Rolf Degen summarizes: Contrary to earlier believes, humans have at least as many - if not more - Olfactory Receptor genes as monkeys and apes, with color vision being no limiting factor

Evolution of Genes for Color Vision and the Chemical Senses in Primates. Shoji Kawamura, Amanda D. Melin. Chapter in Evolution of the Human Genome I. https://link.springer.com/chapter/10.1007/978-4-431-56603-8_10

Abstract: Primates are generally regarded as visually oriented mammals, trading a sense of smell for good sight. However, recent studies have questioned this simplistic view, and it is not well understood the extent to which senses have evolved interactively or in concert with each other in primates including humans. For example, the number of olfactory receptor genes is not as clearly differentiated between species with different color vision as once asserted. Among senses, receptors of stimuli for vision, olfaction, and bitter/sweet/umami tastes all belong to the G-protein-coupled receptor (GPCR) family, for which the genetic mechanism of signal perception is well understood. Thus, it is now possible to explore the evolutionary correlation among different senses in primates by studying these receptor groups for interspecies divergence, intraspecies diversity, and functional differences among variants. In this chapter, we review recent findings on these receptors and senses in humans and other primates and discuss the future directions of studies on their sensory evolution.



[Screenshot from https://twitter.com/DegenRolf/status/961876566023143424]

People struggle to name odors, but this limitation is not universal. Is superior olfactory performance due to subsistence, ecology or language family? Subsistence.

Hunter-Gatherer Olfaction Is Special. Asifa Majid, Nicole Kruspe. Current Biology, https://doi.org/10.1016/j.cub.2017.12.014 |

Highlights
    •    People struggle to name odors, but this limitation is not universal
    •    Is superior olfactory performance due to subsistence, ecology or language family?
    •    Hunter-gatherers and non-hunter-gatherers from the same environment were compared
    •    Only hunter-gatherers were proficient odor namers, showing subsistence is crucial

Summary: People struggle to name odors [1, 2, 3, 4]. This has been attributed to a diminution of olfaction in trade-off to vision [5, 6, 7, 8, 9, 10]. This presumption has been challenged recently by data from the hunter-gatherer Jahai who, unlike English speakers, find odors as easy to name as colors [4]. Is the superior olfactory performance among the Jahai because of their ecology (tropical rainforest), their language family (Aslian), or because of their subsistence (they are hunter-gatherers)? We provide novel evidence from the hunter-gatherer Semaq Beri and the non-hunter-gatherer (swidden-horticulturalist) Semelai that subsistence is the critical factor. Semaq Beri and Semelai speakers—who speak closely related languages and live in the tropical rainforest of the Malay Peninsula—took part in a controlled odor- and color-naming experiment. The swidden-horticulturalist Semelai found odors much more difficult to name than colors, replicating the typical Western finding. But for the hunter-gatherer Semaq Beri odor naming was as easy as color naming, suggesting that hunter-gatherer olfactory cognition is special.

Why do boys and girls make different educational choices? The influence of expected earnings and test scores

Why do boys and girls make different educational choices? The influence of expected earnings and test scores. Benoît Rapoport, Claire Thibout. Economics of Education Review, Volume 62, February 2018, Pages 205-229. https://doi.org/10.1016/j.econedurev.2017.09.006

Highlights
•    Expected earnings drive the educational choices of boys more so than for girls.
•    Girls generally place less value on their test scores in Sciences than boys.
•    The gender gap in high school course choices is higher for pupils at the same level in Mathematics and Humanities.
•    The gender gap in high school is mainly due to differences in valuation of test scores.
•    The gender gap in higher education choices largely come from differences in tastes or norms.

Abstract: Girls frequently choose educational pathways that lead to lower-paid jobs and less prestigious careers, despite performing as well as boys at school. Using a cohort of French pupils, we estimate a model of educational choices in which the anticipated cost of choosing a pathway depends on the skills in each subject and is allowed to differ between boys and girls. We show that choices in high school and in higher education are partly driven by expected earnings for boys but less for girls. Boys choose more often courses with a component in Sciences and competitive pathways. In high school, gender differences are higher for pupils at the same level in Mathematics and Humanities and are largely due to differences in marginal impact of test scores, which are lower for girls. In higher education, while partly driven by test scores, choices seem to largely depend on other gender differences (tastes, norms).

Self-Control in Chimpanzees Relates to General Intelligence (As It Seems to Happen in Humans)

Self-Control in Chimpanzees Relates to General Intelligence. Michael J. Beran, William D. Hopkins. Current Biology, https://doi.org/10.1016/j.cub.2017.12.043

Highlights
    •    In humans, delay of gratification appears to be related to general intelligence
    •    Chimpanzees completed an intelligence test and a test of delay of gratification
    •    Intelligence scores were most closely related to delay-of-gratification efficiency
    •    Factors that loaded most strongly on g scores were most related to delay scores

Summary: For humans, there appears to be a clear link between general intelligence and self-control behavior, such as sustained delay of gratification [1, 2, 3, 4, 5, 6, 7, 8, 9]. Chimpanzees also delay gratification [10, 11, 12] and can be given tests of general intelligence (g) [13, 14, 15], but these two constructs have never been compared within the same sample of nonhuman animals. We presented 40 chimpanzees with the hybrid delay task (HDT) [16, 17], which measures inter-temporal choices and the capacity for sustained delay of gratification, and the primate cognitive test battery (PCTB), which measures g in chimpanzees [13, 14, 15]. Importantly, none of the sub-tasks in the PCTB directly assesses self-control or other forms of behavioral inhibition. Rather, they assess areas of physical cognition (e.g., quantity discrimination) or social cognition (e.g., gaze following). In three phases of testing, we consistently found that the strongest relation was between chimpanzee g scores and efficiency in the HDT. Chimpanzee g was not most closely related to the proportion of trials the chimpanzees chose to try to wait for delayed rewards, but rather most closely related to how good they were at waiting for those rewards when they chose to do so. We also found the same strong relation between HDT efficiency and those factors in the PCTB that loaded most strongly on chimpanzee g. These results highlight that, as with humans, there is a strong relation between chimpanzees’ self-control and overall intelligence—a relation that likely reflects the role of successful inhibitory control during cognitive processing of information and intelligent decision-making.