Individuals high in narcissism have “thin skins” and are prone to aggression when they are provoked; these results suggest that narcissism is an important risk factor for aggression and violence

Kjærvik, S. L., & Bushman, B. J. (2021). The link between narcissism and aggression: A meta-analytic review. Psychological Bulletin, May 2021. https://doi.org/10.1037/bul0000323

Abstract: This meta-analytic review examines the link between narcissism and aggression, and whether the link is stronger under provocation conditions. A total of 437 independent studies were located, which included 123,043 participants. Narcissism was related to both aggression (r = .26, [.24, .28]) and violence (r = .23, [.18, .27]). As expected, the narcissism-aggression link was stronger under provocation conditions (r = .29, [.23, .36]) than under no provocation conditions (r = .12, [.05, .18]), but was even significant in the absence of provocation. Both “normal” and “pathological” narcissism were related to aggression. All three dimensions of narcissism (i.e., entitlement, grandiose narcissism, vulnerable narcissism) were related to aggression. Narcissism was related to all forms of aggression (i.e., indirect, direct, displaced, physical, verbal, bullying), and to both functions of aggression (i.e., reactive, proactive). The relation between narcissism and aggression was significant for males and females, for people of all ages, for students and nonstudents, and for people from individualistic and collectivistic countries. Significant results were obtained in experimental, cross-sectional, and longitudinal studies, in published and unpublished studies, and in studies that assessed aggression using different types of measures (i.e., self-report, other-report, observation). Overall results were robust to publication bias and the presence of outliers. Theoretically, these results indicate that provocation is a key moderator of the link between narcissism and aggression. Individuals high in narcissism have “thin skins” and are prone to aggression when they are provoked. Practically, these results suggest that narcissism is an important risk factor for aggression and violence.

Gut reactions were harsher and behavioral intentions linked to action were stronger when the error was made by an algorithm compared to human error; irrespective of error severity or info about algorithm maturity

To err is human, not algorithmic – Robust reactions to erring algorithms. Laetitia A. Renier, Marianne Schmid, Mast Anely Bekbergenova. Computers in Human Behavior, May 30 2021, 106879. https://doi.org/10.1016/j.chb.2021.106879

Highlights

• Reactions toward erring algorithms go beyond algorithm aversion.

• Gut reactions were harsher and behavioral intentions linked to action were stronger when the error was made by an algorithm.

• Justice cognitions were weaker when the error was made by an algorithm.

• Observed effects were immune to the domain of use, the severity of the error, and information about algorithm maturity.

Abstract: When seeing algorithms err, we trust them less and decrease using them compared to after seeing humans err; this is called algorithm aversion. This paper builds on the algorithm aversion literature and the third-party reactions to mistreatment model to investigate a wider array of reactions to erring algorithms. Using an experimental design deployed with a vignette-based online study, we investigate gut reactions, justice cognitions, and behavioral intentions toward erring algorithms (compared to erring humans). Our results show that when the error was committed by an algorithm (vs. a human), gut reactions were harsher (i.e., less acceptance and more negative feelings), justice cognitions weaker (i.e., less blame, less forgiveness, and less accountability), and behavioral intentions stronger. These results remain independent of factors such as the maturity of the algorithms (better than or same as human performance), the severity of the error (high or low), and the domain of use (recruitment or finance). We discuss how these results complement the current literature thanks to a robust and more nuanced pattern of reactions to erring algorithms.

Keywords: Algorithm aversionArtificial intelligenceErrorReactionsPerceptionThird-party

An honesty oath leads to more truth telling; liars need more time to decide under oath

How the honesty oath works: Quick, intuitive truth telling under oath. Tobias Beck. Journal of Behavioral and Experimental Economics, May 29 2021, 101728. https://doi.org/10.1016/j.socec.2021.101728

Highlights

• An honesty oath leads to more truth telling

• The additional truth tellers under oath decide very fast

• Liars need more time to decide under oath

• The oath reduces the extent of strategic reasoning in the decision whether to tell the truth or not

• The honesty oath works by making the decision to tell the truth more intuitive and less deliberate

Abstract: This study analyzes the workings of oath-taking when the decision about lying requires strategic thinking. In a laboratory experiment, the oath leads to more truth telling, but it does not make liars reduce the sizes of their lies. While truth tellers decide faster due to the oath, liars need more time to decide under oath. By analyzing players’ beliefs about their co-players’ mistrust, I find that the oath reduces the extent of strategic reasoning in the decision whether to tell the truth or not. These findings are consistent with the conjecture that the honesty oath works by making the decision to tell the truth less deliberate and more intuitive.

Keywords: Honesty oathStrategic deceptionTruth tellingSize of the lieLaboratory experiment

People often overestimate their past mobility, strongly believe in their future one, & think that The American Dream is alive for them and their families more than it is for others or the country as a whole

The psychology of lay beliefs about economic mobility. Shai Davidai, Margaux N. A. Wienk. Social and Personality Psychology Compass, May 28 2021. https://doi.org/10.1111/spc3.12625

Abstract: Although economic mobility is an objectively defined term, lay beliefs about mobility—the configuration of ideas and attitudes about economic mobility that is not necessarily grounded in economic data—are often formed in a subjective manner. Drawing on research from the United States and beyond, we propose a novel framework for understanding how people construe, think about, and understand economic mobility. We highlight the importance of systematically examining the type, time frame, trajectory, and target of mobility that people have in mind for understanding when they most and least strongly believe in it. In addition, our framework offers a conceptual roadmap for examining the factors that influence lay beliefs about mobility, including individual differences in these lay beliefs and their important downstream consequences. Finally, we outline several important open questions that are highlighted by our framework as a guide for future research on lay beliefs about economic mobility.

Granddaughter’s intimacy with maternal grandmothers was significantly higher and with paternal grandfathers significantly lower than with other grandparents than with other grandparents

Which grandparent is more intimate? The effects of the gender of grandchildren. Mengjie Tu, Hongpo Zhang, Yafei Guo, Lin Zhang, Xinhui Wei & Quanlei Yu. Current Psychology, May 25 2021. https://link.springer.com/article/10.1007/s12144-021-01890-6

Abstract: Mothers have almost 100% certainty of their relationship with their offspring, but fathers face paternal uncertainty, which affects not only parental investment but also grandparents’ investment in grandchildren. However, due to Chinese patriarchal culture and preference for sons, grandparents may give their grandchildren different investments by gender. To explore the psychological and behavioral mechanisms of grandparents’ emotional investment in grandchildren from both cultural and evolutionary perspectives, this study collected data from 642 Chinese participants who had impressions of all four grandparents and measured their relationships with their grandparents and other demographic variables. After controlling for the number of grandchildren, participant’s age, region, etc., a significant interaction between the grandchild’s gender and grandparent categories was found. Simple effect analysis and post-hoc analysis showed significant differences in grandsons’ intimacy with maternal grandmothers and grandfathers, but no other grandparents, while granddaughter’s intimacy with maternal grandmothers was significantly higher and with paternal grandfathers significantly lower than with other grandparents, and there were no other significant differences. Those results support human psychology and behavior are jointly influenced by evolution and culture.

Millions of People's Location Data Revealed a 'Universal' Pattern In Study: The universal visitation law of human mobility

The universal visitation law of human mobility. Markus Schläpfer, Lei Dong, Kevin O’Keeffe, Paolo Santi, Michael Szell, Hadrien Salat, Samuel Anklesaria, Mohammad Vazifeh, Carlo Ratti & Geoffrey B. West. Nature, volume 593, pages522–527. May 26 2021. https://www.nature.com/articles/s41586-021-03480-9

Abstract: Human mobility impacts many aspects of a city, from its spatial structure1,2,3 to its response to an epidemic4,5,6,7. It is also ultimately key to social interactions8, innovation9,10 and productivity11. However, our quantitative understanding of the aggregate movements of individuals remains incomplete. Existing models—such as the gravity law12,13 or the radiation model14—concentrate on the purely spatial dependence of mobility flows and do not capture the varying frequencies of recurrent visits to the same locations. Here we reveal a simple and robust scaling law that captures the temporal and spatial spectrum of population movement on the basis of large-scale mobility data from diverse cities around the globe. According to this law, the number of visitors to any location decreases as the inverse square of the product of their visiting frequency and travel distance. We further show that the spatio-temporal flows to different locations give rise to prominent spatial clusters with an area distribution that follows Zipf’s law15. Finally, we build an individual mobility model based on exploration and preferential return to provide a mechanistic explanation for the discovered scaling law and the emerging spatial structure. Our findings corroborate long-standing conjectures in human geography (such as central place theory16 and Weber’s theory of emergent optimality10) and allow for predictions of recurrent flows, providing a basis for applications in urban planning, traffic engineering and the mitigation of epidemic diseases.

Popular version: Millions of People's Location Data Revealed a 'Universal' Pattern In Study https://www.vice.com/amp/en/article/epnzkm/millions-of-peoples-location-data-revealed-a-universal-pattern-in-study

Wisdom: When thinking about others, we often take a perspective of an impartial observer, a third person viewing the events from afar; it seems a good idea to work on our issues from a distant observer perspective

Grossmann, Igor. 2021. “Wisdom: Situational, Dispositional, or Both?.” PsyArXiv. May 28. doi:10.31234/osf.io/q2whm

Abstract: Some people think wisdom is a stable and invariable individual disposition. Others view wisdom as deeply embedded in culture, experiences, and situations, and treat these features as mutually making up wisdom. Who is right and what are the implications for measurement, training and the fundamental (essentialist vs. constructivist) nature of wisdom itself? In this chapter, we will review evidence concerning the dispositional versus situational approaches to study wisdom. Even though main features of wisdom show some stability, there is also a profound and systematic variability in response to situational demands. We will also learn about a novel theoretical framework, conceptualizing dispositions as a distribution of situation-specific responses, thereby resolving the dispositional versus situational debate on the nature of wisdom. Drawing on these insights, we will conclude by reflect on recommendations for best measurement practices and ways to boost and train wisdom in everyday life.

Boosting and training wisdom

One of the most exciting implications of cross-situational variability in wisdom is that we can possibly shape situations to our benefit. Here, the insight about wisdom being lower when dealing with personal issues appears troublesome: In many domains of our lives, we cannot always defer decisions to someone else. What to do? As we discussed earlier when introducing the idea of naïve realism in perception of reality, people tend to subjectively represent and construct the events they encounter ⁸. The notion of subjective construal can help shed possible light on the difference in wisdom when reflecting on person- and non-person-centric situations. Ethan Kross and I reasoned that the reason wisdom appeared heighted in reflection on non-personal challenges concerns a particular vantage point one adopts when construing other people’s problems compared to personal problems. When thinking about others, we often take a perspective of an impartial observer, a third person viewing the events from a far. In contrast, when we reflect on personal issues we typically do so from an immersed, first-person perspective. If this difference in the subjective vantage point is elemental for the self-other asymmetry in manifest wisdom, it may be possible to boost wisdom in reflection on personal issues by construing personal situations as an “impartial observer.”

We first sought to test this idea in the context of job prospects at the peak of "great recession" in the U.S., asking college seniors, none of whom had a secured job at this point, to consider their future career prospects ⁴³. Participants were randomly assigned to two conditions. In one condition, we instructed participants to reflect on their job prospects from a perspective of a "distant observer," envisioning the situation unfolding from a far. In the control condition, seniors envisioned the situation unfolding before their own eyes. What we found is that compared to the control group, the “distant observer” instructions prompted greater wisdom – greater recognition of limits of their knowledge and consideration of things may unfold and change. In follow-up set of experiments, we showed equivalent results when instructing participants to reflect on a polarized political issue at a peak of 2008 U.S. presidential election ⁴³, trust and infidelity conflicts ¹⁰, and personal autobiographical experiences – i.e., recent unresolved conflicts people experienced in their own lives ^44,45. In each case, linguistic and temporal prompts promoting a distant observer vantage point (e.g., by using a third-person language “he”/”she” or perspective of “one year from now”) fostered wisdom (recognition of the limits of one's knowledge and recognition of change) in reflections on hypothetical and autobiographical issues compared to prompts promoting an immersed vantage point (e.g., by using a first-person language “me”/”mine” or a perspective of “here and now”). Moreover, using this manipulation, we were able to attenuate the self-other asymmetry discussed above. That is, observer vantage point led to greater wisdom for both personal and a friend’s problems, reducing self-other asymmetry ^{10; Studies 2-3}. It appears that experimental instructions altered the perception of the situation—from exclusively self-focused to a situation considering viewpoints of other persons involved, in turn recreating wisdom-enhancing contexts in one's mind. Overall, it appears that a wide range of construal-altering instructions (see Figure 4) increases participants' ability for applied central features of wisdom in hypothetical and real-world situations, both in the context of interpersonal and intergroup conflicts.

fig 4

Can the distanced observer construal be trained to promote changes in wisdom over time? Building on the insights from the contextual view of wisdom, my colleagues and I decided to address this question ⁴⁶. Given that people experience a range of issues in their lives, we reasoned that an effective shift in subjective construal toward a vantage point of an impartial observer requires repeated practice of wisdom-enhancing strategies over time. In turn, practice-driven shifts in subjective construal should promote greater wisdom after the practice. We tested this idea in a set of randomized control trial (RCT) intervention. In each study, participants reflected on their interpersonal conflicts twice – before and after the intervention, and we analyzed their reflections for presence of wisdom-related themes. In-between these measurement points, participants were randomly assigned to the third-person intervention condition or the first-person control condition (in the second study we also added no instruction control condition). In each condition, participants were instructed to keep a diary, each day writing a short reflection on the most significant (positive or negative) issue of the day. Based on the earlier experimental work, in the intervention condition participants had to write the diary using third-person language, reflecting on the event from an observer perspective. In the control condition(s), participants wrote their diary in a first-person, as one would typically do. Figure 5 shows the results we saw in the first study, which demonstrate that this month-long intervention impacted a range of features of wisdom, resulting in post-intervention growth in wisdom in the third-person condition compared to the control condition. These results were statistically accounted by a shift toward more inclusive subjective construal of the interpersonal conflicts participants reflected on in the experimental conditions. In the spirit of humility, it is worth highlighting that these training results are preliminary and require further replications and extensions to other cultures. None the less, they are encouraging, for the first time providing empirical support from randomized control trials for training-based shifts in wisdom over time.

fig 5

Larger is not better: No mate preference by European Common Frog (Rana temporaria) males; plus large rate of failures to mate

Larger is not better: No mate preference by European Common Frog (Rana temporaria) males. Carolin Dittrich, Oliver Roumldel. bioRxiv, May 28 2021. https://doi.org/10.1101/2021.05.28.446140

Abstract: According to classical sexual selection theory, females are the choosy sex in most species. Choosiness is defined as the individual effort to invest energy and time to assess potential mates. In explosive breeding anurans, high intrasexual competition between males leads to a sexual coercion ruled mating system, where males could have evolved preferences for specific female traits. In the current study, we tested male mating preference in the explosive breeding European Common Frog without intrasexual competition. We hypothesized that males show preferences towards larger female body size in the absence of male competition. We conducted mate choice experiments, placing a male and two differently sized females in a box and recorded their mating behavior. Males did not show any preference considering female body size, neither in the attempt to grab a female nor during the formation of pairs. We witnessed a high failure rate of male mating attempts, which might make the evolution of mate choice too costly. However, small males are faster in attempting females, which could be an alternative strategy to get access to females, because their larger competitors have an advantage during scramble competition. Nonetheless, in successfully formed pairs, the females were on average larger than the males, an observation which deviated from our null-model where pairs should be of similar size if mating would be random. This indicates that selection takes place, independent from male mating preference or scramble competition.

26 Introduction

27 Research on sexual selection, exploring the mechanisms that lead to female/male mate choice and the evolution of 

28 different mating systems that facilitate non-random mating, has increased considerably in recent years (Janetos 1980; 

29 Ryan and Keddy-Hector 1992; Paul 2002; Edward and Chapman 2011). Studies addressing the theory of sexual 

30 selection revealed that females are the choosy sex in most species. This is mainly based on one assumption, the 

31 evolution of anisogamy, where males produce many small (cheap) gametes and females less but larger (expensive) 

32 gametes. Thus, females invest more energy in the production of eggs than males invest in the production of sperm 

33 (Trivers 1972). In consequence, reproduction is more costly to females and they should choose the 'fittest' male to 

34 mate with. This includes those with the best possible genes to improve her offspring’s fitness and/or those who can 

35 provide vital resources (e.g. territory, nesting place, food, parental care) to increase offspring survivability and 

36 attractiveness, thereby increasing the female´s personal fitness (Fisher 1958; Hedrick 1988; Møller and Alatalo 

37 1999). Here, choosiness is defined as an individual’s active effort to invest energy and time to assess potential mates, 

38 whereas preference is defined as an intrinsic, passive attractiveness towards specific traits of the opposite sex 

39 (Jennions and Petrie 1997; Cotton et al. 2006). However, female preferences can be overridden by dominant 

40 intrasexual competition (Qvarnström and Forsgren 1998; Härdling and Kokko 2005; Formica et al. 2016). 

41 Preferences can enhance the evolution of different mating strategies and tactics to increase reproductive output with 

42 behavioral plasticity; depending on sex, age, physiological state or operational sex ratio (Parker 1982; Gross 1996). 

43 Nevertheless, newer studies suggest that males can be choosy too, if mate availability is high and simultaneous 

44 sampling possible (Barry and Kokko 2010), if there is variation in female quality/fecundity (Krupa 1995; Johnstone 

45 et al. 1996), and if the benefits of choosing between females is higher then the costs associated with assessing 

46 females (Edward and Chapmann 2011, and references therein). Some prerequisites are the presence of males’ ability 

47 to detect differences and a preference for particular female traits. Body size can be such a trait, i.e. indicating 

48 longevity based on good genes which could be heritable (Kokko and Lindström 1996; Møller and Alatalo 1999). 

49 However, body size usually is based on a variety of genes and environmental processes, but might simply indicate 

50 higher fecundity (Peters 1986; Shine 1988; Nali et al. 2014). Mating with a larger female thus may increase a male’s 

51 individual fitness. A male’s choice however, should not only be based on such trivial correlation, it will be impacted 

52 by trade-offs concerning its mating chances, and thus individual males indeed may follow very different strategies to 

53 access females. Some examples of male tactics are satellite males, usually being smaller than their competitors (Arak 

54 1983; Halliday and Tejedo 1995), mate-guarding (Parker 1974), prudent mate choice (Fawcett and Johnstone 2003; 

55 Härdling and Kokko 2005), clutch piracy (Vieites et al. 2004) or even functional necrophilia (Izzo et al. 2012). 

56 Mating systems in amphibians are diverse, and apart from environmental parameters, mostly depend on female 

57 availability over time (Wells 2007). In frog and toad species (anurans) with long breeding periods (prolonged 

58 breeders) female mate choice seems to be the rule (Wells 1977). At any given time, a few females actively choose 

59 among many calling males, often based on call characteristics (Toledo et al. 2015; Ryan et al. 2019), the quality of 

60 defended territories, or the availability of other resources to judge the males (Howard 1978; Kirkpatrick and Ryan 

61 1991; Kokko and Jennions 2008; da Rocha et al. 2018). In lek-breeding anurans, the males aggregate in displaying 

62 arenas that do not contain any resources required by females. Females visiting these arenas 'sample' several males 

63 and choose a male to mate with (Bourne 1992). In lek-mating systems the operational sex ratio is highly skewed 

64 towards males and individual males are not able to monopolize females, leading to higher intrasexual competition 

65 (Emlen and Oring 1977). In contrast, in species with a short breeding period (explosive breeders) males are actively 

66 searching for mates and engage in direct male-male competition over the arriving females. Explosive breeding is 

67 characterized by an almost equal operational sex ratio, synchronized receptiveness of females and low sexual 

68 selection (Emlen and Oring 1977). In theory all males are able to mate and reproduce, but larger/more dominant 

69 males have an advantage to access and dominate receptive females during scramble competition leading to a 

70 variation in male mating success (Berven 1981; Olson et al. 1986; Höglund 1989; Vagi and Hettyey 2016). 

71 Therefore, some males are considered to sexually dominate the females in explosive breeding systems, leaving little 

72 room for male and female mate choice if the cost for mate sampling are too high (Dechaume-Moncharmont et al. 

73 2016). Nevertheless, male mate preferences could have evolved in explosive breeders, because female fecundity 

74 highly dependents on female body size in most anuran species (Krupa 1995; Nali et al. 2014). Simultaneous 

75 sampling of preferred females might be particular possible during the peak mating time because female availability 

76 should then be highest (Arntzen 1999; Barry and Kokko 2006). All males should prefer larger females to increase 

77 their own fitness according to adaptation theory, although preferences could be obscured by high intrasexual 

78 competition. On the other hand, costs associated with mate choice depend on male density and the frequency of 

79 different mating tactics within a breeding aggregation (Arak 1983; Höglund and Robertson 1988), as well as for 

80 instance male’s individual predation risk (Magnhagen 1991; Bernal et al. 2007), all factors which may vary already 

81 during a short breeding season (Olson et al. 1986; Vojar et al. 2015). 

82 In this study, we investigate the mating preference of the European Common Frog (Rana temporaria) because it is an 

83 excellent example of an explosive breeder with male-male competition. Although former studies suggest a lack of 

84 male mate preferences in this species (Elmberg 1991), we observed non-random mating by body size and found 

85 indications of male mate preference and different mating tactics in former experiments (Dittrich et al. 2018). Larger 

86 females were paired more frequently than smaller ones and smaller sized males showed a different mating tactic to 

87 get access to females (Dittrich et al. 2018). Here, we hypothesize that all males will prefer larger females 

88 independent of their own body size, when intrasexual competition is absent and males are presented to differently 

89 sized females. Additionally, we predict small males to be faster in attempting a female to increase their chances to 

90 keep an exclusive access to the female during scramble competition

The Cartesian Folk Theater: People believe that consciousness happens in a single, confined area (vs. multiple dispersed areas) in the human brain, and that it (partly) happens after the brain finished analyzing all available information(partly) happens after the brain finished analyzing all available information

Forstmann, Matthias, and Pascal Burgmer. 2021. “The Cartesian Folk Theater: People Conceptualize Consciousness as a Spatio-temporally Localized Process in the Human Brain.” PsyArXiv. May 28. doi:10.31234/osf.io/9txzd

Abstract: The present research (total N = 2,057) tested whether people’s folk conception of consciousness aligns with the notion of a “Cartesian Theater” (Dennett, 1991). More precisely, we tested the hypotheses that people believe that consciousness happens in a single, confined area (vs. multiple dispersed areas) in the human brain, and that it (partly) happens after the brain finished analyzing all available information. Further, we investigated how these beliefs are related to participants’ neuroscientific knowledge as well as their reliance on intuition, and which rationale they use to explain their responses. Using a computer-administered drawing task, we found that participants located consciousness, but not unrelated neurological processes (Studies 1a & 1b) or unconscious thinking (Study 2) in a single, confined area in the prefrontal cortex, and that they considered most of the brain not involved in consciousness. Participants mostly relied on their intuitions when responding, and they were not affected by prior knowledge about the brain. Additionally, they considered the conscious experience of sensory stimuli to happen in a spatially more confined area than the corresponding computational analysis of these stimuli (Study 3). Furthermore, participants’ explicit beliefs about spatial and temporal localization of consciousness (i.e., consciousness happening after the computational analysis of sensory information is completed) are independent, yet positively correlated beliefs (Study 4). Using a more elaborate measure for temporal localization of conscious experience, our final study confirmed that people believe consciousness to partly happen even after information processing is done (Study 5).

Increasing Population Densities Predict Decreasing Fertility Rates over Time: A 174-nation Investigation

Rotella, Amanda M., Michael E. W. Varnum, PhD, Oliver Sng, and Igor Grossmann. 2020. “Increasing Population Densities Predict Decreasing Fertility Rates over Time: A 174-nation Investigation.” PsyArXiv. August 5. doi:10.31234/osf.io/zpc7t

Abstract: Fertility rates have been declining worldwide over the past fifty years, part of a phenomenon known as “the demographic transition.” Prior work suggests that this decline is related to population density. In the present study, we draw on life history theory to examine the relationship between population density and fertility across 174 countries over 69 years (1950 to 2019). We find a robust association between density and fertility over time, both within- and between-countries. That is, increases in population density are associated with declines in fertility rates, controlling for a variety of socioeconomic, socioecological, geographic, population-based, and female empowerment variables. We also tested predictions about environmental boundary conditions. In harsher living conditions (e.g., higher homicide or pathogen rates), the effect of increased population density on fertility rates was attenuated. The density-fertility association was also moderated by religiousness and strength of social norms, where the relationship between density and fertility was attenuated in countries with high religiosity and strong social norms. We discuss why and when changes in population density may influence fertility rates and the broader implications of this work.

Cultural evolution of emotional expression in 50 years of song lyrics

Cultural evolution of emotional expression in 50 years of song lyrics. Charlotte O. Brand, Alberto Acerbi, Alex Mesoudi. Evolutionary Human Sciences , Volume 1 , 2019 , e11. Nov 7 2019. https://doi.org/10.1017/ehs.2019.11

Abstract: Popular music offers a rich source of data that provides insights into long-term cultural evolutionary dynamics. One major trend in popular music, as well as other cultural products such as literary fiction, is an increase over time in negatively valenced emotional content, and a decrease in positively valenced emotional content. Here we use two large datasets containing lyrics from n = 4913 and n = 159,015 pop songs respectively and spanning 1965–2015, to test whether cultural transmission biases derived from the cultural evolution literature can explain this trend towards emotional negativity. We find some evidence of content bias (negative lyrics do better in the charts), prestige bias (best-selling artists are copied) and success bias (best-selling songs are copied) in the proliferation of negative lyrics. However, the effects of prestige and success bias largely disappear when unbiased transmission is included in the models, which assumes that the occurrence of negative lyrics is predicted by their past frequency. We conclude that the proliferation of negative song lyrics may be explained partly by content bias, and partly by undirected, unbiased cultural transmission.

Discussion

We analysed the emotional content of song lyrics in over 160,000 songs spanning the years 1965–2015. We found that the frequency of negative words increased over time, whilst the frequency of positive words decreased over time, and asked whether these patterns could be attributed to cultural transmission biases such as success bias, prestige bias, content bias or unbiased transmission. In the billboard dataset, containing top-100 songs from 1965 to 2015, we found an effect of unbiased transmission on positive lyrics, and an effect of content bias on negative lyrics. For the larger mxm databases we only found weak effects of unbiased transmission for both negative and positive lyrics.

The effects we found in all models are extremely small. This is partly because we analysed the data on the scale of each word, negating any need for averaging over lyrics and songs. Thus, the relative increase or decrease in the log odds is understandably small. Furthermore, our implementation of transmission biases is necessarily indirect and simplified given that we lack direct observations of song lyrics being copied. It is therefore unsurprising that the effects vastly reduced or disappeared when controlling for unbiased transmission, given how many other factors must be at play in the generation of song lyrics, both directional biases such as those we explored here and random processes (Bentley et al. 2007). For example, prestige can be realised in myriad ways (Jiménez and Mesoudi 2019), particularly in the music industry. The effect of various recording companies, the extent of media attention outside of the charts and the amount of money spent on music promotion may all play a significant role in an artist's apparent prestige, and is not necessarily restricted to the content of their music. Our implementation of ‘prestige’ as predominance in the charts therefore only captures one specific aspect of musical prestige.

The effect of unbiased transmission is, however, the largest and most consistent in all of our models. This result suggests there may be an effect of random drift, or random copying, in the emotional content of song lyrics over time. This is consistent with previous work showing that random copying can explain changes in the popularity of dog breeds, baby names and popular music (Bentley et al. 2007; Hahn and Bentley 2003), as well as archaeological pottery and technological patents (Bentley et al. 2004). Thus, rather than song-writers being influenced by the most prestigious or successful artists, they may simply be influenced by the emotional content of any of the available song lyrics in the previous timestep, which may happen to increase in negativity or decrease in positivity owing to small fluctuations. As in previous work, our results do not provide evidence of literal random copying by individuals as we do not have direct access to individual's copying decisions. Instead, random drift is posed as a baseline against which to compare evidence of other copying biases. It is possible that the population-wide patterns are not a result of unanimous random copying, but owing to a multitude of idiosyncratic causes that collectively cancel each other out to create the appearance of random copying (Hoppitt and Laland 2013). In this sense, any small fluctuation in negative words owing to a particular historical event, or owing to the emergence of a more negatively biased genre, may have caused an initial increase in negative lyrics, which became exacerbated by random drift.

The presence of a content bias in the likelihood of negative lyrics occurring in the billboard songs is noteworthy. This result suggests that songs with more negative lyrics are more successful in general, perhaps reflecting either a general negativity bias (Bebbington et al. 2017; Fessler et al. 2014) or an art-specific, or music-specific, negativity bias. Similar trends favouring negative emotions vs positive ones in other artistic domains support our finding. As mentioned above, Dodds and Danforth (2010) documented a decrease in frequency of positively valenced words, and an increase in negatively valenced ones in pop song lyrics (a similar result was found in DeWall et al. 2011). Morin and Acerbi (2017) found a similar pattern in centuries of literary fiction, with a general decrease in the frequency of words denoting emotions, explained by a decrease in words denoting positive emotions, whereas the frequency of negative words remained constant. It is worth noting that we were unable to look for content bias (with our implementation) in the mxm data as there was no ranking system. One possible way of determining the popularity or use of a song could be to look at how many times, or how often, its lyrics are searched for, and whether this correlates with negative content.

In general, the idea that negative emotions would be privileged in art is consistent with the hypothesis that artistic expressions may have an adaptive function, in particular as simulation of social interactions (Mar and Oatley 2008). According to this view, developed with literary fiction in mind but potentially generalisable to other expressive forms, art would provide hypothetical scenarios where we can test and train, with no risk, our cognitive and emotional reactions. From this perspective, simulating negative events is more useful than simulating positive ones (Clasen 2017; Gottschall 2012). Art expressing negative emotions, in addition, may hold more value for audiences seeking comfort from the knowledge that others also experience negative emotions. Indeed, studies have shown that people underestimate the prevalence of others’ negative emotions, and this underestimation exacerbates loneliness and decreases life satisfaction (Jordan et al. 2011). Furthermore, suppressing rather than reappraising negative emotions decreases self-esteem and increases sadness (Nezlek and Kuppens 2008)(Nezlek & Kuppens, 2008). This hypothesis is worth investigating in future research.

Our varying effects models suggested that most of the variation lay between artists. However, genre also showed considerable variation. We were unable to control for genre in the billboard data as genre information was not available with this dataset. This could provide a partial explanation for the differing results between the billboard and mxm datasets; indeed, Dodds and Danforth (2010) attributed the decrease in emotional valence within pop song lyrics to the emergence of more negative genres such as heavy metal and punk. Future work investigating the variation of emotional expression between different genres of music would be valuable. A further limitation of this study is that we restricted our analysis to comparing the content of each song with that of the songs from the previous three years of songs. Mechanistically this suggests that songs that are currently in the charts influence song-writers who are writing within three years of chart success, assuming that the time it takes to get from the song-writing process to chart success is three years or less. It is possible that these effects are stronger or weaker at different time points, such as within one or five years of chart success. Furthermore, although we controlled for artist, many songs in the billboard charts are in fact written by specially designated song-writers, such as Max Martin.

Overall this research contributes to the growing body of work attempting to quantitatively study trends in the domain of music (Youngblood 2019; Savage 2019; Mauch et al. 2015; Ravignani et al. 2017). Our starting result of an increase in negative emotions and decrease in positive ones in song lyrics is paired with similar findings regarding acoustic qualities. Using the same Billboard top-100 songs that we analysed, Schellenberg and von Scheve (2012) found an increase in minor mode and a decrease in the average tempo, which indicates that the songs become more sad-sounding through time. This seems to be part of a longer trend in Western classical music, where the use of the minor mode increased over a 150-year period from 1750 to 1900 (Horn and Huron 2015). The relationship between minor tone and negative valence of lyrics has been also studied, and confirmed, quantitatively (Kolchinsky et al. 2017). Analogously, studying more than 500,000 songs released in the UK between 1985 and 2015, Interiano et al. (2018) found a similar decrease in ‘happiness’ and ‘brightness’, coupled with a slight increase in ‘sadness’ (these high-level features result from algorithms analysing low-level acoustic features, such as the tempo, the tonality, etc.). They also found the puzzling result that, despite a general trend towards sadder songs, the successful hits are, on average, happier than the rest of the songs. In the same way, whereas we found that the higher the position in the billboard chart the more negative a song is, billboard songs are as a whole more positive than the songs in the mxm dataset, which contains more (and less successful) songs.

In this study we used cultural evolutionary theory to try to explain patterns in one of the most pervasive of human cultural practices, music production. More specifically, we tried to detect whether any particular transmission bias best explained the changing patterns of emotional expression over time. We conclude that, although we found weak evidence of success and prestige biases, these were overwhelmed by an effect for unbiased transmission. The presence of a content bias for negative lyrics remained, and this may be a contributing factor to the increasing in negative lyrics over time. A potential explanation for these results is that a multitude of transmission biases and other causes are at play. It is likely that small shifts, for example owing to historical events or the emergence of particular genres, may have nudged the production and transmission of negative and positive lyrics in opposite directions, and random copying exacerbated this trajectory. These possibilities should be explored more in future work. Overall, the exercise of precisely analysing large datasets to explain cultural change, if refined on relatively benign cultural trends such as pop music, could eventually be more expertly applied to areas of greater societal importance and impact, such as shifts in political beliefs or moral preferences.

Opinion: Expecting mothers to care for children with little support, while expecting fathers to provide for their families with little support, is likely to lead to adverse health consequences for mothers, fathers & children

Opinion: The male breadwinner nuclear family is not the ‘traditional’ human family, and promotion of this myth may have adverse health consequences. Rebecca Sear. Royal Society Philosophical Transactions B, June 21 2021, Volume 376, Issue 1827. https://doi.org/10.1098/rstb.2020.0020

Abstract: The importance of social support for parental and child health and wellbeing is not yet sufficiently widely recognized. The widespread myth in Western contexts that the male breadwinner–female homemaker nuclear family is the ‘traditional’ family structure leads to a focus on mothers alone as the individuals with responsibility for child wellbeing. Inaccurate perceptions about the family have the potential to distort academic research and public perceptions, and hamper attempts to improve parental and child health. These perceptions may have arisen partly from academic research in disciplines that focus on the Western middle classes, where this particular family form was idealized in the mid-twentieth century, when many of these disciplines were developing their foundational research. By contrast, evidence from disciplines that take a cross-cultural or historical perspective shows that in most human societies, multiple individuals beyond the mother are typically involved in raising children: in evolutionary anthropology, it is now widely accepted that we have evolved a strategy of cooperative reproduction. Expecting mothers to care for children with little support, while expecting fathers to provide for their families with little support, is, therefore, likely to lead to adverse health consequences for mothers, fathers and children. Incorporating evidence-based evolutionary, and anthropological, perspectives into research on health is vital if we are to ensure the wellbeing of individuals across a wide range of contexts.

---

What are the implications of a male breadwinner isolated nuclear family norm for health and wellbeing?

So there is considerable evidence that the idea that the ‘traditional’ human family is an isolated nuclear family, in which mothers are solely responsible for childcare and fathers solely responsible for providing for their families, is a myth. Isolated nuclear families, who raise children without help beyond the parental unit, barely seem to exist at all, even in 20th or 21st century Western societies, and male breadwinning is both rare and novel in our history. Myths about the ‘traditional’ family, and what ‘traditional’ maternal and paternal roles should look like, are likely to have real world implications. The assumption that mothers are primarily responsible for childrearing, that they should sacrifice themselves to invest intensively and over a long period in their children, may put considerable 12 pressure on women to behave in ways compatible with this difficult-to-attain, and novel, ideal of motherhood (Budds, this issue). Particularly damaging may be the idea that mothers should be able to cope with relatively little support. Research has shown that new mothers in the UK spend a significant proportion of their time alone with their infants (one study found 38% of mothers spent >8 hours a day alone, and 34% between 4-8 hours [80]). This is a situation which appears to be less than desirable in a social species which relies on cooperation to raise children, and on social learning for developing skills in a wide range of behaviours including parenting. Such isolation and the expectation that mothers should cope with little support is not likely to provide ideal childrearing conditions for either mother or child; for example, prompting maternal guilt where mothers feel they are not living up to this ideal [81,82], increased rates of postnatal depression [83] and decreased breastfeeding [84] in the absence of support, and other negative effects on mother’s wellbeing [85]. Assumptions about the adverse effect of the ‘breakdown’ of marriages, which idealise the nuclear family as the best way to raise children, and blame adverse child outcomes on the absence of such a family structure, have also led to government interventions aimed at persuading couples to marry rather than cohabit in the US [86]. These interventions tend to focus on socioeconomically disadvantaged groups because such groups have lower rates of marriage than more advantaged groups. A belief underlying these interventions appears to be that if disadvantaged groups can be made to form marital relationships which mirror the family structure of advantaged groups, then their disadvantage will melt away. Such interventions have attracted criticism, because a more effective way of reducing “bad family outcomes” is likely to be to tackle economic disadvantage itself, rather than a marker of disadvantage such as cohabitation [87]. These marriage interventions also don’t work. Public health initiatives around maternal and child health in lower and middle income countries typically also assume a default nuclear family structure in which mothers are largely responsible for the health of their children – this excludes vital support structures such as grandmothers (see Daniele, this issue). There are even some perceptions in global health that grandmothers are the ‘guardians of tradition’ [88] and that, if they have a role at all, it is a role which has the potential for negative maternal and health outcomes given that the advice of older women may contradict that of public health professionals. This echoes some of the findings from the literature on grandparental investment which suggests that input from grandparents may not always result in child outcomes which would be approved of by a public health professional. But even if older women’s advice does contradict that of public health professionals, they are typically very influential in decisions around 13 maternal and child health, which suggests it is even more important to incorporate older women into public health interventions [30]. The positive results in the handful of studies which have incorporated grandmothers and older women in public health initiatives suggest this would be a fruitful avenue for improving maternal and child health [88–91], and mental health (Dixon Chibanda’s ‘Friendship Bench’ is perhaps the best known example of a successful intervention employing ‘grandmothers’ [92,93]). Ideologies around the family and ‘traditional’ gender roles feed into political ideologies which promote hierarchies of male dominance over women. Online fora have facilitated the spread of misogynistic movements, including Mens’ Rights Activist groups and Incels (“involuntary celibates”), which are collectively referred to as the ‘manosphere’. These movements use and misuse evolutionary psychology as their theoretical justification, and draw on supposedly biological arguments that women are ‘designed’ to bear and raise children while men are ‘designed’ to do pretty much everything else in society [94,95]. These movements have led to fatal terrorist attacks [96,97]. These ideologies not only present a terrorist threat, but also do not seem to benefit the men who adopt them, given such ideologies sometimes promote ‘men going their own way’ and removing themselves from (female) society [98]. The cooperative nature of our species suggests that such isolationism may not suit our evolved preferences [99]. At a less extreme level, the male breadwinner norm promotes ideals of male independence and isolation from others, since it assumes that men should have the ability to entirely provision a wife and children without support, which may feed into gender norms and socialisation which have been popularly referred to as ‘toxic masculinity’. These include emphasis on male dominance and self-reliance, and are considered to be detrimental to men, women and children [100]. Finally, despite the belief in some circles that intensive mothering, and lengthy, dependent childhoods, is optimal for children, the little research on the impact of intensive mothering does not find clear and conclusive evidence that such parenting has substantial positive effects on children [101]. Such childhoods may even fail to allow children to develop some of the skills they need to succeed in adult life [102]. Children and adolescents typically lack opportunities to develop parenting skills in Western societies, for example, as they are no longer involved in caring for younger children. Hrdy [1] also cautions us that, if we are a species adapted to a strategy of cooperative reproduction, then mothers raising children with little support from others, and keeping children dependent on mothers for lengthy periods, may hamper children’s abilities to develop the social, cognitive and emotional skills they need to succeed in adult society:14 “If empathy and understanding develop only under particular rearing conditions, and if an everincreasing proportion of the species fails to encounter those conditions but nevertheless survives to reproduce, it won’t matter how valuable the underpinnings for collaboration were in the past. Compassion and the quest for emotional connection will fade away as surely as sight in cave-dwelling fish”

People with more male descendants of a reproductive age had more conservative attitudes on gender-related issues and more conformity to traditional norms

Male Descendant Kin Promote Conservative Views on Gender Issues and Conformity to Traditional Norms. Nicholas Kerry et al. Evolutionary Human Sciences, May 28 2021. https://www.cambridge.org/core/journals/evolutionary-human-sciences/article/male-descendant-kin-promote-conservative-views-on-gender-issues-and-conformity-to-traditional-norms/1D5CB4B349E74C365828C2F25B8E1530

Abstract: Political and social attitudes have been shown to differ by sex in a way that tracks individual  self-interest. We propose that these attitudes also change strategically to serve the best  interests of either male or female kin. To test this hypothesis, we developed a measure of  gendered fitness interests (GFI)—an index which reflects the sex, relatedness, and residual  reproductive value of close kin. We predicted that people with male-biased GFI (i.e., people  with more male kin of a reproductive age) would have more conservative attitudes towards gender-related issues (e.g., gender roles, women‘s rights, abortion rights). An online study using an American sample (N = 560) found support for this hypothesis. Further analyses  revealed that this relationship was driven not only by people‘s own sex and reproductive  value but also by those of their descendant kin. Exploratory analyses also found a positive  association between male-biased GFI and a measure of conformity, as well as a smaller association between male-biased GFI and having voted Republican in the last election. Both  these associations were statistically mediated by gender-related conservatism. These findings  are consistent with the hypothesis that GFI influences socio-political attitudes.

Keywords: gendered fitness interests; inclusive fitness; motivated cognition; gender roles; political attitudes; conservatism

Vitamin S: Why Is Social Contact, Even With Strangers, So Important to Well-Being?

Vitamin S: Why Is Social Contact, Even With Strangers, So Important to Well-Being? Paul A. M. Van Lange, Simon Columbus. Current Directions in Psychological Science, May 27, 2021. https://doi.org/10.1177/09637214211002538

Abstract: Even before COVID-19, it was well known in psychological science that people’s well-being is strongly served by the quality of their close relationships. But is well-being also served by social contact with people who are known less well? In this article, we discuss three propositions that support the conclusion that the benefits of social contact also derive from interactions with acquaintances and even strangers. The propositions state that most interaction situations with strangers are benign (Proposition 1), that most strangers are benign (Proposition 2), and that most interactions with strangers enhance well-being (Proposition 3). These propositions are supported, first, by recent research designed to illuminate the primary features of interaction situations. This research shows that situations with strangers often represent low conflict of interest. Also, in interactions with strangers, most people exhibit high levels of low-cost cooperation (social mindfulness) and, if the need is urgent, high levels of high-cost helping. We close by sharing research examples showing that even very subtle interactions with strangers yield short-term happiness. Broader implications for COVID-19 and urbanization are discussed.

Keywords: human cooperation, weak ties, strangers, COVID-19, well-being

Proposition 3: Most Interactions With Strangers Enhance Well-Being

Most research on social interaction and happiness has focused on people connected by a relationships, such as close partners, friends, or colleagues. However, there are a few exceptions. First, scientists who have advanced the importance of weak ties have shown that people who know quite a few people beyond their close network tend be happier than those with smaller networks of acquaintances. Possible reasons are that weak ties may facilitate connection with other people, may help a person obtain good advice or useful information, or may inspire a person to attain certain goals. For example, classic research showed that a large majority of people find a job through acquaintances that they have met only infrequently, and a quarter of those acquaintances are people they seldom see (Granovetter, 1973). And because people generally are in a good mood (Diener et al., 2015), encountering kindness is more likely than encountering unkindness, a phenomenon that may partially explain why people tend to be socially mindful and helpful toward strangers (Van Doesum et al., 2021). Recent studies on relational mobility similarly have found that people living in cultures in which it is easier to meet strangers and form new relationships tend to have greater well-being (e.g., Yuki & Schug, 2020).

Setting aside material or future benefits, we propose that social interactions with strangers fulfill the need for social contact. This idea is consistent with theoretical analyses emphasizing needs such as affiliation, need to belong, or relatedness (e.g., Baumeister & Leary, 1995; Van Lange & Rusbult, 2012). Various lines of research support this claim. For example, the strength of weak ties is supported in research on social exclusion, which has shown that explicit or implicit signs of exclusion by strangers cause stress or discomfort in people. Being excluded in a ball-tossing game, even one that is virtual, causes strong aversion (e.g., Williams et al., 2000), and being ignored as a passenger (“to be looked at as though air”) causes feelings of disconnection (Wesselmann et al., 2012). Thus, at the very least, feeling appreciated by and connected to strangers matters.

The literature on weak ties has traditionally focused on the instrumental value of networks or the personal and societal benefits derived from interactions with members of other social groups. However, even fleeting interactions as such may have benefits. For example, in a recent study, students and community members were asked to count the number of times they greeted another person, regardless of the duration of the interaction. This study showed the strength of weak ties in that having more day-to-day interactions with acquaintances was associated with greater feelings of belonging and subjective well-being (Sandstrom & Dunn, 2014a).

Moreover, experimental studies in which people are instructed to greet, smile, or initiate a very brief conversation—a single encounter—have demonstrated that such approach behaviors boost people’s happiness. Such benefits have been found in interactions with a bus driver, with fellow commuters on a bus or train, with a person selling cappuccino at a coffee shop, or simply with a fellow participant waiting to take part in an experiment (e.g., Epley & Schroeder, 2014; Gunaydin et al., 2021). Moreover, the short-term boost in happiness occurs not only in the person initiating the conversation, but also in the person whose social contact was sought (Epley & Schroeder, 2014).

Our basic premise has been that interactions among strangers are benign, because the situations are benign and the strangers are often benign, and because the gratification of social contact fulfills basic psychological needs. Figure 2 provides a graphic summary of these propositions. From this perspective, one may ask why people “need’ interaction with strangers, and how such interactions might complement interactions with family and friends. We propose three reasons that illustrate the added value of interactions with strangers. First, close others are often part of a network of family members or friends. Although such connections are psychologically safe in numerous ways, there is always a risk that sensitive, private information shared with one or two close others may be spread in the larger social network. Strangers are far less likely to spread private information because they are unlikely to be part of one’s social network.

[Fig. 2. Summary of the three propositions: Situations with strangers are benign (left panel), strangers are benign (middle panel), and situations with strangers contribute to happiness and psychological well-being (right panel).]

Second, strangers are more likely than family or friends to be dissimilar in their background, attitudes, or opinions. This may yield gains in information (e.g., exposure to new perspectives) and amusement or excitement (e.g., exposure to unusual, novel events; Lewandowski & Aron, 2004). Also, when interactions with strangers elicit agreement in opinions, people may derive both enjoyment and confidence from having their opinions confirmed by others outside of their own network (e.g., Nickerson, 1998).

Third, and finally, compared with interactions with family or close friends, interactions with strangers may have the benefit of being more likely to provide opportunities, such as suggestions or advice regarding job opportunities, a chance to learn broader skills, or a starting point for beneficial exchange or extension of one’s social network (e.g., Granovetter, 1973).

Although the social benefits of interactions with strangers—Vitamin S—may be quite universal (e.g., Gunaydin et al., 2021), we acknowledge that individual differences matter. Some evidence suggests that extraverted individuals are more optimistic than introverted individuals about an interaction with strangers, even though the benefits after the actual experience do not differ much (Zelenski et al., 2013). The important implication of this finding is that some people might seek out new interactions with strangers to a lesser extent than others, and thus benefit less from opportunities for such interactions. This may be true not only for introverted people, but also for people who tend be less happy than average (e.g., Sandstrom & Dunn, 2014b). And last but not least, it is possible that there is an optimal level of Vitamin S for most people, that is, a level of social contact beyond which the benefits decline.