Childhood violence exposure, but not social deprivation, was associated with reduced adolescent resting-state neural network density

Association of Childhood Violence Exposure With Adolescent Neural Network Density. Leigh G. Goetschius et al. JAMA Netw Open. 2020;3(9):e2017850, September 23, 2020. doi:10.1001/jamanetworkopen.2020.17850

Key Points

Question  Are violence exposure and social deprivation associated with person-specific patterns (heterogeneity) of adolescent resting-state functional connectivity?

Findings  In this cohort study of 175 adolescents, childhood violence exposure, but not social deprivation, was associated with reduced adolescent resting-state density of the salience and default mode networks. A data-driven algorithm, blinded to childhood adversity, identified youth with heightened violence exposure based on resting-state connectivity patterns.

Meaning  Childhood violence exposure appears to be associated with adolescent functional connectivity heterogeneity, which may reflect person-specific neural plasticity and should be considered in neuroscience-based interventions.

Abstract

Importance  Adverse childhood experiences are a public health issue with negative sequelae that persist throughout life. Current theories suggest that adverse childhood experiences reflect underlying dimensions (eg, violence exposure and social deprivation) with distinct neural mechanisms; however, research findings have been inconsistent, likely owing to variability in how the environment interacts with the brain.

Objective  To examine whether dimensional exposure to childhood adversity is associated with person-specific patterns in adolescent resting-state functional connectivity (rsFC), defined as synchronized activity across brain regions when not engaged in a task.

Design, Setting, and Participants  A sparse network approach in a large sample with substantial representation of understudied, underserved African American youth was used to conduct an observational, population-based longitudinal cohort study. A total of 183 adolescents aged 15 to 17 years from Detroit, Michigan; Toledo, Ohio; and Chicago, Illinois, who participated in the Fragile Families and Child Wellbeing Study were eligible for inclusion. Environmental data from birth to adolescence were collected via telephone and in-person interviews, and neuroimaging data collected at a university lab. The study was conducted from February 1, 1998, to April 26, 2017, and data analysis was performed from January 3, 2019, to May 22, 2020.

Exposures  Composite variables representing violence exposure and social deprivation created from primary caregiver reports on children at ages 3, 5, and 9 years.

Main Outcomes and Measures  Resting-state functional connectivity person-specific network metrics (data-driven subgroup membership, density, and node degree) focused on connectivity among a priori regions of interest in 2 resting-state networks (salience network and default mode) assessed with functional magnetic resonance imaging.

Results  Of the 183 eligible adolescents, 175 individuals (98 girls [56%]) were included in the analysis; mean (SD) age was 15.88 (0.53) years and 127 participants (73%) were African American. Adolescents with high violence exposure were 3.06 times more likely (95% CI, 1.17-8.92) to be in a subgroup characterized by high heterogeneity (few shared connections) and low network density (sparsity). Childhood violence exposure, but not social deprivation, was associated with reduced rsFC density (β = −0.25; 95% CI, −0.41 to −0.05; P = .005), with fewer salience network connections (β = −0.26; 95% CI, −0.43 to −0.08; P = .005) and salience network-default mode connections (β = −0.20; 95% CI, −0.38 to −0.03; P = .02). Violence exposure was associated with node degree of right anterior insula (β = −0.29; 95% CI, −0.47 to −0.12; P = .001) and left inferior parietal lobule (β = −0.26; 95% CI, −0.44 to −0.09; P = .003).

Conclusions and Relevance  The findings of this study suggest that childhood violence exposure is associated with adolescent neural network sparsity. A community-detection algorithm, blinded to child adversity, grouped youth exposed to heightened violence based only on patterns of rsFC. The findings may have implications for understanding how dimensions of adverse childhood experiences impact individualized neural development.

Discussion

Results from a predominantly understudied and underserved sample with high rates of poverty suggest that childhood violence exposure, but not social deprivation, is associated with adolescent neural circuitry. Data-driven analyses identified a subset of adolescents with heterogeneous patterns of connectivity (ie, few shared and many individual connections) in 2 key neural networks associated with salience detection, attention, and social-cognitive processes (ie, the SN and DMN).^7,8 This subgroup of adolescents was exposed to more violence in childhood than the other subgroup, whose patterns of neural connectivity were relatively more homogeneous (ie, had many connections in common), suggesting that violence exposure may lead to more person-specific alterations in neural circuitry. Beyond subgroups, network density within the SN and between the SN and DMN was sparse for adolescents with high violence exposure, likely due to few connections involving the right insula and the left IPL. These factors could not be accounted for by social deprivation, in-scanner motion, race, sex, pubertal development, current life stress, or maternal marital status or educational level at the time of the participant’s birth.

Findings regarding the neural network subgroups are noteworthy because the community detection algorithm within GIMME detected rsFC patterns in the brain from exposures that occurred at least 6 years earlier. Moreover, high childhood violence exposure in the subgroup characterized by neural heterogeneity likely reflects the person-specific outcomes of early adversity on the brain and suggests that research on the developmental sequelae of adverse childhood experiences should consider individual differences in neural compensatory responses to stress.¹⁷ Although it is important to replicate these findings in other samples, S-GIMME has reliably classified subgroups in empirical data,^40,45 and there is evidence from simulations that modeling connections at the subgroup level, in addition to the group level, improves the validity and reliability of results.⁴⁰

Considering the sample as a whole, results also suggest that violence exposure is associated with blunted connectivity within the SN and between the SN and DMN. As expected, the observed reduced SN density in adolescents with heightened childhood violence exposure differs from typical developmental patterns that show stronger rsFC within SN nodes and increased density of connections with hub regions, such as the anterior insula, as the brain matures.^8,16 It is difficult, however, to align the present findings with previous work that reported increased SN rsFC in trauma-exposed youth^9,10 because those samples were small, used different metrics of connectivity, and had different sample compositions. Moreover, the present sample was likely experiencing chronic adversity, and research from animal models of chronic stress proposes that, over time, the body’s stress response (eg, hypothalamic pituitary adrenal axis reactivity) becomes blunted or habituated to typical stressors.⁴⁷ Previous research on hypothalamic pituitary adrenal axis reactivity in this sample revealed a blunted cortisol response in adolescents with heightened childhood violence exposure,²⁸ and work in other high-risk samples showed blunted activation of the amygdala, an SN node, to threatening stimuli.^48,49 The present study expands this notion to the function of threat detection neural circuits, and future research should examine whether this is compensatory or even adaptive.

Beyond density, childhood violence exposure was associated with reduced node degree of the right anterior insula and left IPL. These results are consistent with the extant literature because the right anterior insula in the SN facilitates shifting between the DMN and central executive network,⁵⁰ which contributes to higher-level executive function.⁸ Moreover, early life stress has been linked to insular connectivity within the SN,⁹ DMN (specifically, the left IPL, which plays a role in working memory⁵¹), and other neural ROIs.⁵² These results also show differences in the way that the anterior insula is integrated within and between neural networks in youth exposed to violence in their homes and neighborhoods using longitudinal data from a population-based sample.

This study represents a person-specific approach to the neuroscientific investigation of the sequelae of early adversity. Past research on early adversity and rsFC assumed that the same connectivity patterns characterize all, or a majority of participants, but if this assumption is violated (as is likely the case in studies of diverse populations and biopsychosocial phenomena), then results may not accurately describe any individual.^18,53 The presence of group- and subgroup-level connections in the present study suggests that there is some consistency in the connections within and between the SN and DMN, aligning with an assumption of homogeneity that is prevalent in rsFC research, but the large number of individual-level connections, especially in adolescents with high levels of early violence exposure, show that there was also notable heterogeneity that required person-specific analyses to accurately reflect rsFC, encouraging future research using person-specific modeling approaches.

All significant findings concerned violence exposure, and there were no detected associations between social deprivation and rsFC. This set of results could indicate that social deprivation has a less salient influence on patterns of spontaneous neural fluctuations. Some studies have identified links between social deprivation and functional connectivity, but they concerned extreme, nonnormative deprivation (eg, previous institutionalization).^21,54 This deprivation may be qualitatively different from deprivation operationalized in the present study, and may operate through different mechanisms. In addition, because a hypothesis-driven approach to node selection was taken in this study, it is possible that deprivation is associated with rsFC of SN or DMN nodes not measured here, with other networks (eg, central executive), or in different populations (eg, with extreme or heightened variability of deprivation). It is also tenable that there are other dimensions of adversity that would have differential associations with rsFC (eg, those linked to emotionality), which future research should explore. Nonetheless, these findings present evidence for dimensional frameworks of adversity^5,55 because there were distinct neural correlates for violence exposure.

Limitations

This study had limitations. Based on the demographic characteristics of the sample (eg, 73% African American, born in Midwestern cities), it is not clear whether findings will generalize beyond low-income, urban, African American youth; nonetheless, the present work is important because these populations are often underrepresented in neuroimaging research and underserved by the medical community.¹² Resting-state functional MRI was collected on only a single occasion in adolescence; thus, it is unclear whether connectivity patterns reflect stable or changing neural features. In addition, it is not possible to know the direction of association (eg, whether neural differences predate exposure to adversity). Violence exposure and social deprivation composites were derived from parent reports. Exposures between the FFCWS collection waves at ages 9 and 15 years could not be accounted for in this study. Owing to changes in the FFCWS questionnaire at year 15, current adversity could not be controlled using the composite scores created for earlier ages.⁵ To compensate, a life stress scale was used as a covariate; however, that confounding variable did not impact associations. The ecologic pattern of poverty-related adversity is complex; thus, there are unmeasured variables that may explain these associations or contribute to cascades of risk (eg, parental psychopathologic factors).

Genetic differences in religiousness and extra-familial environmental influences increased with age, whereas shared environmental influences within families declined – in particular in the first half of life

 A meta-analytic review of nature and nurture in religiousness across the lifespan. Christian Kandler. Current Opinion in Psychology, September 23 2020. https://doi.org/10.1016/j.copsyc.2020.09.011

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308988159901003786

Abstract: Behavior genetic research yielded that affiliation to a specific religion is primarily environmental, whereas religious beliefs and practices irrespective of a specific religion have been found to be heritable to some degree. This review synthesizes the literature and provides a meta-analytic overview on all identified behavior genetic studies on religiousness since 1999. This analysis allows new insight on the nature–nurture interplay in the development of religiousness: Genetic differences in religiousness and extra-familial environmental influences increased with age, whereas shared environmental influences within families declined – in particular in the first half of life. This age trend is in line with the interpretation of an increasing importance of active gene–environment transactions and accumulating extra-familial environmental factors across the lifespan.

Prevalent emotion‐theories of psychopathy appear to operate with the assumption that psychopaths have no emotions, leading to the hypothesis that psychopaths are (almost) completely unable to make moral judgments

Are psychopaths moral‐psychologically impaired? Reassessing emotion‐theoretical explanations. Rasmus Rosenberg Larsen. Mind & Language, September 22 2020. https://doi.org/10.1111/mila.12317

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308793107358658563

Abstract: Psychopathy has been theorized as a disorder of emotion, which impairs moral judgments. However, these theories are increasingly being abandoned as empirical studies show that psychopaths seem to make proper moral judgments. In this contribution, these findings are reassessed, and it is argued that prevalent emotion‐theories of psychopathy appear to operate with the unjustified assumption that psychopaths have no emotions, which leads to the hypothesis that psychopaths are completely unable to make moral judgments. An alternative and novel explanation is proposed, theorizing psychopathy as a degree‐specific emotional deficiency, which causes degree‐specific differences in moral judgments.

No evidence that modern types of wheat have lower quality for human nutrition and health, with the exception of decreased levels of some minerals (including iron, zinc and magnesium)

Do modern types of wheat have lower quality for human health? P. R. Shewry  K. L. Hassall  H. Grausgruber  A. A. M Andersson  A.‐M. Lampi  V. Piironen  M. Rakszegi  J. L. Ward  A. Lovegrove. Nutrition Bulletin, September 22 2020. https://doi.org/10.1111/nbu.12461

Abstract: Wheat is the major staple food in Western Europe and an important source of energy, protein, dietary fibre, minerals, B vitamins and phytochemicals. Plant breeders have been immensely successful in increasing yields to feed the growing global population. However, concerns have been expressed that the focus on increasing yield and processing quality has resulted in reduced contents of components that contribute to human health and increases in adverse reactions. We review the evidence for this, based largely on studies in our own laboratories of sets of wheats bred and grown between the 18th century and modern times. With the exception of decreased contents of mineral micronutrients, there is no clear evidence that intensive breeding has resulted in decreases in beneficial components or increases in proteins which trigger adverse responses. In fact, a recent study of historic and modern wheats from the UK showed increases in the contents of dietary fibre components and a decreased content of asparagine in white flour, indicating increased benefits for health.

Discussion

It is clear from the studies discussed above that intensive wheat breeding has resulted in increased accumulation of starch, which is generally associated with a decrease in the concentration of protein. Analysis of the Austrian Heritage lines also indicates that there have not been increases in proteins known to trigger adverse reactions. Other effects of breeding on grain composition are less clear, and the studies discussed in detail here demonstrate the challenges.

One major challenge is that grain composition is strongly affected by the environment (Shewry et al. 2010). Hence, it is essential to compare material grown in replicated multi‐environment field trials. Furthermore, the varieties compared should be adapted to the area of growth, to avoid the effects of environmental stress. The HEALTHGRAIN study clearly did not fulfil these criteria, and it is not surprising that few correlations were observed, and, with the exception of starch and protein, these were marginal in significance (accounting for between 2% and 5% of the variation observed in the analyses). Nevertheless, the analyses are of interest in that they show no major changes in composition.

By contrast, the UK Heritage Wheat samples were from replicated multi‐site trials with an emphasis on flour composition. Statistical analyses of these samples showed positive correlations of release date with the contents of arabinoxylan fibre (accounting for 21% of the total variation), total sugars (41%) and betaine (19%), and negative correlations with total amino acids (15%) and individual amino acids including asparagine (Lovegrove et al. 2020). These changes have clear implications for human health.

Wheat is the most important single source of dietary fibre in many diets, including the UK and Western Europe, and the increased content of arabinoxylan (the major fibre component) in white flour is certainly desirable. The decreased concentration of asparagine in modern wheats is also desirable as it reduces the potential for the formation of acrylamide during processing.

By contrast, the increases in fermentable monosaccharides, disaccharides and oligosaccharides (sucrose, mannitol, fructans) may be of concern to consumers suffering from irritable bowel syndrome (IBS), as these form part of the FODMAP fraction (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) that exacerbate IBS symptoms (Gibson & Shepherd 2010). However, wheat is already recognised as a major source of FODMAPs in the diet (Biesiekierski et al. 2011; Whelan et al. 2011) and excluded by many IBS patients.

To conclude, the analyses discussed provide no evidence that modern types of wheat have lower quality for human nutrition and health, with the exception of decreased levels of some minerals (including iron, zinc and magnesium) which are discussed elsewhere. In fact, there is evidence that they may be superior in some respects, particularly in fibre content of white flour. However, the analyses also show the challenges facing researchers and the need for more datasets from well‐designed field trials.

Does Sex Really Sell? Paradoxical Effects of Sexualization in Advertising on Product Attractiveness and Purchase Intentions

Does Sex Really Sell? Paradoxical Effects of Sexualization in Advertising on Product Attractiveness and Purchase Intentions. Sarah Gramazio, Mara Cadinu, Francesca Guizzo & Andrea Carnaghi. Sex Roles (2020), September 23 2020. https://link.springer.com/article/10.1007/s11199-020-01190-6

Abstract: To test the “sex sells” assumption, we examined how Italian men and women react to sexualized advertising. Women showed lower product attractiveness and purchase intentions toward products presented with sexualized female models than with neutral ads, whereas men were unaffected by ads’ sexualization (Study 1, n = 251). Study 2 (n = 197) replicated the overall results. Study 3 (n = 198) tested hostile sexism as a moderator as well as negative emotions as a mediator of consumers’ responses. Especially men with higher hostile sexism showed more purchase intentions after viewing female sexualized ads than neutral ads. Moreover, women’s lower consumer responses toward sexualized female ads were due to higher negative emotions. Study 4 (n = 207) included ads with both female and male models, replicating responses to female sexualization and showing that both women and men had lower product attractiveness and purchase intentions toward male sexualized ads than neutral ads. Replicating and extending Study 3’s results, women’s negative emotions was the mediator. The present study has practical implications for marketers because it suggests that “sex does not sell.” In addition, considering both the psychological damage and practical inefficacy of sexualized ads, our findings have important implications for public policy.

General Discussion

The present research showed a series of important results. First, across the four studies we have confirmed Hypothesis 1b, namely that women were less attracted toward products and had lower purchase intentions when they were presented with sexualized female models than with neutral ads. Second, and disconfirming Hypothesis 1a, men, contrary to women, were largely unaffected by the level of female sexualization of the ads. These results are further supported by the meta-analysis, which provides a reliable and trustworthy pattern of cumulative evidence.

In addition, contrary to Hypothesis 2, in Study 2 participants’ attitudes that view women as sexual objects and men as sex-driven were not related to their reactions toward the female model ads. Moreover, both in Study 3 and Study 4 and in line with Hypothesis 3a, women reported higher negative emotions after exposure to female sexualized than neutral ads. However, partially disconfirming Prediction 3b, women’s positive emotions varied across conditions in Study 4 but not in Study 3. In addition, in line with the lack of effects on product attractiveness and purchase intentions, men’s emotions were never affected by condition.

Most importantly, consistent with Hypothesis 4, in Study 3 women’s negative emotions toward sexualized female (vs. neutral) ads were found to be one mechanism underlying their decrement on product attractiveness and purchase intentions. In addition, in line with Hypothesis 5b, Study 3 also demonstrated hostile sexism as one individual difference that moderated purchase intentions: Higher hostile sexism in men was associated with higher purchase intentions after viewing sexualized female ads than neutral ads. Moreover, hostile sexism predicted higher purchase intentions among women in the control condition.

Moreover, in line with Hypothesis 6, in Study 4 both men and women expressed lower product attractiveness and purchase intentions toward sexualized male model ads than neutral ads. In addition, partially confirming Hypothesis 7b, women showed higher negative emotions toward male sexualized ads compared to neutral ads, whereas men’s emotions did not vary. Importantly, in Study 4 we extended the mediation analysis to male model ads by showing that women’s negative emotions were responsible for the decrement on product attractiveness and purchase intentions toward both female and male models sexualized (vs. neutral) ads.

Overall, our findings on product attractiveness and purchase intentions substantially advance Wirtz et al.’s (2018) results by showing that female sexualization in advertising has a negative effect on women’s responses and has a null effect on men’s responses and that the use of male sexualization is counterproductive both for women and men. Concerning male model ads, this pattern of results contributes to Wirtz et al.’s analyses because it clearly demonstrates that not only men, but also women, dislike male sexualization in advertisement, in contrast with Jones et al.’s (1998) claims. Concerning female model ads, our pattern of results is in contrast with Wirtz et al.’s conclusions regarding men’s higher attractiveness toward sexualized female ads and women’s lack of effect on purchase intentions. One possibility to explain this discrepancy is the fact that Wirtz et al.’s meta-analysis includes studies starting from the early 1970s and the advertising context nowadays might be different. Indeed, in the last decade, the femvertising movement for body-positive advertising has emerged and new ad campaigns using empowerment messages to women were created (Castillo 2014; Teng et al. 2020). Therefore, in the last decade people may have developed an appreciation for a variety of female and male model ads that goes beyond sexualization, a possibility that would help explain our participants’ mostly negative reactions toward sexualized ads.

Another important finding of the present study is that exposure to sexualized ads significantly impacts women’s emotions. These findings enrich an under-investigated area of research. Indeed, although some studies indicated that consumers who purchase new products are more likely to form preferences (favorable or unfavorable) based on affective evaluations (Muehling and McCann 1993; Reichert 2002), research that analyzes advertisement-related emotions within the context of sexualization is scarce. Therefore, a significant theoretical contribution of the present study is our moderated mediation analyses, which suggest that negative emotions can work as one mechanism that regulates women’s reactions. Overall, sexualized images work against women’s product attractiveness and purchase intentions because they elicit negative emotions.

Moreover, the present study deepens our understanding of the moderating role of individual differences in gender attitudes on the relation between female ad sexualization and purchase intentions: Especially men with higher hostile sexism showed more purchase intentions after viewing sexualized than neutral ads. This finding nicely parallels results by Zawisza et al. (2018) who showed a positive association between hostile sexism and purchase intentions toward stereotypically feminine ads. In addition, our results suggest that the endorsement of hostile sexism by men may favor the validation of sexualized female models proposed by media. Given that the exposure to female sexualized images increases hostile sexism (Fox and Potocki 2016; Rollero 2013), our results complement this evidence and suggest a vicious circle between female sexualization and hostile sexism. Future research should further investigate this possibility and test whether it is specific to hostile sexism or it may also extend to benevolent sexism, a construct that was not measured in the present study. An additional unexpected result was that the higher women’s hostile sexism, the higher their purchase intentions in the control condition. This result suggests a general relation between women’s level of hostile sexism and consumerism, a possibility that should be further investigated in future research.

Limitations and Future Research Directions

The present research presents some limitations. In line with previous literature we have tested the role of the gender-relevance of the products on product attractiveness and purchase intentions and found no significant effects. However, the products chosen were not varied in a systematic way with respect to other characteristics. For example, some products were gendered in a way that may make them less appealing to female consumers (e.g., men’s shoes), thus creating a potential confound leading to the decrease in women’s preferences. However, the gender of our participants did not affect the results in the control condition, which helps exclude the possibility of such a confound. Nevertheless, it would still be important for future studies to systematically vary the products’ gender target. Also related to this point, future research may assess participants’ relationship status, a variable that we did not assess and that may further modulate participants’ responses because some products may be interesting to buy for one’s partner. In addition, the economic value of the products (luxury vs. inexpensive) was not systematically varied; future research may be conducted to ascertain whether this feature may also modulate consumers’ responses toward sexualized versus neutral ads.

In all four studies, we compared sexualized ads including (fe)male models in revealing clothing to neutral ads including the same product as in the sexualized condition, but devoid of the model. To have a further control condition, we suggest future studies also have the same (fe)male models but portrayed in non-sexualized ways. More generally, we think that Study 4’s results on the effects of male sexualized models are promising especially because they demonstrate that the mediating role of women’s negative emotions nicely parallel results obtained toward female sexualized models. However, our study did not provide any information on the reasons why men responded unfavorably to sexualized male model ads. One speculation is that male ad sexualization confronts men with their explicit or implicit homophobia. To explore this possibility, future research may further investigate men’s reactions toward male sexualized ads by also assessing homophobia and masculinity norms.

Finally, another future direction of the present study is to diversify the type of models included in the ads. The present study was conducted in Italy and all models were White and reflected the sexualized thin ideal for women and the muscular ideal for men. Therefore, we suggest more diversity in future studies.

Practice Implications

The present study presents several practical implications. Concerning marketing, our results are at odds with current sexualizing marketing strategies, which are based on the assumption that “sex sells.” Indeed, our findings suggest that, at the marketing level, the use of female sexualization in advertising is counterproductive for women and useless for men as consumers and that the use of male sexualization is counterproductive both for women and men. Put differently, our findings show that “sex does not sell,” a result that questions sexualization as a useful marketing strategy.

Concerning ethical implications, the present findings complement a large amount of research based on objectification theory that has shown detrimental effects of exposure to media sexualization on women’s and men’s well-being (Agliata and Tantleff-Dunn 2004; Leit et al. 2002; Lorenzen et al. 2004; Ward 2016). Therefore, considering the psychological damage and the practical inefficacy of sexualized ads, we argue that sexualization in advertising should be addressed in public policy discourse. This issue is particularly relevant with respect to sexualized advertisement aimed at children (Pacilli et al. 2016), which would require even stricter regulations. Also relevant to public policy, media literacy programs may be employed to buffer the negative effects of media sexualization (see Guizzo and Cadinu 2020; Tylka and Augustus-Horvath 2011).

Drawing on dual-process theory, we suggest that the benefits that arise from combining several quantitative individual judgments will be heightened when the judgments are based on different cognitive processes

Enhancing the Wisdom of the Crowd With Cognitive-Process Diversity: The Benefits of Aggregating Intuitive and Analytical Judgments. Steffen Keck, Wenjie Tang. Psychological Science, September 22, 2020. https://doi.org/10.1177/0956797620941840

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308645051766116352

Abstract: Drawing on dual-process theory, we suggest that the benefits that arise from combining several quantitative individual judgments will be heightened when these judgments are based on different cognitive processes. We tested this hypothesis in three experimental studies in which participants provided estimates for the dates of different historical events (Study 1, N = 152), made probabilistic forecasts for the outcomes of soccer games (Study 2, N = 98), and estimated the weight of individuals on the basis of a photograph (Study 3, N = 3,695). For each of these tasks, participants were prompted to make judgments relying on an analytical process, on their intuition, or (in a control condition) on no specific instructions. Across all three studies, our results show that an aggregation of intuitive and analytical judgments provides more accurate estimates than any other aggregation procedure and that this advantage increases with the number of aggregated judgments.

Keywords: decision making, judgment, cognitive processes, wisdom of the crowd, judgment aggregation, group judgments, dual-process theory, open data

General Discussion

The results of three experimental studies showed that forming crowds with a high level of cognitive-process diversity—by aggregating a combination of intuitive and analytical individual judgments—improved the quality of crowd wisdom, compared with crowds formed by an aggregation of only analytical judgments, only intuitive judgments, or judgments made in a control condition without specific manipulation of judges’ cognitive processes. Moreover, we found that whereas the benefits of cognitive-process diversity generally held for both smaller and larger crowds, the magnitude of these benefits increased with crowd size and eventually approached its maximum as crowds became very large. Providing supporting evidence for the suggestion that the benefits of cognitive-process diversity are driven by higher levels of judgment-error independence, the results of Studies 1 and 2 revealed a lower average correlation in signed errors between judges employing an intuitive cognitive process and those employing an analytical cognitive process, compared with judges relying on the same cognitive process or judges in the control condition.

One particularly interesting finding of Study 3 is that analytical-intuitive crowds still outperformed purely analytical crowds even though individual analytical judgments were more accurate than individual intuitive judgments—implying that in this specific context the benefits of adding more uncorrelated judgments outweighed the detrimental effects of adding less accurate judgments. It is, however, important to note that there are likely a number of domains (e.g., tasks that require the application of formal logic) in which intuitive judgments would be much less accurate than analytical ones and hence adding highly inaccurate though less correlated judgments to a crowd is likely not beneficial (e.g., Mannes et al., 2014).

Previous research has suggested ways to improve judgment aggregation, such as by selecting better performing individuals (e.g., Budescu & Chen, 2014; Mannes et al., 2014) or by refining the aggregation procedure (e.g., Jose & Winkler, 2008; Palley & Soll, 2019). By contrast, our approach focused on increasing independence between individual judgment errors by manipulating the cognitive process employed by individual judges to form their judgments. It thus also complements recent work by de Oliveira and Nisbett (2018), who investigated the possibility of improving crowd wisdom by amplifying the demographic diversity of crowds and found that this approach was largely ineffective. A likely explanation for this difference in results is that we directly manipulated the cognitive process by which judgments were being made, whereas demographic differences frequently might not be associated with differences in individual cognition.

One limitation of our work is that we manipulated judgments to either be predominantly intuitive or predominantly analytical. However, in practice, judgments and decisions might frequently be based on a process in the middle of a continuum with analytical and intuitive processes at the boundaries (e.g., Hammond, 1996). Thus, an interesting direction for future research would be to compare our approach with one in which a crowd is formed by aggregating judgments that are each based on a mixture of analytical and intuitive processes. A related important limitation of our results is that we did not provide direct insights into differences in participants’ exact cognitive processes, such as the use of different judgment rules or reliance on different pieces of information (e.g., Herzog & von Helversen, 2018; Hoffmann et al., 2013). Such differences might explain the higher independence between analytical and intuitive judgments observed in our studies.

A final interesting avenue for future research would be to explore whether our approach toward improving the wisdom of crowds might also help to increase the effectiveness of combining judgments that are made by the same individual (e.g., Herzog & Hertwig, 2009, 2014; Vul & Pashler, 2008).

General Discussion

The results of three experimental studies showed that forming crowds with a high level of cognitive-process diversity—by aggregating a combination of intuitive and analytical individual judgments—improved the quality of crowd wisdom, compared with crowds formed by an aggregation of only analytical judgments, only intuitive judgments, or judgments made in a control condition without specific manipulation of judges’ cognitive processes. Moreover, we found that whereas the benefits of cognitive-process diversity generally held for both smaller and larger crowds, the magnitude of these benefits increased with crowd size and eventually approached its maximum as crowds became very large. Providing supporting evidence for the suggestion that the benefits of cognitive-process diversity are driven by higher levels of judgment-error independence, the results of Studies 1 and 2 revealed a lower average correlation in signed errors between judges employing an intuitive cognitive process and those employing an analytical cognitive process, compared with judges relying on the same cognitive process or judges in the control condition.

One particularly interesting finding of Study 3 is that analytical-intuitive crowds still outperformed purely analytical crowds even though individual analytical judgments were more accurate than individual intuitive judgments—implying that in this specific context the benefits of adding more uncorrelated judgments outweighed the detrimental effects of adding less accurate judgments. It is, however, important to note that there are likely a number of domains (e.g., tasks that require the application of formal logic) in which intuitive judgments would be much less accurate than analytical ones and hence adding highly inaccurate though less correlated judgments to a crowd is likely not beneficial (e.g., Mannes et al., 2014).

Previous research has suggested ways to improve judgment aggregation, such as by selecting better performing individuals (e.g., Budescu & Chen, 2014; Mannes et al., 2014) or by refining the aggregation procedure (e.g., Jose & Winkler, 2008; Palley & Soll, 2019). By contrast, our approach focused on increasing independence between individual judgment errors by manipulating the cognitive process employed by individual judges to form their judgments. It thus also complements recent work by de Oliveira and Nisbett (2018), who investigated the possibility of improving crowd wisdom by amplifying the demographic diversity of crowds and found that this approach was largely ineffective. A likely explanation for this difference in results is that we directly manipulated the cognitive process by which judgments were being made, whereas demographic differences frequently might not be associated with differences in individual cognition.

One limitation of our work is that we manipulated judgments to either be predominantly intuitive or predominantly analytical. However, in practice, judgments and decisions might frequently be based on a process in the middle of a continuum with analytical and intuitive processes at the boundaries (e.g., Hammond, 1996). Thus, an interesting direction for future research would be to compare our approach with one in which a crowd is formed by aggregating judgments that are each based on a mixture of analytical and intuitive processes. A related important limitation of our results is that we did not provide direct insights into differences in participants’ exact cognitive processes, such as the use of different judgment rules or reliance on different pieces of information (e.g., Herzog & von Helversen, 2018; Hoffmann et al., 2013). Such differences might explain the higher independence between analytical and intuitive judgments observed in our studies.

A final interesting avenue for future research would be to explore whether our approach toward improving the wisdom of crowds might also help to increase the effectiveness of combining judgments that are made by the same individual (e.g., Herzog & Hertwig, 2009, 2014; Vul & Pashler, 2008).

Just kidding: the evolutionary roots of playful teasing

Just kidding: the evolutionary roots of playful teasing. Johanna Eckert, Sasha L. Winkler and Erica A. Cartmill. Biology Letters, September 23 2020, Volume 16, Issue 9. https://doi.org/10.1098/rsbl.2020.0370

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308635232736862209

Abstract: Accounts of teasing have a long history in psychological and sociological research, yet teasing itself is vastly underdeveloped as a topic of study. As a phenomenon that moves along the border between aggression and play, teasing presents an opportunity to investigate key foundations of social and mental life. Developmental studies suggest that preverbal human infants already playfully tease their parents by performing ‘the unexpected,’ apparently deliberately violating the recipient's expectations to create a shared humorous experience. Teasing behaviour may be phylogenetically old and perhaps an evolutionary precursor to joking. In this review, we present preliminary evidence suggesting that non-human primates also exhibit playful teasing. In particular, we argue that great apes display three types of playful teasing described in preverbal human infants: teasing with offer and withdrawal, provocative non-compliance and disrupting others' activities. We highlight the potential of this behaviour to provide a window into complex socio-cognitive processes such as attribution of others’ expectations and, finally, we propose directions for future research and call for systematic studies of teasing behaviour in non-human primates.

4. Cognitive implications of playful teasing

Some authors have proposed that playful teasing in human infants provides a window into their rich early ‘theory of mind’ abilities, as well as into proto-forms of humour (e.g. [18,21,23–27,64]). If apes (or other animals) engage in similar forms of playful teasing, do they also have some understanding of the expectations of others? Is it possible that great apes, like human infants, deliberately play with these expectations for the sake of amusement?

The study of ‘theory of mind,’ i.e. the ability to ascribe mental states to others, has been of central interest in comparative psychology for several decades (see [65–67] for reviews). There is ample evidence showing that great apes (i) ascribe intentions and goals to others (e.g. [66,68–70]), (ii) are aware of attentional states of others (i.e. what they can see or hear; e.g. [71–74]) and (iii) make use of this knowledge in both competitive and cooperative contexts (e.g. [75]). Crucially, recent research demonstrated that apes are also capable of ‘mind-reading’ abilities that require a simultaneous representation of two conflicting views of the world: one's own (correct) perspective and the (incorrect) perspective of another individual [76]. Hence, great apes are not only sensitive to what other individuals intend to do and what they know, but they also have some understanding of others' beliefs, even when these beliefs conflict with reality (also see [77–79] for similar findings on false belief attribution in young children).

Playful teasing events, such as the offer-withdrawal, presumably involve rich inferences on both the side of the teaser and the side of the recipient. A typical offer-withdrawal event starts with the teaser making an ‘offer’ gesture, inviting the recipient to reach for an extended object or limb. All species of great apes produce offer gestures, e.g. in the context of food sharing [80] or grooming [81]. Hence, it is reasonable to assume that both parties are aware of the typical use of this gesture to draw attention to a body part of the signaller or to transfer something to the recipient. Also, there is evidence that apes produce this gesture type intentionally to pursue a particular goal [54,82]. Gestures are typically deemed to be intentional if they are (i) motorically ineffective, (ii) directed towards another individual, (iii) goal-directed and (iv) demonstrate flexibility in their usage. Goal-directedness is often shown through the use of response waiting or through persistent attempts to communicate. Teasing events may take different forms than gestures, but if they are fundamentally communicative in nature and are aimed at eliciting a particular response from the target, they will likely demonstrate the same markers of intentionality as seen in ape gesturing.

These markers seemed to be present in the videos of orangutan offer-and-withdrawal events (collected for [55]). The teaser usually seemed to await a particular response from the recipient after offering the object or limb (anticipating a reaching-out-to-take action). If this response was not given, the teaser slightly modified or intensified the offer gesture. In one case, an orangutan offered another a stick by holding it within their reach. When the recipient did not reach for it (because it had previously made an unsuccessful attempt to obtain the stick), the teaser started waving the object in front of the recipient's face. Only once the recipient reached for the stick, did the teaser withdraw the offer (figure 1d–f). While more systematic observations of object-teasing are needed, this behavioural sequence (waiting for a response and modifying the signal when the response did not occur) suggests that apes produced this offer gesture intentionally to elicit the other's attempt to retrieve the item, a response which they then thwarted by withdrawing the offer. It is undeniably difficult to attribute specific goals to teasers (or gesturers) without relying solely on the intuition of the observer. However, careful examination of the satisfying conditions under which the teaser (or gesturer) stops acting can be used to test the observer's attributions of the goal. This has been a very successful method for analysing the meanings of ape gestures (e.g. [55]). Once the offer is withdrawn, the recipient needs to interpret the intention of the teaser as being affiliative (or neutral) rather than aggressive. Primates typically respond with anger when humans retract offers (e.g. [83]). In order to maintain a positive interaction surrounding the teasing behaviour, recipients cannot rely on the teasing behaviour alone but must take into account their relationship with the teaser, the teaser's affective state and other contextual information. These cognitive inferences are even more critical in the absence of overt play signals (e.g. play-face). Because teasing can be a highly ambiguous behaviour, responding to teasing as play—especially participating in teasing ‘games’ like repeated offers with withdrawal—requires careful assessment of social cues and relationships as well as inferences about the other's motivation in a given interaction (also see [58] for a valuable discussion on how different animal species manage and overcome the ambiguity of actions during play fighting).

5. Humorous play with others' minds?

An intriguing question is whether ape teasers not only expect a specific action response from the recipient but whether they also attribute expectations to their recipient (e.g. the expectation that the teaser will transfer an object). As mentioned above, (false) belief attribution has only been demonstrated recently in apes in a single study employing implicit measures [76]. The occurrence of teasing with offer and withdrawal could provide a hint that apes not only have an implicit understanding of others’ beliefs but that they may even actively create false beliefs by intentionally evoking expectations in the other, before disrupting them.

The deliberate creation of false expectations has previously been discussed in the context of a structurally similar but functionally different behaviour displayed by non-human primates: tactical deception (see [84,85] for reviews). Tactical deception describes ‘acts from the normal repertoire of the agent, deployed such that another individual is likely to misinterpret what the acts signify, to the advantage of the agent’ [81]. There is evidence that great apes use tactical deception in naturally occurring situations [85] and experimental contexts (e.g. [86,87]). Hence, apes do occasionally use false communicative signals to influence the behaviour of others.

One idiosyncrasy of playful teasing is that, in contrast with tactical deception, no immediate fitness benefits are apparent. One possible explanation is that playful teasing constitutes a safe domain within which to explore social rules and boundaries (see [21,23–25]). Research on play fighting in apes suggests that individuals can test social rules in play that they might not be able to explore outside the play context (e.g. [88]). Another possibility is that the teasing behaviour evokes a positive affective state in the teaser and perhaps also in the recipient. For human infants, a suggested proximate function of playful teasing is to create a shared humorous experience between teaser and recipient (e.g. [21]), which may strengthen their social bond (but see [27] for an alternative proposition). Social bonds are critically important for fitness in non-human primates [89,90]. Is it, thus, possible that apes also experience positive emotions such as amusement when playfully teasing others and that sharing such moments enhances bonding between individuals?

This question is related to a more general discussion about whether great apes, or any non-human animals, appreciate humour. One widely used definition of humour states that incongruity with respect to reality is the source of humour [28,29]. This incongruity must be in the form of a benign (i.e. harmless) expectation violation; otherwise, it will elicit negative emotions instead of amusement [91]. Creating this incongruity involves a cognitive understanding of action norms and how those can be violated [26]. Great apes have previously demonstrated such understanding in the context of imitation recognition [92,93]. Moreover, apes' playful teasing fulfils the criteria of the benign expectation violation theory [91]. Hence, technically, playful teasing might be viewed as a humorous act. The question is whether apes, like humans, also appreciate this humorous component and experience a positive emotional state during teasing interactions.

In humans, studying humour and its effects on affective states is eased by the fact that, from early infancy onwards, amusement is often (but not always) accompanied by a distinct emotional expression: laughter [94,95]. Importantly, great apes also emit laughter-like vocalizations (though mostly during dynamic social activities like wrestling, tickling and chasing games [96–98]), suggesting that apes may experience joy during social interactions. Chimpanzees not only laugh spontaneously but also after hearing the laughter of others [99]. Chimpanzee play sessions involving laughter contagion last longer than play involving only spontaneous laughter (or no laughter at all), suggesting that, like in humans, shared laughter may facilitate positive social interaction and enhance bonding (also see [100,101] for evidence of contagious play vocalizations in rats and kea parrots).

Studies documenting offer-withdrawal, provocative non-compliance or disruption of other's activities in apes reported that these behaviours occurred in playful contexts and, thus, likely involved a positive emotional state. However, most studies did not report on any affective signals, such as play-face or laughter (but see [48,50]). Hence, while teasing constitutes an excellent place to look for potential antecedents of joking behaviour and humour in great apes, future research will need to pay close attention to markers of positive affect during these activities. Finding evidence that both teaser and recipient exhibit positive affective states would strengthen the hypothesis that non-human animals are capable of creating and appreciating humorous experiences, and that they, like human infants, use mild expectation-violations to strengthen their bonds.