Relative Effects of Forward and Backward Planning on Goal Pursuit. Jooyoung Park, Fang-Chi Lu, and William M. Hedgcock. Psychological Science, https://doi.org/10.1177/0956797617715510
Abstract: Considerable research has shown that planning plays an important role in goal pursuit. But how does the way people plan affect goal pursuit? Research on this question is scarce. In the current research, we examined how planning the steps required for goal attainment in chronological order (i.e., forward planning) and reverse chronological order (i.e., backward planning) influences individuals’ motivation for and perceptions of goal pursuit. Compared with forward planning, backward planning not only led to greater motivation, higher goal expectancy, and less time pressure but also resulted in better goal-relevant performance. We further demonstrated that this motivational effect occurred because backward planning allowed people to think of tasks required to reach their goals more clearly, especially when goals were complex to plan. These findings suggest that the way people plan matters just as much as whether or not they plan.
Bipartisan Alliance, a Society for the Study of the US Constitution, and of Human Nature, where Republicans and Democrats meet.
Thursday, September 14, 2017
Wind farms suppressed soil moisture and enhanced water stress
The Observed Impacts of Wind Farms on Local Vegetation Growth in Northern China. Bijian Tang et al.
Abstract: Wind farms (WFs) can affect the local climate, and local climate change may influence underlying vegetation. Some studies have shown that WFs affect certain aspects of the regional climate, such as temperature and rainfall. However, there is still no evidence to demonstrate whether WFs can affect local vegetation growth, a significant part of the overall assessment of WF effects. In this research, based on the moderate-resolution imaging spectroradiometer (MODIS) vegetation index, productivity and other remote-sensing data from 2003 to 2014, the effects of WFs in the Bashang area of Northern China on vegetation growth and productivity in the summer (June–August) were analyzed. The results showed that: (1) WFs had a significant inhibiting effect on vegetation growth, as demonstrated by decreases in the leaf area index (LAI), the enhanced vegetation index (EVI), and the normalized difference vegetation index (NDVI) of approximately 14.5%, 14.8%, and 8.9%, respectively, in the 2003–2014 summers. There was also an inhibiting effect of 8.9% on summer gross primary production (GPP) and 4.0% on annual net primary production (NPP) coupled with WFs; and (2) the major impact factors might be the changes in temperature and soil moisture: WFs suppressed soil moisture and enhanced water stress in the study area. This research provides significant observational evidence that WFs can inhibit the growth and productivity of the underlying vegetation.
Keywords: wind farm impact; vegetation decrease; satellite observations; GPP; land surface temperature; land use change
My comment: Despite knowing this and many other reasons, we keep supporting wind farms...
Abstract: Wind farms (WFs) can affect the local climate, and local climate change may influence underlying vegetation. Some studies have shown that WFs affect certain aspects of the regional climate, such as temperature and rainfall. However, there is still no evidence to demonstrate whether WFs can affect local vegetation growth, a significant part of the overall assessment of WF effects. In this research, based on the moderate-resolution imaging spectroradiometer (MODIS) vegetation index, productivity and other remote-sensing data from 2003 to 2014, the effects of WFs in the Bashang area of Northern China on vegetation growth and productivity in the summer (June–August) were analyzed. The results showed that: (1) WFs had a significant inhibiting effect on vegetation growth, as demonstrated by decreases in the leaf area index (LAI), the enhanced vegetation index (EVI), and the normalized difference vegetation index (NDVI) of approximately 14.5%, 14.8%, and 8.9%, respectively, in the 2003–2014 summers. There was also an inhibiting effect of 8.9% on summer gross primary production (GPP) and 4.0% on annual net primary production (NPP) coupled with WFs; and (2) the major impact factors might be the changes in temperature and soil moisture: WFs suppressed soil moisture and enhanced water stress in the study area. This research provides significant observational evidence that WFs can inhibit the growth and productivity of the underlying vegetation.
Keywords: wind farm impact; vegetation decrease; satellite observations; GPP; land surface temperature; land use change
My comment: Despite knowing this and many other reasons, we keep supporting wind farms...
Wheat Agriculture Induce Bigger GDP, Which Yields Smaller Family Ties
Wheat Agriculture and Family Ties. James Ang & Per Fredriksson. European Economic Review, Volume 100, November 2017, Pages 236-256, https://doi.org/10.1016/j.euroecorev.2017.08.007
Abstract: Several recent contributions to the literature have suggested that the strength of family ties is related to various economic and social outcomes. For example, Alesina and Giuliano (2014) highlight that the strength of family ties is strongly correlated with lower GDP and lower quality of institutions. However, the forces shaping family ties remain relatively unexplored in the literature. This paper proposes and tests the hypothesis that the agricultural legacy of a country matters for shaping the strength of its family ties. Using data from the World Values Survey and the European Values Study, the results show that societies with a legacy in cultivating wheat tend to have weaker family ties. Analysis at the sub-national level (US data) and the country level corroborate these findings. The estimations allow for alternative hypotheses which propose that pathogen stress and climatic variation can potentially also give rise to the formation of family ties. The results suggest that the suitability of land for wheat production is the most influential factor in explaining the variation in the strength of family ties across societies and countries.
Abstract: Several recent contributions to the literature have suggested that the strength of family ties is related to various economic and social outcomes. For example, Alesina and Giuliano (2014) highlight that the strength of family ties is strongly correlated with lower GDP and lower quality of institutions. However, the forces shaping family ties remain relatively unexplored in the literature. This paper proposes and tests the hypothesis that the agricultural legacy of a country matters for shaping the strength of its family ties. Using data from the World Values Survey and the European Values Study, the results show that societies with a legacy in cultivating wheat tend to have weaker family ties. Analysis at the sub-national level (US data) and the country level corroborate these findings. The estimations allow for alternative hypotheses which propose that pathogen stress and climatic variation can potentially also give rise to the formation of family ties. The results suggest that the suitability of land for wheat production is the most influential factor in explaining the variation in the strength of family ties across societies and countries.
Extraversion and life satisfaction: A cross-cultural examination of student and nationally representative samples
Kim, H., Schimmack, U., Oishi, S. and Tsutsui, Y. (), Extraversion and life satisfaction: A cross-cultural examination of student and nationally representative samples. Journal of Personality. Accepted Author Manuscript. doi:10.1111/jopy.12339
Method: The current study examined student and nationally representative samples from Canada, US, UK, Germany and Japan (Study 1, N = 1,460; Study 2, N = 5,882; Study 3, N =18,683; Study 4, N = 13,443; Study 5, Japan N = 952 and US N = 891). The relationship between Extraversion and life satisfaction was examined using structural equation modeling by regressing life satisfaction on the Big Five traits.
Results: Extraversion was a unique predictor of life satisfaction in the North American student and nationally representative samples (Study 1, β = .232; Study 2, β = .225; Study 5, β = .217) but the effect size was weaker or absent in other non-North American samples (Germany, UK, and Japan).
Method: The current study examined student and nationally representative samples from Canada, US, UK, Germany and Japan (Study 1, N = 1,460; Study 2, N = 5,882; Study 3, N =18,683; Study 4, N = 13,443; Study 5, Japan N = 952 and US N = 891). The relationship between Extraversion and life satisfaction was examined using structural equation modeling by regressing life satisfaction on the Big Five traits.
Results: Extraversion was a unique predictor of life satisfaction in the North American student and nationally representative samples (Study 1, β = .232; Study 2, β = .225; Study 5, β = .217) but the effect size was weaker or absent in other non-North American samples (Germany, UK, and Japan).
Can Superstition Create a Self-Fulfilling Prophecy? School Outcomes of Dragon Children of China
Can Superstition Create a Self-Fulfilling Prophecy? School Outcomes of Dragon Children of China. Naci Mocan and Han Yu. NBER Working Paper, August 2017, http://www.nber.org/papers/w23709
Abstract: In Chinese culture those who are born in the year of the Dragon under the zodiac calendar are believed to be destined for good fortune and greatness, and parents prefer their kids to be born in a Dragon year. Using province level panel data we show that the number of marriages goes up during the two years preceding a Dragon year and that births jump up in a Dragon year. Using three recently collected micro data sets from China we show that those born in a Dragon year are more likely to have a college education, and that they obtain higher scores at the university entrance exam. Similarly, Chinese middle school students have higher test scores if they are born in a Dragon year. We show that these results are not because of family background, student cognitive ability, self-esteem or students’ expectations about their future. We find, however, that the “Dragon” effect on test scores is eliminated when we account for parents’ expectations about their children’s educational and professional success. We find that parents of Dragon children have higher expectations for their children in comparison to other parents, and that they invest more heavily in their children in terms of time and money. Even though neither the Dragon children nor their families are inherently different from other children and families, the belief in the prophecy of success and the ensuing investment become self-fulfilling.
Abstract: In Chinese culture those who are born in the year of the Dragon under the zodiac calendar are believed to be destined for good fortune and greatness, and parents prefer their kids to be born in a Dragon year. Using province level panel data we show that the number of marriages goes up during the two years preceding a Dragon year and that births jump up in a Dragon year. Using three recently collected micro data sets from China we show that those born in a Dragon year are more likely to have a college education, and that they obtain higher scores at the university entrance exam. Similarly, Chinese middle school students have higher test scores if they are born in a Dragon year. We show that these results are not because of family background, student cognitive ability, self-esteem or students’ expectations about their future. We find, however, that the “Dragon” effect on test scores is eliminated when we account for parents’ expectations about their children’s educational and professional success. We find that parents of Dragon children have higher expectations for their children in comparison to other parents, and that they invest more heavily in their children in terms of time and money. Even though neither the Dragon children nor their families are inherently different from other children and families, the belief in the prophecy of success and the ensuing investment become self-fulfilling.
Speaking about the future in the present tense may result in the belief that adverse credit events are more imminent
Languages and Corporate Savings Behavior. Shimin Chen et al. Journal of Corporate Finance, Vol. 46, October 2017, Pages 320-341, https://doi.org/10.1016/j.jcorpfin.2017.07.009
Abstract: Speakers of strong future time reference (FTR) languages (e.g., English) are required to grammatically distinguish between future and present events, while speakers of weak-FTR languages (e.g., Chinese) are not. We hypothesize that speaking about the future in the present tense may result in the belief that adverse credit events are more imminent. Consistent with such a linguistic hypothesis, weak-FTR language firms are found to have higher precautionary cash holdings. We report additional supportive results from changes in the relative importance of different languages in a country’s business domain, evidence from within one country with several distinct languages, and results related to changes following a severe financial crisis. Our evidence introduces a new explanation for heterogeneity in corporate savings behavior, provides insights about belief formation in firms, and adds to research on the effects of languages on economic outcomes.
Abstract: Speakers of strong future time reference (FTR) languages (e.g., English) are required to grammatically distinguish between future and present events, while speakers of weak-FTR languages (e.g., Chinese) are not. We hypothesize that speaking about the future in the present tense may result in the belief that adverse credit events are more imminent. Consistent with such a linguistic hypothesis, weak-FTR language firms are found to have higher precautionary cash holdings. We report additional supportive results from changes in the relative importance of different languages in a country’s business domain, evidence from within one country with several distinct languages, and results related to changes following a severe financial crisis. Our evidence introduces a new explanation for heterogeneity in corporate savings behavior, provides insights about belief formation in firms, and adds to research on the effects of languages on economic outcomes.
Marriage Gap in Christians and Muslims
Marriage Gap in Christians and Muslims. Martin Fieder et al. Journal of Biosocial Science, https://doi.org/10.1017/S0021932017000086
Summary: For modern Western societies with a regime of monogamy, it has recently been demonstrated that the socioeconomic status of men is positively associated with being or having been married. This study aims to compare marriage patterns (if a person has been married at least once) for cultures with a tradition of monogamy and polygyny. As no worldwide data on polygyny exist, religion was used as a proxy for monogamy (Christians) vs polygyny (Muslims). The analyses were based on 2000–2011 census data from 39 countries worldwide for 52,339,594 men and women, controlling for sex, sex ratio, age, education, migration within the last 5 years and employment. Overall, a higher proportion of Muslims were married compared with Christians, but the difference in the fraction of married men compared with married women at a certain age (the ‘marriage gap’) was much more pronounced in Muslims than in Christians, i.e. compared with Christians, a substantially higher proportion of Muslim women than men were married up to the age of approximately 31 years. As expected for a tradition of polygyny, the results indicate that the socioeconomic threshold for entering marriage is higher for Muslim than Christian men, and Muslim women in particular face a negative effect of socioeconomic status on the probability of ever being married. The large ‘marriage gap’ at a certain age in Muslim societies leads to high numbers of married women and unmarried young men, and may put such polygenic societies under pressure.
Summary: For modern Western societies with a regime of monogamy, it has recently been demonstrated that the socioeconomic status of men is positively associated with being or having been married. This study aims to compare marriage patterns (if a person has been married at least once) for cultures with a tradition of monogamy and polygyny. As no worldwide data on polygyny exist, religion was used as a proxy for monogamy (Christians) vs polygyny (Muslims). The analyses were based on 2000–2011 census data from 39 countries worldwide for 52,339,594 men and women, controlling for sex, sex ratio, age, education, migration within the last 5 years and employment. Overall, a higher proportion of Muslims were married compared with Christians, but the difference in the fraction of married men compared with married women at a certain age (the ‘marriage gap’) was much more pronounced in Muslims than in Christians, i.e. compared with Christians, a substantially higher proportion of Muslim women than men were married up to the age of approximately 31 years. As expected for a tradition of polygyny, the results indicate that the socioeconomic threshold for entering marriage is higher for Muslim than Christian men, and Muslim women in particular face a negative effect of socioeconomic status on the probability of ever being married. The large ‘marriage gap’ at a certain age in Muslim societies leads to high numbers of married women and unmarried young men, and may put such polygenic societies under pressure.
Highly educated women tend to partner more often “downwards” with less educated men, rather than remaining single
The Reversed Gender Gap in Education and Assortative Mating in Europe. De Hauw, Yolien, Grow, Andre, and Van Bavel, Jan. European Journal of Population, https://link.springer.com/article/10.1007/s10680-016-9407-z
Abstract: While in the past men received more education than women, the gender gap in education has turned around: in recent years, more highly educated women than highly educated men are reaching the reproductive ages. Using data from the European Social Survey (rounds 1–6), we investigate the implications of this reversed gender gap for educational assortative mating. We fit multilevel multinomial regression models to predict the proportions of men and women living with a partner of a given level of education, contingent on respondents’ own educational attainment and on the cohort-specific sex ratio among the population with tertiary education at the country level. We find that highly educated women tend to partner more often “downwards” with less educated men, rather than remaining single more often. Medium educated women are found to partner less often “upwards” with highly educated men. For men, there is no evidence that they are more likely to partner with highly educated women. Rather, they are found to be living single more often. In sum, women’s advantage in higher education has affected mating patterns in important ways: while women previously tended to form unions with men who were at least as highly educated as themselves, they now tend to live with men who are at most as highly educated. Along the way, advanced education became a bonus on the mating market for women as well as for men.
Abstract: While in the past men received more education than women, the gender gap in education has turned around: in recent years, more highly educated women than highly educated men are reaching the reproductive ages. Using data from the European Social Survey (rounds 1–6), we investigate the implications of this reversed gender gap for educational assortative mating. We fit multilevel multinomial regression models to predict the proportions of men and women living with a partner of a given level of education, contingent on respondents’ own educational attainment and on the cohort-specific sex ratio among the population with tertiary education at the country level. We find that highly educated women tend to partner more often “downwards” with less educated men, rather than remaining single more often. Medium educated women are found to partner less often “upwards” with highly educated men. For men, there is no evidence that they are more likely to partner with highly educated women. Rather, they are found to be living single more often. In sum, women’s advantage in higher education has affected mating patterns in important ways: while women previously tended to form unions with men who were at least as highly educated as themselves, they now tend to live with men who are at most as highly educated. Along the way, advanced education became a bonus on the mating market for women as well as for men.
In men, education is positively associated with eventual fertility
Education, Other Socioeconomic Characteristics Across the Life Course, and Fertility Among Finnish Men. Jessica Nisén et al. European Journal of Population, https://link.springer.com/article/10.1007/s10680-017-9430-8
Abstract: The level of education and other adult socioeconomic characteristics of men are known to associate with their fertility, but early-life socioeconomic characteristics may also be related. We studied how men’s adult and early-life socioeconomic characteristics are associated with their eventual fertility and whether the differences therein by educational level are explained or mediated by other socioeconomic characteristics. The data on men born in 1940–1950 (N = 37,082) were derived from the 1950 Finnish census, which is linked to later registers. Standard and sibling fixed-effects Poisson and logistic regression models were used. Education and other characteristics were positively associated with the number of children, largely stemming from a higher likelihood of a first birth among the more socioeconomically advantaged men. The educational gradient in the number of children was not explained by early socioeconomic or other characteristics shared by brothers, but occupational position and income in adulthood mediated approximately half of the association. Parity-specific differences existed: education and many other socioeconomic characteristics predicted the likelihood of a first birth more strongly than that of a second birth, and the mediating role of occupational position and income was also strongest for first births. Relatively small differences were found in the likelihood of a third birth. In men, education is positively associated with eventual fertility after controlling for early socioeconomic and other characteristics shared by brothers. Selective entry into fatherhood based on economic provider potential may contribute considerably to educational differentials in the number of children among men.
Abstract: The level of education and other adult socioeconomic characteristics of men are known to associate with their fertility, but early-life socioeconomic characteristics may also be related. We studied how men’s adult and early-life socioeconomic characteristics are associated with their eventual fertility and whether the differences therein by educational level are explained or mediated by other socioeconomic characteristics. The data on men born in 1940–1950 (N = 37,082) were derived from the 1950 Finnish census, which is linked to later registers. Standard and sibling fixed-effects Poisson and logistic regression models were used. Education and other characteristics were positively associated with the number of children, largely stemming from a higher likelihood of a first birth among the more socioeconomically advantaged men. The educational gradient in the number of children was not explained by early socioeconomic or other characteristics shared by brothers, but occupational position and income in adulthood mediated approximately half of the association. Parity-specific differences existed: education and many other socioeconomic characteristics predicted the likelihood of a first birth more strongly than that of a second birth, and the mediating role of occupational position and income was also strongest for first births. Relatively small differences were found in the likelihood of a third birth. In men, education is positively associated with eventual fertility after controlling for early socioeconomic and other characteristics shared by brothers. Selective entry into fatherhood based on economic provider potential may contribute considerably to educational differentials in the number of children among men.
Enhancing a men's perception of their own mate value shifts attitude toward casual sex to very interested
Marzoli, D., Havlícek, J. and Roberts, S. C. (2017), Human mating strategies: from past causes to present consequences. WIREs Cognitive Science, e1456. doi:10.1002/wcs.1456
Abstract: In both humans and nonhuman animals, mating strategies represent a set of evolutionary adaptations aimed at promoting individual fitness by means of reproduction with the best possible partners. Given this critical role, mating strategies influence numerous aspects of human life. In particular, between-sex divergence in the intensity of intrasexual competition could account for robust cross-cultural sex differences in psychology and behavior (e.g., personality, psychiatric disorders, social behavior, violence). Several other factors (including individual differences, relationship type and environment) affect—in an evolutionarily consistent manner—variation in mating strategy that individuals pursue (as one example, awareness of one's own attractiveness impinges on mating standards). Here we provide an overview of relevant theoretical frameworks and empirical evidence on variation in mating strategies. Given its multifaceted nature and intense research interest over several decades, this is a challenging task, and we highlight areas where further investigation is warranted in order to achieve a clearer picture and resolve apparent inconsistencies. However, we suggest that addressing outstanding questions using a variety of different methodological approaches, a deeper understanding of the cognitive representations involved in mating strategies is within reach.
Abstract: In both humans and nonhuman animals, mating strategies represent a set of evolutionary adaptations aimed at promoting individual fitness by means of reproduction with the best possible partners. Given this critical role, mating strategies influence numerous aspects of human life. In particular, between-sex divergence in the intensity of intrasexual competition could account for robust cross-cultural sex differences in psychology and behavior (e.g., personality, psychiatric disorders, social behavior, violence). Several other factors (including individual differences, relationship type and environment) affect—in an evolutionarily consistent manner—variation in mating strategy that individuals pursue (as one example, awareness of one's own attractiveness impinges on mating standards). Here we provide an overview of relevant theoretical frameworks and empirical evidence on variation in mating strategies. Given its multifaceted nature and intense research interest over several decades, this is a challenging task, and we highlight areas where further investigation is warranted in order to achieve a clearer picture and resolve apparent inconsistencies. However, we suggest that addressing outstanding questions using a variety of different methodological approaches, a deeper understanding of the cognitive representations involved in mating strategies is within reach.
The long-term decline in Greenland Ice Sheet reflectivity between 2000 and 2012 might be more significant than previously thought
How robust are in situ observations for validating satellite-derived albedo over the dark zone of the Greenland Ice Sheet? J. C. Ryan et al. Ryan, J. C., A. Hubbard, T. D. Irvine-Fynn, S. H. Doyle, J. M. Cook, M. Stibal, and J. E. Box (2017), How robust are in situ observations for validating satellite-derived albedo over the dark zone of the Greenland Ice Sheet?, Geophys. Res. Lett., 44, 6218–6225, doi:10.1002/2017GL073661.
Abstract: Calibration and validation of satellite-derived ice sheet albedo data require high-quality, in situ measurements commonly acquired by up and down facing pyranometers mounted on automated weather stations (AWS). However, direct comparison between ground and satellite-derived albedo can only be justified when the measured surface is homogeneous at the length-scale of both satellite pixel and in situ footprint. Here we use digital imagery acquired by an unmanned aerial vehicle to evaluate point-to-pixel albedo comparisons across the western, ablating margin of the Greenland Ice Sheet. Our results reveal that in situ measurements overestimate albedo by up to 0.10 at the end of the melt season because the ground footprints of AWS-mounted pyranometers are insufficient to capture the spatial heterogeneity of the ice surface as it progressively ablates and darkens. Statistical analysis of 21 AWS across the entire Greenland Ice Sheet reveals that almost half suffer from this bias, including some AWS located within the wet snow zone.
Plain Language Summary
Ground measurements of reflectivity, such as those made by automated weather stations, are often used to determine the accuracy of satellite measurements. But the footprints of the instruments mounted on automated weather stations are usually much smaller than the pixel of the satellite image, meaning that comparison between the two is only justified when the surface is relatively uniform. We use high resolution imagery collected by a UAV to demonstrate that the surface of the Greenland Ice Sheet is often not uniform at the scale of both the weather station and satellite pixel due to the presence of impurities, surface water and crevasses. This means that a point measurement of reflectivity might not capture the full variability of the surface, resulting in discrepancies when compared to satellite image pixels. Furthermore, weather stations are usually located on safe areas of flat, bare ice or snow, so they usually overestimate reflectivity in comparison to the satellite pixel. We argue that if unrepresentative ground measurements are removed from satellite comparison exercises then the uncertainty in satellite products could be reduced. Hence, the long-term decline in Greenland Ice Sheet reflectivity between 2000 and 2012 might be more significant than previously thought.
Abstract: Calibration and validation of satellite-derived ice sheet albedo data require high-quality, in situ measurements commonly acquired by up and down facing pyranometers mounted on automated weather stations (AWS). However, direct comparison between ground and satellite-derived albedo can only be justified when the measured surface is homogeneous at the length-scale of both satellite pixel and in situ footprint. Here we use digital imagery acquired by an unmanned aerial vehicle to evaluate point-to-pixel albedo comparisons across the western, ablating margin of the Greenland Ice Sheet. Our results reveal that in situ measurements overestimate albedo by up to 0.10 at the end of the melt season because the ground footprints of AWS-mounted pyranometers are insufficient to capture the spatial heterogeneity of the ice surface as it progressively ablates and darkens. Statistical analysis of 21 AWS across the entire Greenland Ice Sheet reveals that almost half suffer from this bias, including some AWS located within the wet snow zone.
Plain Language Summary
Ground measurements of reflectivity, such as those made by automated weather stations, are often used to determine the accuracy of satellite measurements. But the footprints of the instruments mounted on automated weather stations are usually much smaller than the pixel of the satellite image, meaning that comparison between the two is only justified when the surface is relatively uniform. We use high resolution imagery collected by a UAV to demonstrate that the surface of the Greenland Ice Sheet is often not uniform at the scale of both the weather station and satellite pixel due to the presence of impurities, surface water and crevasses. This means that a point measurement of reflectivity might not capture the full variability of the surface, resulting in discrepancies when compared to satellite image pixels. Furthermore, weather stations are usually located on safe areas of flat, bare ice or snow, so they usually overestimate reflectivity in comparison to the satellite pixel. We argue that if unrepresentative ground measurements are removed from satellite comparison exercises then the uncertainty in satellite products could be reduced. Hence, the long-term decline in Greenland Ice Sheet reflectivity between 2000 and 2012 might be more significant than previously thought.
Ability to rapidly and accurately compare quantities genetically linked to mathematical & general cognitive skills
Approximate number sense shares etiological overlap with mathematics and general cognitive ability. Sarah L. Lukowski et al. Intelligence, https://doi.org/10.1016/j.intell.2017.08.005
Highlights
• Approximate number sense (ANS) has genetic overlap with mathematics
• Findings show generalist genetic overlap among ANS, math, and general cognitive ability
• The pattern of results suggest etiology of ANS acuity functions similar to math, g
Abstract: Approximate number sense (ANS), the ability to rapidly and accurately compare quantities presented non-symbolically, has been proposed as a precursor to mathematics skills. Earlier work reported low heritability of approximate number sense, which was interpreted as evidence that approximate number sense acts as a fitness trait. However, viewing ANS as a fitness trait is discordant with findings suggesting that individual differences in approximate number sense acuity correlate with mathematical performance, a trait with moderate genetic effects. Importantly, the shared etiology of approximate number sense, mathematics, and general cognitive ability has remained unexamined. Thus, the etiology of approximate number sense and its overlap with math and general cognitive ability was assessed in the current study with two independent twin samples (N = 451 pairs). Results suggested that ANS acuity had moderate but significant additive genetic influences. ANS also had overlap with generalist genetic mechanisms accounting for variance and covariance in mathematics and general cognitive ability. Furthermore, ANS may have genetic factors unique to covariance with mathematics beyond overlap with general cognitive ability. Evidence across both samples was consistent with the proposal that the etiology of approximate number sense functions similar to that of mathematics and general cognitive skills.
Highlights
• Approximate number sense (ANS) has genetic overlap with mathematics
• Findings show generalist genetic overlap among ANS, math, and general cognitive ability
• The pattern of results suggest etiology of ANS acuity functions similar to math, g
Abstract: Approximate number sense (ANS), the ability to rapidly and accurately compare quantities presented non-symbolically, has been proposed as a precursor to mathematics skills. Earlier work reported low heritability of approximate number sense, which was interpreted as evidence that approximate number sense acts as a fitness trait. However, viewing ANS as a fitness trait is discordant with findings suggesting that individual differences in approximate number sense acuity correlate with mathematical performance, a trait with moderate genetic effects. Importantly, the shared etiology of approximate number sense, mathematics, and general cognitive ability has remained unexamined. Thus, the etiology of approximate number sense and its overlap with math and general cognitive ability was assessed in the current study with two independent twin samples (N = 451 pairs). Results suggested that ANS acuity had moderate but significant additive genetic influences. ANS also had overlap with generalist genetic mechanisms accounting for variance and covariance in mathematics and general cognitive ability. Furthermore, ANS may have genetic factors unique to covariance with mathematics beyond overlap with general cognitive ability. Evidence across both samples was consistent with the proposal that the etiology of approximate number sense functions similar to that of mathematics and general cognitive skills.