas other abilities (e.g., "crystallized" abilities like vocabulary breadth) improve throughout adult life, remaining robust even at late ages. Although schooling may impact performance and cognitive "reserve," it has been argued that these age patterns of cognitive performance are human universals. Here we examine age patterns of cognitive performance among Tsimane forager-horticulturalists of Bolivia and test whether schooling is related to differences in cognitive performance over the life course to assess models of active versus passive cognitive reserve. We used a battery of eight tasks to assess a range of latent cognitive traits reflecting attention, processing speed, verbal declarative memory, and semantic fluency (n = 919 individuals, 49.9% female). Tsimane cognitive abilities show similar age-related differences as observed in industrialized populations: higher throughout adolescence and only slightly lower in later adulthood for semantic fluency but substantially lower performance beginning in early adulthood for all other abilities. Schooling is associated with greater cognitive abilities at all ages controlling for sex but has no attenuating effect on cognitive performance in late adulthood, consistent with models of passive cognitive reserve. We interpret the minimal attenuation of semantic fluency late in life in light of evolutionary theories of postreproductive life span, which emphasize indirect fitness contributions of older adults through the transfer of information, labor, and food to descendant kin.
AB - Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g., "effortful processing" abilities, including fluid reasoning and processing speed) improve throughout early adolescence and start declining in early adulthood, whereas other abilities (e.g., "crystallized" abilities like vocabulary breadth) improve throughout adult life, remaining robust even at late ages. Although schooling may impact performance and cognitive "reserve," it has been argued that these age patterns of cognitive performance are human universals. Here we examine age patterns of cognitive performance among Tsimane forager-horticulturalists of Bolivia and test whether schooling is related to differences in cognitive performance over the life course to assess models of active versus passive cognitive reserve. We used a battery of eight tasks to assess a range of latent cognitive traits reflecting attention, processing speed, verbal declarative memory, and semantic fluency (n = 919 individuals, 49.9% female). Tsimane cognitive abilities show similar age-related differences as observed in industrialized populations: higher throughout adolescence and only slightly lower in later adulthood for semantic fluency but substantially lower performance beginning in early adulthood for all other abilities. Schooling is associated with greater cognitive abilities at all ages controlling for sex but has no attenuating effect on cognitive performance in late adulthood, consistent with models of passive cognitive reserve. We interpret the minimal attenuation of semantic fluency late in life in light of evolutionary theories of postreproductive life span, which emphasize indirect fitness contributions of older adults through the transfer of information, labor, and food to descendant kin.
KW - Aging
KW - Cognitive performance
KW - Cognitive reserve
KW - Education
KW - Fluid versus crystallized intelligence
KW - Tsimane
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U2 - 10.1037/dev0000175
DO - 10.1037/dev0000175
M3 - Article
C2 - 27584668
AN - SCOPUS:84984710728
VL - 53
SP - 160
EP - 176
JO - Developmental Psychology
JF - Developmental Psychology
SN - 0012-1649
IS - 1
ER -