Some notes and speculations about various topics. ||| Gegenwärtig - vorübergehend -
wohl eher eine Gedanken- und Entwurfsammlung als ein Naturwissenschaftsblog. Die effektive Aufspaltung dieses Blogs in einen Naturwissenschaftsblog und einen rein spekulativen Blog wird voraussichtlich im Laufe dieses Jahres (2019) statt finden.
The Key to Music's Genetics - Why Music is Part of Being Human
Christian Lehmann (Sept 2014 | English Version) >Amazon<
"Christian Lehmann brings his experience as a musicologist, singer and academic to this fascinating journey through the origins of music and its role in human development, culture and society. Few books on music are as rewarding as this one. Technical terms are clearly described in a way that appeals to both the musically well-informed and the musically inexperienced. Well-chosen examples and amusing asides help to make this a highly informative and extremely readable book – a must for anyone interested in the development of music and how integral it is to the human condition."
For 32 months I studied a community in which much of life revolves around a pair of emotions. Two projects resulted. One, presented elsewhere, is an examination of how and why the given culture shapes and exploits these emotions. The second, presented below, is a consideration of the underlying capacities which make such cultural manipulation possible. Like the other authors in this volume, I hold that the experience of emotion is the combined product of cultural and biological factors. However, rather than explore that synergy, in this essay I attempt to employ the former as a lens with which to view the latter. I begin with a description of a Malay emotion which appears synonymous with shame. However, closer inspection reveals that this emotion can be elicited by two fundamentally different sets of conditions. Moreover, it seems that this duality is a pervasive feature of shame-like emotions around the world. If one adopts the position that the capacity to experience a given type of emotion is the product of evolution, then the duality of shame-like emotions is puzzling, for an evolutionary perspective suggests that each emotion ought to address a discrete facet of life. In order to unravel this puzzle, I search for clues regarding the evolutionary history of shame-like emotions and their opposites, pride-like emotions. I explore the display behaviors and cognitive demands associated with each type of emotion, and conclude that two primitive emotions, which I call Protoshame and Protopride, initially developed in order to motivate the quest for social dominance. I speculate that these emotions served as the foundation for more complex emotions which arose when hominids developed the capacity for a model of mind, that is, the ability to understand that other individuals possess minds like one’s own. Such a capacity creates the possibility of a new class of emotions, the second order emotions, which are a reaction to the subjective experiences of other individuals. After examining such first order emotions as pity and envy, I suggest that Protoshame and Protopride were transformed into two second order emotions, Early Shame and Early Pride, which extended dominance-striving motivations into the new social world created by the advent of the model of mind. However, in addition to enhancing competition, the model of the mind also facilitates cooperation. The possibility of significant cooperation resulted in the development of newersions of Shame and Pride which served to motivate conformity rather than rivalry and, in so doing, set the stage for the blossoming of culture as humankind’s primary adaptation.
Error management theory (EMT) proposes that when the costs of different types of errors are asymmetrical in their fitness consequences, natural selection will create biased cognitive mechanisms that maximize the least costly error (Haselton & Buss, 2000; Haselton & Nettle, 2006). Since the time of its initial publication, EMT has produced dozens of new hypotheses and empirical results characterizing human cognition. With a focus on the last decade of research developments, we summarize evidence of error management biases across a variety of social psychological domains, ranging from perceptions of romantic attraction to social prejudices, cooperative behaviors, and the judgment of personality traits. We then cover emerging theoretical developments, such as the role of context in affecting the magnitude of biases predicted by EMT. We conclude by addressing a recent challenge to the theory – the notion that selection should preserve true beliefs, and therefore is expected only to bias behavior, and not underlying beliefs (cognition), in order to manage error costs (McKay & Dennett, 2009; McKay & Efferson, 2010). We discuss several hypotheses about why, in order to manage error costs, selection targets beliefs.
Males traditionally predominate at upper achievement levels. One general view holds that this is due only to various social factors such as the 'glass ceiling' and lack of female role models. Another view holds that it occurs partly because of innate ability differences, with more males being at upper ability levels. In the last few decades, women have become more achievement focused and competitive and have gained many more opportunities to achieve. The present study examined one intellectual domain, international chess, to quantify its gender differences in achievement and to see if these have been diminishing with the societal changes. Chess is a good test domain because it is a meritocracy, it has objective performance measures, and longitudinal data of a whole population are available. Performance ratings overall and in the top 10, 50 and 100 players of each sex show large gender differences and little convergence over the past three decades, although a few females have become high achievers. The distribution of performance ratings on the January 2004 list shows a higher male mean and evidence for more male variation, just as with traits such as height. Career patterns of players first on the list between 1985 and 1989 show that top males and females entered the list at about the same age but females tend to play fewer games and have shorter careers. In this domain at least, the male predominance is large and has remained roughly constant despite societal changes.
Intelligence is a core construct in differential psychology and behavioral genetics, and should be so in cognitive neuroscience. It is one of the best predictors of important life outcomes such as education, occupation, mental and physical health and illness, and mortality. Intelligence is one of the most heritable behavioural traits. Here, we highlight five genetic findings that are special to intelligence differences and that have important implications for its genetic architecture and for gene-hunting expeditions. (i) The heritability of intelligence increases from about 20% in infancy to perhaps 80% in later adulthood. (ii) Intelligence captures genetic effects on diverse cognitive and learning abilities, which correlate phenotypically about 0.30 on average but correlate genetically about 0.60 or higher. (iii) Assortative mating is greater for intelligence (spouse correlations ~0.40) than for other behavioural traits such as personality and psychopathology (~0.10) or physical traits such as height and weight (~0.20). Assortative mating pumps additive genetic variance into the population every generation, contributing to the high narrow heritability (additive genetic variance) of intelligence. (iv) Unlike psychiatric disorders, intelligence is normally distributed with a positive end of exceptional performance that is a model for ‘positive genetics’. (v) Intelligence is associated with education and social class and broadens the causal perspectives on how these three inter-correlated variables contribute to social mobility, and health, illness and mortality differences. These five findings arose primarily from twin studies. They are being confirmed by the first new quantitative genetic technique in a century—Genome-wide Complex Trait Analysis (GCTA)—which estimates genetic influence using genome-wide genotypes in large samples of unrelated individuals. Comparing GCTA results to the results of twin studies reveals important insights into the genetic architecture of intelligence that are relevant to attempts to narrow the ‘missing heritability’ gap.
This study examined sex differences in money beliefs and behaviours. Over 100,000 British participants completed two measures online, one of which assessed ‘‘money pathology’’ (Forman in Mind over money, Doubleday, Toronto, 1987), and the other four ‘‘money types’’, based on the emotional associations of money (Furnham et al. in Personal Individ Differ, 52:707–711, 2012). Nearly all measures showed significant sex differences with medium to large effect sizes, and with females exhibiting more ‘‘money pathology’’ than males. The biggest difference on the money types was on money being associated with generosity (money representing love) where men scored much lower than females, and autonomy (money representing freedom) where men scored higher than women. For men, more than women, money represented Power and Security. Men were more likely to be Hoarders while women did more emotional regulatory purchasing. Implications and limitations of this study are discussed.
We review recent evidence that suggests that hormonal contraceptives may influence the dynamics of sexual relationships and the human pair-bond. Hormonal contraception likely has positive effects on cementing the pair-bond by decoupling sex from conception. However, changes in women’s evolved mate preferences associated with initiation or discontinuation of hormonal contraception may alter attraction to her partner, with potentially negative consequences for relationship satisfaction. We describe the evidence for such changes produced by laboratory studies, including prospective experimental designs, and how the consequences of such changes are being explored beyond the laboratory. In view of the growing prevalence of modern hormonal contraceptive methods across the globe, further study of such effects is urgently required.
Although male height is positively associated with many aspects of mate quality, average height men attain higher reproductive success in US populations. We hypothesize that this is because the advantages associated with taller stature accrue mainly from not being short, rather than from being taller than average. Lower fertility by short men may be a consequence of their and their partner's lower scores on aspects of mate quality. Taller men, although they score higher on mate quality compared to average height men, may have lower fertility because they are more likely to be paired with taller women, who are potentially less fertile.
We analyzed data from The Integrated Health Interview Series (IHIS) of the United States (N = 165,606). Segmented regression was used to examine patterns across the height continuum.
On all aspects of own and partner quality, shorter men scored lower than both average height and taller men. Height more strongly predicted these aspects when moving from short to average height, than when moving from average to taller heights. Women of a given height who scored lower on mate quality also had shorter partners.
Shorter men faced a double disadvantage with respect to both their own mate quality and that of their spouses. Scores of taller men were only marginally higher than those of average height men, suggesting that being tall is less important than not being short. Although effect sizes were small, our results may partly explain why shorter and taller men have lower fertility than those of average stature.
The majority of research examining sex differences in risk-taking behavior focuses on overt physical risk measures in which failed risk attempts may result in serious injury or death. The present research describes sex differences in patterns of risk taking in day-to-day behavior among Dutch cyclists. Through three observational studies we test sex differences in risk taking in situations of financial risk (fines for failing to use bike lights, Study 1), theft risk (bike locking behavior, Study 2) as well as physical risk (risky maneuvers, Study 3). Results corroborate previous findings by showing that across these domains men are more inclined to take risks than women. We discuss how these findings might be used in an applied context.
Bruce J. Ellis, Aurelio J. Figueredo, Barbara H. Brumbach, Gabriel L. Schlomer (2009)
The current paper synthesizes theory and data from the field of life history (LH) evolution to advance a new developmental theory of variation in human LH strategies. The theory posits that clusters of correlated LH traits (e.g., timing of puberty, age at sexual debut and first birth, parental investment strategies) lie on a slow-to-fast continuum; that harshness (externally caused levels of morbidity-mortality) and unpredictability (spatial-temporal variation in harshness) are the most fundamental environmental influences on the evolution and development of LH strategies; and that these influences depend on population densities and related levels of intraspecific competition and resource scarcity, on age schedules of mortality, on the sensitivity of morbidity-mortality to the organism’s resource-allocation decisions, and on the extent to which environmental fluctuations affect individuals versus populations over short versus long timescales. These interrelated factors operate at evolutionary and developmental levels and should be distinguished because they exert distinctive effects on LH traits and are hierarchically operative in terms of primacy of influence. Although converging lines of evidence support core assumptions of the theory, many questions remain unanswered. This review demonstrates the value of applying a multilevel evolutionary-developmental approach to the analysis of a central feature of human phenotypic variation: LH strategy.