Helmholtz Versus Haute Couture: How Horizontal Stripes and Dark Clothes Make You Look Thinner

Helmholtz Versus Haute Couture: How Horizontal Stripes and Dark Clothes Make You Look Thinner. Antonis Koutsoumpis, Elias Economou, Erik van der Burg. Perception, August 16, 2021. https://doi.org/10.1177/03010066211038158

Abstract: In Helmholtz’s illusion, a square with horizontal stripes appears taller than an identical square with vertical stripes. This effect has also been observed in experiments with human stimuli, where a human figure wearing a dress with horizontal stripes appears thinner than a drawing clad in vertical stripes. These findings do not agree with the common belief that clothes with horizontal stripes make someone appear wider, neither do they disentangle whether the horizontal or vertical stripes account for the thinning effect. In the present study, we focused on the effect of horizontal stripes in clothes comparing horizontal stripes against no-stripes (not against vertical; Experiments 1 and 2), using photos of a real-life female model, and controlling for the average luminance of the stripes (Experiment 2). Results showed that horizontal stripes and lower luminance have—independently—a small-to-moderate thinning effect on the perceived size of the body, and the effect is larger when the two variables are combined. In Experiment 3, we further show that the thinning effect due to the luminance of the dress is enhanced when the general background gets darker.

Keywords: size perception, horizontal stripes, luminance, Helmholtz illusion, clothes

Discussion

In the present study, we focused on the perceptual effect of horizontal stripes in clothes. Unlike most previous studies, we compared the effect of horizontal stripes against non-striped stimuli, that is, against a neutral condition. In Experiment 1, we found that participants perceived a striped dress (with light-green and black stripes) to be significantly thinner than an identical non-striped (light-green) version of the same dress, but not when compared to a non-striped black version. Since the thinning effect was significant only when the striped dress was compared to the light-green dress, we hypothesized that luminance might moderate the thinning effect. In Experiment 2, we dissociated the stripes and luminance effects by including two extra stimuli. In this way, it was possible to measure the effect of horizontal stripes and luminance on the perceived body width independently, as well as their aggregating effect. The results showed that, first, when the effect of luminance was controlled for, horizontal stripes had a thinning effect against non-striped stimuli. Second, when the effect of horizontal stripes was controlled for, stimuli with lower luminance had a thinning effect against stimuli with higher luminance, either when both stimuli were striped or non-striped. Third, when both stripes and luminance were taken together, the effect was even larger.

Although it seems that the stripes effect holds when the luminance of the stimuli and the background are held constant, the luminance of the background—against which the stimuli were placed—might have affected the thinning effect of darker stimuli. This is because, in the luminance effect, the darker (vs. lighter) stimuli were further away from the luminance of the background and this luminance difference might have affected size perception. In Experiment 3, we manipulated the background luminance (i.e., creating light, average, and dark backgrounds) to investigate whether the luminance effect of Experiment 2 was due to the increased contrast between the dark dresses and the light-grey background. The results showed that the thinning effect of dark dresses could not be attributed to stimuli-background contrast. Instead, we discovered that when the luminance of the general background is darker, the thinning effect becomes more pronounced.

The thinning effect of low luminance is in line with the irradiation illusion (Helmholtz, 1962), according to which a bright area seems larger than a darker area of similar size (Long & Murtagh, 1984; Oyama & Nanri, 1960), an effect attributable to the non-linear visual processing of dark and light both on retinal (Valeton & van Norren, 1983; Westheimer, 2008) and cortical level (Kremkow et al., 2014). On the cortical level for instance, Kremkow et al. (2014) showed that the ON and OFF neurons operate in dissimilar ways in our visual system, with the OFF neurons responding linearly to external stimuli, and the ON neurons responding in a curvilinear way (overresponding even to limited external stimulation). The practical implication is that dark stimuli are perceived as smaller than bright, not because the size of dark stimuli is underestimated, but rather because the size of bright stimuli is overestimated. As a consequence, the darker dresses in Experiments 2 and 3 were perceived as thinner presumably because participants might have overestimated the size of the brighter dresses.

So far only one study has tested the perceptual effect of horizontal stripes against non-striped stimuli. Thompson and Mikellidou (2011; Experiment 3) found that a cylinder with horizontal stripes was perceived as similar in size (neither wider nor thinner) to an identical non-striped cylinder. This finding is at odds with the results of the present experiments. Nevertheless, the present results suggest that the thinning effect of horizontal stripes seems to be consistent and strong (in terms of effect size and observed statistical power). They also suggest that the thinning effect is further decomposed into two separate effects, that is, both the orientation and the luminance of the stripes affected the perceived size of the dress, and the thinning effect of luminance was further amplified as the luminance of the background decreased.

Our results also extend and partially explain the Helmholtz illusion. In the original paradigm, a square with horizontal stripes is compared to a similar square with vertical stripes. In that context, the thinning effect of horizontal stripes cannot be attributed to luminance, since both stimuli have the same luminance regardless of stripe orientation. It can be attributed, however, to the thinning effect of horizontal stripes, as Experiment 2 showed. Whether vertical stripes also contribute to the overall effect or not, remains an open empirical question.

Future Research

The present results open two main venues for future research. The first is to further probe the boundary conditions that might account for the effect. In the present study we tested the effect of horizontal stripes, luminance, and contrast but the list of confounding variables may be longer. Some variables that might account for the effect include the orientation of the stripes (e.g., test the effect of vertical stripes against a neutral condition), their spatial frequency (the thickness of the stripes), or color. Moreover, previous studies reported that the body size moderates the effect, with bigger body types decreasing (Ashida et al., 2013) or even reversing the thinning effect of horizontal stripes (Imai, 1982). Future studies can test the effect in different body sizes and body shapes (e.g., hourglass, spoon, rectangle).

The second line of research calls for an interdisciplinary approach between the fields of social cognition (participants’ previous beliefs) and psychophysics (participants’ perception). It is striking that, although the results of the present experiments support the thinning effect of horizontal stripes, this finding clashes with participants’ beliefs and leads to a paradox: during the behavioral task in the lab participants perceived horizontal stripes in clothes as thinner, but in self-reports they stated the opposite.³ This inconsistency was also described by Ridgway et al. (2017) where they scanned the body of 15 women and their 3D avatars were presented on a computer. The avatars were dressed in horizontal stripes (and seven more optical illusions) and participants were asked to evaluate them. A thematic analysis (a qualitative in-depth interview method) revealed that a number of participants swayed away from their original negative attitude towards horizontal stripes once they saw themselves in the horizontally striped dress. Although the results of that study were based on qualitative analysis and did not provide any conclusive evidence, the discrepancy between previous beliefs and behavioral responses regarding the effect of horizontal stripes in clothes still remains.

Especially with the increasing devaluation of the other group, but also with the increasing conviction of their own position, the supporters of COVID restrictions accept restrictions regarding the others’ freedom of expression

Polarisation and Silencing others During the Covid-19 Pandemic in Germany: An Experimental Study Using Algorithmically Curated Online Environments. Tim Neumann, Ole Kelm, Marco Dohle. Javnost - The Public, Sep 10 2021. https://doi.org/10.1080/13183222.2021.1969621

Abstract: In 2020, societies debated the use of government restrictions on public life to stem the COVID-19 pandemic. Many of these debates took place online. The Internet enables people to come into contact with like-minded content. Algorithms based on collaborative filtering can contribute to this process and might lead to homogenous like-minded online environments that contribute to a polarisation of society. This article therefore examines the effects of (1) like-minded versus opposing online environments, which were (2) randomly versus algorithmically curated. Data from a between-subject experiment embedded in a two-wave panel survey of German citizens (n = 318) show that attitude polarisation as well as affective polarisation are largely independent of exposure to different online environments. Moreover, the results indicate that polarised attitudes of supporters and opponents of the COVID-19-related restrictions relate to varying degrees of beliefs in the importance of silencing people with opposing opinions: While supporters’ polarised attitudes are positively related to the belief in the importance of silencing others, opponents’ polarised attitudes are rather negatively related to such beliefs.

KEYWORDS: belief in the importance of silencing otherscollaborative filteringexperimentonline discussionpolarisationselective exposure

Discussion

One central aim of this article was to examine the effects of homogenous and algorithmically curated opinion environments on polarisation in the context of the COVID-19 pandemic. For this purpose, data from a two-wave panel survey conducted among the German population with an embedded between-subject experiment were analysed. Participants were assigned to different online environments, in which they were exposed to either (1) like-minded or (2) opposing arguments for restrictions to combat the COVID-19 pandemic. The selection of these arguments was either (1) random or (2) based on an algorithm with collaborative filtering.

The results show that the generated online environments did not influence attitude polarisation, i.e. they did not affect how certain the respondents are in terms of their respective attitudes toward the government actions. One reason for this could be that the COVID-19 pandemic is not the ideal context to test the influence of like-minded online environments and the role of algorithms as, for example, many people are most likely confronted with information on this topic outside online environments (Viehmann, Ziegele, and Quiring 2020). This potentially limits at least the short-term effects of arguments presented in online environments. Moreover, the non-existent effects regarding the selection mode must be treated with caution, as the manipulation check regarding the selection mode failed.

Another reason could be that the respondents’ attitudes toward the government actions were so pronounced that they could not even be strongly influenced by the presentation of convincing arguments. However, other explanations for these non-existent effects are possible. For example, it might not only be the content of an argument that is crucial to its persuasiveness. Instead, also in algorithmically curated online environments, how an argument is presented and whether, for example, it is presented factually, emotionally or embedded in a narrative might be (more) relevant. Even more obvious, who has authored and spread the argument might also be important. In line with the echo chamber hypothesis, other people echo one’s own opinion. Through repeated interaction, people can build a relationship with these like-minded others, giving their arguments more weight than the arguments of other people or, which seems to be relevant in the case at hand, than the arguments that are presented via an anonymous platform. In addition, people more often use the content of sources and people they trust (e.g. Strömbäck et al. 2020). As a result, and in line with the filter bubble hypothesis, algorithms with collaborative filtering are likely to select more often information from these sources or from people with whom the people in question more often interact. Thus, the impact of the authors of the arguments, which did not play a role in the presented experimental study, may be crucial.

The experimental results also show that the different online environments created in this study did not influence affective polarisation. Again, the reason could be that the respondents’ attitudes toward the other group were so pronounced that they could not be strongly influenced by the content presented via the online discussion platform. However, it might also be the case that group identification in the context of the COVID-19 pandemic is too low. Many people in Germany had an opinion on the government actions, but they might not have seen themselves as part of a specific group—maybe also because they recognised that (almost) the entire population was and is affected by the consequences. This makes affective polarisation as a consequence of arguments that were presented only once more unlikely. More likely, affective polarisation may occur as a consequence of observing behaviour that one disapproves of (e.g. ignoring restrictions on demonstrations). Another explanation is that the presented arguments were within the democratic spectrum of opinion and did not contain, for example, incivility, exaggeration or satirical elements. These elements may trigger affective polarisation more strongly than the direction of an argument (Druckman et al. 2019).

Another central aim of the study was to examine how attitude polarisation and affective polarisation are related to the BISO. The study shows that affective polarisation among the opponents of restrictions is rather negatively related to the BISO. In view of previous research results (Tsfati 2020), this may initially be surprising. However, it is conceivable that the opponents of the restrictions consider the restrictions as an unreasonable limitation of their fundamental rights. Since they perceive their fundamental rights as already being restricted, they might fear further restrictions of such rights. If they themselves silence other groups, this will lead to cognitive dissonance, which they want to avoid. Moreover, as there are no short-term political majorities for their demands, they are, compared to the supporters of restrictions, more dependent on a public debate that is as open and broad as possible.

For supporters of the COVID-19-related restrictions, however, the results were different: Especially with the increasing devaluation of the other group, but also with the increasing conviction of their own position, the supporters of restrictions want to prevent positions perceived as dangerous from being spread—for this reason, they also accept restrictions regarding the others’ freedom of expression. The differences between the supporters and the opponents of the restrictions can also be explained by the object of silencing: Tsfati and Dvir-Gvirsman’s (2018) understanding of the BISO focuses on interpersonal communication—whether face-to-face or in online environments. From the point of view of the opponents, there are reasons to support a broad public debate (which, of course, includes all forms of interpersonal communication), whereas from the point of view of the supporters of the restrictions, there are reasons to limit this public debate to acceptable contributions. If silencing had been applied to journalism or authorities, the results might have been different.

The study has limitations. Although government restrictions and incidence numbers in Germany changed little during the fieldwork, many people’s opinions toward the restrictions changed. The results of the control group of this study also illustrate this: In total, 21.9 per cent of the respondents assigned to the control group changed their opinion toward the restrictions from t1 to t2. Thus, the time gap between t1 and t2 may be responsible for the fact that arguments selected by the algorithm were not (more) convincing. This also became apparent in the manipulation check, which did not show a significant difference in the persuasiveness of the arguments that were randomly selected and those that were selected by the algorithm.

Second, the respondents were only briefly exposed to the stimulus. This may have reduced its effects. This might be especially true for the chosen topic, about which most people have probably received extensive information via many sources. Further studies should examine the effects of different online environments in other polarised contexts that are less in the media spotlight (e.g. genetically modified food).

Third, the respondents were not able to choose which online environment they entered (“forced exposure”), and forced and self-selective exposure might have different effects on polarisation (e.g. Arceneaux and Johnson 2013).

Fourth, as the results of the regressions are based on cross-sectional data, no causal claims can be made, which is why no mediation models were calculated (see Chan, Hu, and Mak 2020), even if the results suggest potential mediation effects. The results imply that attitude polarisation has an effect on the BISO and that this effect is mediated by affective polarisation. To test these assumptions, experimental studies should (1) manipulate attitude polarisation to analyse its potential effect on affective polarisation and the BISO and (2) manipulate affective polarisation to analyse its potential effect on the BISO.

Finally, we only focused on one country. Thus, it is unclear whether the results are generalisable to other contexts.

Despite these limitations, the present study contributes to current research on how like-minded and opposing online environments influence polarisation. Even though it cannot be ruled out that the non-existent findings are due to the experimental set-up, it is also possible that the results indicate that the process of how like-minded or opposing information influences polarisation is more complex than previously suspected. More studies are needed that focus on the potential effects of being exposed to these online environments. Experimental studies using algorithmically curated stimuli may be helpful to determine the effects. Furthermore, this study has shown that the BISO is a theoretical concept that is also relevant in more (national) contexts than those previously tested (e.g. Tsfati 2020). Silencing others and the belief in the importance of doing so may be important concepts for understanding polarised societies.

Sex differences in total brain volume are not accounted for by sex differences in height and weight, and that once global brain size is taken into account, there remain numerous regional sex differences in both directions

Sex differences in the brain are not reduced to differences in body size. Camille Michèle et al. Neuroscience & Biobehavioral Reviews, September 11 2021. https://doi.org/10.1016/j.neubiorev.2021.09.015

Abstract: In their comprehensive review of sex differences in the brain, Eliot et al. (2021) conclude that (1) men and women significantly differ in global brain size, but this “mostly parallels the divergence of male/female body size during development” and that (2) “once we account for individual differences in brain size, there is almost no difference in the volume of specific cortical or subcortical structures between men and women”. In sum, almost all brain differences would directly or indirectly follow from differences in body size. In a recent study that does not have the same limitations as most studies reviewed by Eliot et al., we find that sex differences in total brain volume are not accounted for by sex differences in height and weight, and that once global brain size is taken into account, there remain numerous regional sex differences in both directions (Williams et al., 2021).

Keywords: sex differencesBrain VolumesCortical Mean ThicknessesCortical Surface Areas

Adoptive & biological families with 30-year-old offspring: Proportion of variance in IQ attributable to environmentally mediated effects of parental IQs was estimated at .01; heritability was estimated to be 0.42

Genetic and environmental contributions to IQ in adoptive and biological families with 30-year-old offspring. Emily A. Willoughby, Matt McGue, William G. Iacono, James J. Lee. Intelligence, Volume 88, September–October 2021, 101579. https://doi.org/10.1016/j.intell.2021.101579

Highlights

• Genetic and environmental sources of variance in IQ were estimated from 486 adoptive and biological families

• Families include 419 mothers, 201 fathers, 415 adopted and 347 biological fully-adult offspring (M age = 31.8 years; SD = 2.7)

• Proportion of variance in IQ attributable to environmentally mediated effects of parental IQs was estimated at .01 [95% CI 0.00, 0.02]

• Heritability was estimated to be 0.42 [95% CI 0.21, 0.64]

• Parent-offspring correlations for educational attainment polygenic scores show no evidence of adoption placement effect

Abstract: While adoption studies have provided key insights into the influence of the familial environment on IQ scores of adolescents and children, few have followed adopted offspring long past the time spent living in the family home. To improve confidence about the extent to which shared environment exerts enduring effects on IQ, we estimated genetic and environmental effects on adulthood IQ in a unique sample of 486 biological and adoptive families. These families, tested previously on measures of IQ when offspring averaged age 15, were assessed a second time nearly two decades later (M offspring age = 32 years). We estimated the proportions of the variance in IQ attributable to environmentally mediated effects of parental IQs, sibling-specific shared environment, and gene-environment covariance to be 0.01 [95% CI 0.00, 0.02], 0.04 [95% CI 0.00, 0.15], and 0.03 [95% CI 0.00, 0.07] respectively; these components jointly accounted for 8% of the IQ variance in adulthood. The heritability was estimated to be 0.42 [95% CI 0.21, 0.64]. Together, these findings provide further evidence for the predominance of genetic influences on adult intelligence over any other systematic source of variation.

Keywords: IntelligenceAdoptionHeritabilityVocabularyPolygenic scores

Asking the mayor's office how to start a business: Chinese & German cities responded to 36-37% requests; American cities responded to 22%; Chinese cities were more responsive to requests from men

Köhler, Ekkehard A. and Matsusaka, John G. and Wu, Yanhui, Street-Level Responsiveness of City Governments in China, Germany, and the United States (August 19, 2021). SSRN: http://dx.doi.org/10.2139/ssrn.3907862

Abstract: This paper presents evidence from parallel field experiments in China, Germany, and the United States. We contacted the mayor’s office in over 6,000 cities asking for information about procedures for starting a new business. Chinese and German cities responded to 36-37 percent requests; American cities responded to only 22 percent of requests. We randomly varied the text of the request to identify factors that affect the likelihood of receiving a response. American and German cities were more responsive to requests from citizens than foreigners; Chinese cities did not discriminate on this basis. Chinese cities were more responsive to requests from men than women; German cities did not discriminate on this basis and American cities had a slight bias in favor of women. Cities in all three countries were more responsive to requests associated with starting a construction business than a green business, but especially Chinese cities. Chinese cities were more responsive when the mayor was being considered for promotion than after a promotion decision, suggesting the importance of promotion incentives in China, but low responsiveness to green investment suggests limited incentives for environmental improvement. We argue that the response patterns are consistent with simple political economy theories of democracy and autocracy.

Keywords: Responsiveness, bureaucracy, democracy, autocracy, environment, discrimination, China, Germany

JEL Classification: H7, H83, O38, P5, R5

Older Taiwanese people had slower processing speeds than their US peers; younger Taiwanese people had faster processing speeds than their US peers; physiological, environmental, and genetic factors contribute

Development of processing speed in the United States and Taiwan: A brief report. Hsinyi Chen, Yung-Kun Liao, Richard Lynn. Personality and Individual Differences, Volume 184, January 2022, 111227. https://doi.org/10.1016/j.paid.2021.111227

Highlights

• We compared processing speed using collective US and Taiwanese data.

• Older Taiwanese people had slower processing speeds than their US peers.

• Younger Taiwanese people had faster processing speeds than their US peers.

• Physiological, environmental, and genetic factors contribute to these differences.

Abstract: Processing speed is a critical component of intelligence, and an important cognitive ability in the facilitation of human learning. Previous studies have examined the development of processing speed across cultures. This study investigated processing speed performance using collective data from standardized Wechsler scales in the United States and Taiwan from the past two decades. Drawing comparisons between national norms from ages 4 to 80 years, the results revealed that older people in Taiwan recorded slower processing speeds than their US counterparts. Conversely, younger people in Taiwan recorded faster processing speeds than their US counterparts. This evidence shows that physiological, environmental, and genetic factors contribute to group differences in the development of processing speed.

Keywords: AgeCross-cultural comparisonIntelligenceProcessing speedWechsler tests

Helping behavior, bystander intervention, violence, emergency, danger, systematic video observation

Does Danger Level Affect Bystander Intervention in Real-Life Conflicts? Evidence From CCTV Footage. Marie Rosenkrantz Lindegaard et al. Social Psychological and Personality Science, September 9, 2021. https://doi.org/10.1177/19485506211042683

Abstract: In real-life violence, bystanders can take an active role in de-escalating conflict and helping others. Recent meta-analytical evidence of experimental studies suggests that elevated danger levels in conflicts facilitate bystander intervention. However, this finding may lack ecological validity because ethical concerns prohibit exposing participants to potentially harmful situations. Using an ecologically valid method, based on an analysis of 80 interpersonal conflicts unobtrusively recorded by public surveillance cameras, the present study confirms that danger is positively associated with bystander intervention. In the presence of danger, bystanders were 19 times more likely to intervene than in the absence of danger. It extends this knowledge by discovering that incremental changes in the severity level of the danger (low, medium, and high), however, were not associated with bystander intervention. These findings confirm the importance of further investigating the role of danger for bystander intervention, in larger samples, and involving multiple types of real-life emergencies.

Keywords: helping behavior, bystander intervention, violence, aggression, emergency, danger, systematic video observation

Discussion

The results provide support for a discrete effect of danger on bystander intervention. The odds of bystander intervention are 19 times higher when conflict parties display targeted aggression than when they do not. This result is in line with theories of altruism and prosocial behavior that suggest that increases in potential harm motivate bystander interventions. It is also in line with studies suggesting that the urgency of the need for help facilitates intervention. However, we also found that the aggression intensity level did neither facilitate nor deter bystander intervention. Serious forms of aggression were not more likely to provoke bystander intervention than minor forms of aggression. This finding runs counter the idea that increased danger boosts the motivation to intervene because nonintervention might be experienced as a too high cost in serious danger situations. It also runs counter the idea that increased danger reduces the bystanders’ motivation to intervene for fear being of harmed themselves in the act of intervention. A potential explanation for the absence of overall aggression intensity effect in our findings is that the two mechanisms that stimulate and deter intervention in response to danger might cancel out. According to this argument, increasing danger raises the benefits of intervention by reducing victim harm, while simultaneously raising the costs of intervention by increasing bystander harm. In nonexperimental conflict situations, danger affects the risks for victims and bystanders alike. Therefore, our observational data cannot disentangle both mechanisms. Another, less substantive but possible, the explanation is that our observational design lacks the statistical power to identify the effects of low and high aggression levels because these levels occur infrequently in the data (eight intervals with low aggression and seven intervals with high aggression) whereas medium aggression is much more common (45 instances of medium aggression). A larger sample size would be needed to identify potential effects of low and high aggression levels and to also demonstrate differences in the effects sizes of all three aggression levels.

Our within-person design rules out all stable between-person and between-situation confounders as explanations for these mixed results but unobserved time-varying factors such as, for example, changes in the communication of urgency could play a role. We found no moderating effect of the number of bystanders present, preexisting social relationships, and gender on the effect of danger on bystander intervention. In Amsterdam, interveners responded more strongly to variation in aggression level than in Cape Town. Future studies should consider the effect size of danger compared to stable personal and situational characteristics of conflict situations, for example, evaluate the extent to which bystander intervention is driven by dynamic or stable factors. They should also consider whether the danger has a different confounding effect on different kinds of individuals (e.g., Do people with low self-control vs. high self-control respond similarly to danger?) and in different kinds of situations (e.g., Does danger also facilitate bystander intervention in, for example, robberies and sexual assaults).

A limitation of our aggression-level measures is that they are objective physical actions and exclude verbal communications. Obviously, bystanders respond to subjective impressions, and their actions may be driven by expectations based on threats or other verbal expressions that we could not capture and thus could not code as aggression. Future studies might improve on the measurement of aggression by using footage that includes sound, for example, from body-worn camera footage, and by considering the communication of urgency other than aggression. Another limitation of our study is that we operationalize bystander intervention to physical actions aimed at stopping the conflict, while bystanders engage in nonphysical intervention behavior too, including more indirect ways of intervening such as phoning the police. Future work could also improve our test of the effect of danger on bystander intervention by including more high-intensity cases (in the current study, we only had seven incidents in which the highest aggression level was observed), for example, those with visible injuries or use of weapons. Future studies should consider the role of danger for various types of bystander intervention behavior.

In summary, we conclude that bystanders are more likely to intervene when danger is present than when danger is absent but that there is not enough evidence to conclude that the intensity of the danger makes their intervention either more or less likely.

Centenarians: 31.4% expressed willingness to live longer, 30.6% did not, & 38% presented no clear positioning; annoyance, uselessness, loss of meaning, disconnection, & loneliness were common justifications for reluctance

To Live or Die: What to Wish at 100 Years and Older. Lia Araújo et al. Front. Psychol., September 10 2021. https://doi.org/10.3389/fpsyg.2021.726621

Abstract: Previous research has shown that will to live is a strong predictor for survival among older people, irrespective of age, gender, and comorbidities. However, research on whether life at age 100 is perceived as worth living is limited. The available literature has presented evidence for good levels of positive attitudes and life satisfaction at such an advanced age, but it has also suggested that a longing for death is common. This study aimed to add to the existing data on this matter by exploring centenarians' will to live and the associated factors. The sample comprised 121 centenarians (mean age, 101 years; SD, 1.63 years), 19 (15.7%) of whom were males, from two centenarian studies (PT100). Answers to open questions were analyzed to identify the centenarians' will to live and the reasons behind it. Three groups were created (willing to live longer, not willing to live longer, no clear positioning) and further analyzed in terms of sociodemographic characteristics, health status, social functioning, and well-being. Of the total sample, 31.4% expressed willingness to live longer, 30.6% did not, and 38% presented no clear positioning. The presence of the Catholic religion (God) was referred for centenarians in all three groups. Annoyance, uselessness, loss of meaning, disconnection, and loneliness were the most common justifications for being reluctant to live longer. Positive valuation of life and good self-rated health, followed by having a confidant and reduced pain frequency, were the factors associated with being willing to live longer. The results of the study contribute to the understanding of the psychological functioning of individuals with exceptional longevity, particularly concerning the factors behind willingness to live at such an advanced age.

Discussion

Centenarians are an elite group, significantly exceeding the average life expectancy. This study explored the will to live and associated factors in a sample of these long-lived individuals by considering both quantitative indicators and qualitative data. The number of participants willing and unwilling to live longer was similar (31%) but lower than those without clear positioning (38%). Compared with the findings of studies of preferred life expectancy that also considered a non-response group, this was a very high percentage. For instance, in a study of 1,631 younger and middle-aged adults, Bowen and Skirbekk (2017) found that 15.9% of the sample did not clarify their preferred life expectancy. However, due to the lack of studies similar to the present one, whether the greater percentage was related to the centenarians' characteristics or the methodology of the study cannot be determined. Nevertheless, this group may have represented a stoic mindset in which individuals express a valuation of life per se and “as it comes” with discomfort or unwillingness to reflect about lifetime extension (Lang and Rupprecht, 2019).

Still, the qualitative exploration of this group's answers showed that almost everyone justified their lack of answer/positioning by mentioning God, stating that their remaining time to live was a matter that was not in “their hands” (i.e., one they could not control). This follows the idea that a sense of control through the sacred may come when life seems out of control (Wong et al., 2014). Although a sense of control is recognized as an important source of human life-strength, individuals who accept that declining control over environment comes with aging and focus on their ability to control their own internal states and behaviors demonstrate a more successful adjustment to aging (Hyer et al., 2011). Indeed, this group presented a satisfaction with life score very close to the group reporting willingness to live longer.

Regarding the reference to God, which was also present in the other two groups, religion and spirituality play an important role in the lives of older adults, as they help older people find meaning in later life (Frankl, 1963; Atchley, 2009; Wong et al., 2018) and are thus associated with how long one desires to live (Lang and Rupprecht, 2019). Different studies focusing on the centenarian population have confirmed the positive impact of religion and spirituality in well-being, which may be even more significant since this age group may fail to derive basic resources (Bishop, 2011). Archert et al. (2005) found that religiosity was one of the major themes that emerged from a qualitative analysis about adaptation and coping in the lives of centenarians; when asked about the most important thing in their lives, 58% of the respondents mentioned church and/or God. Interestingly, a female centenarian shared a sentence very similar to one of the participants in the present study, arguing that the future is held in God's hands (Archert et al., 2005). Furthermore, Manning et al. (2012) found that centenarians place considerable importance on divine support in their lives. This study found an interconnectedness of spirituality with religion for centenarians; in other words, these two constructs overlap. Through a phenomenological examination of life-satisfaction and compensatory strategies in Jewish-Canadian centenarians, Milevsky (2021) found that compensatory, cultural, and religious processes were imbued into several of the themes, such as “Maintaining connections with family, friends, and God” (p. 101) and “Remaining positive and kind” (p. 104). It is expected to have an intrinsic need to have hope that goes beyond this life and have faith either in something or in someone, which can be religiously oriented or without any religiosity (Saarelainen et al., 2020). But the huge presence of religion in centenarians' discourses found in the present study may echo the importance of church and military in shaping the lives of this older Portuguese generation (Birmingham, 2003), as well as the overall impact of religious beliefs, practices, and culture (Boerner et al., 2019).

The quantitative results of the present study revealed the significant contribution of health (pain frequency and SRH), social functioning (friends as confidants), and well-being (positive valuation of life). These findings confirmed that will to live is the summation of individuals' biopsychosociospiritual dimensions (Bornet et al., 2021) and depends on both external (e.g., social networks) and intra-personal factors (e.g., health and self-perceptions; Lawton et al., 1999). No sociodemographic variable was found to be relevant, which agreed with the findings of a scope review on will to live conducted by Bornet et al. (2021). Positive VOL had the strongest significant association with will to live, which was expected. Despite the great importance being attributed to variables like physical and health functionality in longevity and quality of life (Rowe and Kahn, 1997), some studies have emphasized the importance of psychological functioning and well-being, especially for very old individuals. For instance, a comparison of components in the World Health Organization's (WHO) active aging model by age group (< 75 years vs. ≥ 75 years) revealed the major relevance of the psychological component to the older age group (Paúl et al., 2017). Likewise, the operationalization of the successful aging model (Rowe and Kahn, 1997) in centenarians revealed the importance of subjective appraisals and psychological variables (Araújo et al., 2016).

The fact that the number of health conditions and levels of fatigue and functional capacity presented no significant association with will to live in this study supported the argument that individuals with problems related to physical health and functioning may be able to maintain subjective well-being. This agreed with the paradox of well-being, i.e., reporting experiences of positive psychological functioning despite decline in physical health, as the evidence of resilience in old age (Wiesmann and Hannich, 2014). Interestingly, pain and SRH, the two health factors with a significant impact on will to live, have also been associated with resilience in centenarians (Amaral et al., 2020). Gu and Feng (2018) argued that higher resilience could yield a greater protection for SRH and life satisfaction among centenarians compared with younger elderly groups. Thus, resilience may also be associated with will to live, as identified in younger groups (Bornet et al., 2021). This was supported by the qualitative analysis; aspects related to health, such as dependency, sense of burden, and fear of suffering, were referred to less than uselessness, annoyance, and loss of meaning by centenarians who were unwilling to live longer.

In advanced age, some aspects of purpose in life are more difficult to fulfill, such as having goals for the far future or feeling useful (Pinquart, 2002). This study found that these variables continue to be very important, specifically for (un)willingness to live. Conversely, will to live has strong, direct effects on well-being, including life and aging satisfaction (Jopp et al., 2017). The large influence of positive VOL on will to live meets Lawton et al.'s (1999) assumptions (i.e., years of desired life are mediated by VOL) in an age group in which this issue was not studied. Both existential beliefs and perceived control were higher in the group willing to live longer—that is, they represented important aspects for centenarians' reason for living, even under difficult conditions of functional impairment and disease. This confirmed that a “possible mechanism for the potency of VOL as a determinant of Years of Desired Life is the ability of people to adjust their standards for what is acceptable in everyday life in accord with changes in both their personal characteristics and the circumstances under which they live” (Lawton et al., 2001, p. 25).

Social factors also seem to have a contribution to will to live (Bornet et al., 2021), being an important source of meaning in life among older people (Saarelainen et al., 2020). Social relationships and support may be particularly important for centenarians (Boerner et al., 2016). The loss of friends and relatives that is typical in these long-lived individuals can make social contacts even more significant by reducing opportunities for (intra- and intergenerational) relationships (Randall et al., 2010). In the present study, the only social variable significantly associated with will to live was the number of friends as confidants. Thus, support—rather than size—may be the most significant aspect of social networks. Previous studies of the oldest old have shown the importance of having a close friend for independence (Pin et al., 2005) and well-being (Johnson and Barer, 1997). Indeed, maintaining a confidant is suggested as a strategy that centenarians use to compensate for losses and increase well-being (Araújo and Ribeiro, 2012). From the qualitative data, (social) disconnection and loneliness emerged as an important motive for losing will to live, as was also the case of feeling like a burden.

This last reason, which is typically referred to in studies on will to live (Bornet et al., 2021) since its related to the high burden of taking care of a person in the end of life, shows the need to acknowledge those who are supporting centenarians. The few studies that investigated will to live and end of life issues in centenarian's caregivers and offspring indicated concerns of family members that they'd become a burden for caregivers and would face the unavailability of family support if they became centenarians (Brandão et al., 2019). The fact that caregivers value this aspect so much, reinforces their potential burdens and needs. If being willing to live at 100 years old depends on the availability of social support, more must be invested in these caregiving offspring who are confronted with their own advanced age and the burdens of their parents' very old age (Eggert et al., 2020).

Despite the richness of this study's findings, some limitations should be considered. The cross-sectional design of the study prevented the ability to determine the direction of the relationships between variables, which could be of particular interest in this topic since willingness to live could be a predictor of well-being. Furthermore, those who shared their opinion (i.e., mostly individuals with mild or no cognitive impairment) represented only a part of the original sample, so these findings should not be generalized to the centenarian population.

Higher nut intake was associated with reductions in body weight and body fat; current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted

Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose–response meta-regression of prospective cohorts and randomized controlled trials. Stephanie K. Nishi, Effie Viguiliouk, Sonia Blanco Mejia, Cyril W. C. Kendall, Richard P. Bazinet, Anthony J. Hanley, Elena M. Comelli, Jordi Salas Salvadó, David J. A. Jenkins, John L. Sievenpiper. Obesity Reviews, September 8 2021. https://doi.org/10.1111/obr.13330

Summary: Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. A systematic review and meta-analysis of prospective cohorts and randomized controlled trials (RCTs) was conducted to update the evidence, provide a dose–response analysis, and assess differences in nut type, comparator and more in subgroup analyses. MEDLINE, EMBASE, and Cochrane were searched, along with manual searches. Data from eligible studies were pooled using meta-analysis methods. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Certainty of the evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Six prospective cohort studies (7 unique cohorts, n = 569,910) and 86 RCTs (114 comparisons, n = 5873) met eligibility criteria. Nuts were associated with lower incidence of overweight/obesity (RR 0.93 [95% CI 0.88 to 0.98] P < 0.001, “moderate” certainty of evidence) in prospective cohorts. RCTs presented no adverse effect of nuts on body weight (MD 0.09 kg, [95% CI −0.09 to 0.27 kg] P < 0.001, “high” certainty of evidence). Meta-regression showed that higher nut intake was associated with reductions in body weight and body fat. Current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.

4 DISCUSSION

The present systematic review and meta-analysis of nut consumption and adiposity involving six prospective cohort studies and 86 RCTs (114 trial comparisons) did not illustrate an increased risk of overweight/obesity or raise other measures of adiposity studied in adults.

Based on the long-term findings from the prospective cohort studies, a significant inverse association was observed across outcomes assessed. These findings align with those proposed by the systematic review of prospective studies by Eslami and colleagues.35 Suggesting that nut consumption may have a protective effect on risk of adiposity accumulation. This is further supported by the results of the present aggregate analyses from the RCTs, which showed a lack of a causal effect of nut consumption on the reported measures of adiposity. Previous systematic reviews and meta-analyses of trials involved differing inclusion and exclusion criteria yet showed similar findings in regard to a lack of effect of nut consumption on body weight, BMI, or waist circumference.36, 37 The lack of effect of nut consumption on waist circumference is further supported by Blanco Mejia and colleagues in their systematic review and meta-analysis assessing nuts and metabolic syndrome.3

Significant heterogeneity in the current analysis did exist. While this heterogeneity could not be adequately assessed categorically for the cohorts as there were too few cohort studies, subgroup analyses and meta-regression of the trials identified potential sources of heterogeneity. For the trials, similar to the previous publications,36, 37 energy balance was identified as a potential source of heterogeneity. However, in the current analysis, incorporating nuts into a dietary pattern involving an overall negative energy balance compared to a negative energy balance without nuts was observed to favour nuts in regard to not increasing body weight, BMI, or waist-to-hip ratio. Inclusion of nuts as a part of a dietary pattern without concern for increased body weight or adiposity measures is further supported by findings from the PREDIMED trial, where inclusion of nuts as part of a Mediterranean dietary pattern saw slightly reduced body weight and adiposity measures with no significant differences when compared with the Mediterranean dietary pattern with olive oil or the low fat dietary pattern.144 A sensitivity analysis involving the inclusion of the PREDIMED trial did not significantly affect the magnitude or direction of the current findings. In addition to energy balance, nut dose was detected as a potential effect modifier of body weight and body fat, where greater reductions were observed with increasing nut dose. In categorical analyses, nut doses ≥45.5 g/day indicated lower adiposity measures compared to lower doses. As nut doses of 1 to 1.5 ounces (~28 to 42.5 g) per day are often noted in dietary guidelines, as well as the FDA qualified health claim for coronary heart disease risk reduction, this suggests the provision often seen following nut recommendations, as well as stated at the end of the applicable qualified health claims asserting “see nutrition information for fat [and calorie] content” with the implied message that foods high in fat and calories lead to increased adiposity may be unwarranted.17-19 Likewise, continuous linear meta-regression identified dose-dependent relationships between nut consumption with both body weight and body fat, where nut dose was inversely correlated with body weight and fat. However, significant departures from linearity were observed in BMI, waist circumference, and waist-to-hip ratio, where the maximum protective dose appeared to be around 50 g/day based on waist-to-hip ratio. Although the waist-to-hip ratio may have been confounded by the nonsignificant positive correlation observed between waist circumference and nut consumption. This positive association between nut consumption and waist circumference differs from findings in the literature, where nut and seed consumption has been associated with significantly decreased pericardial fat, and trends toward decreased visceral fat,145 and monounsaturated fat intake, which is prevalent in nuts, compared to carbohydrate intake has been shown to prevent central fat redistribution.146

4.1 Strengths and limitations

Strengths of the present systematic review and meta-analysis include its comprehensive design, comprising both prospective cohort studies and RCTs, using the GRADE approach to evaluate the certainty of evidence. The prospective cohort studies provide assessment of nut consumption over the long term in a large sample of participants in free-living conditions in relation to adiposity. The design of RCTs provides the best protection against bias; there were also a substantial number of trials identified (106 trial comparisons) for the primary outcome of body weight; the median follow-up period was 8 weeks, which allows for the assessment of a moderate duration of intervention. In addition, the meta-regression and subgroup analyses provide further insight as to various factors that have previously been hypothesized to influence the impact of nut consumption on adiposity.

These analyses are not without limitations. For the prospective cohort studies, we downgraded the certainty of the evidence for serious inconsistency in the estimates across the studies for body weight change as there was evidence of unexplained heterogeneity (92%). Although the inconsistency may have related to measurement error as there was a lack of repeated measurement of intake of nuts, use of a food frequency questionnaire measure that was not specifically validated for nut intake, and adiposity measures were mainly self-reported by participants. Risk of bias was also observed for body weight change as participants were primarily comprised of well-educated individuals, many of whom were health professionals, including university graduates from SUN and health professionals recruited from NHS, NHS II, and HPFS, and thus may not be generalizable to other populations.

For the RCTs, we downgraded the certainty of evidence for serious inconsistency in the estimates due to unexplained heterogeneity in all the outcomes assessed, except BMI. Subgroup analyses indicated potential sources of heterogeneity; however, this was often observed when the covariate was unevenly distributed, as well as the differences in treatment effects between subgroups are unlikely to otherwise alter clinical decisions.

Weighing these strengths and limitations using GRADE, the certainty of evidence ranged from “very low” to “high.” A reason for the “very low” certainty of evidence observed is due to the GRADE approach starting observational studies at “low” certainty. Overall, the prospective cohort studies showed mostly “moderate” and the RCTs showed equally “high” and “moderate” certainty of evidence.

4.2 Potential mechanisms of action

There are several biological mechanisms which may explain the association, more specifically, the lack of association observed between nut consumption with overweight/obesity risk and other measures of adiposity, including: (1) unsaturated fatty acid content, (2) satiating effect, and (3) physical structure, each in a way associated with the bioavailability of nuts when consumed. Nuts are rich in unsaturated fatty acids (monounsaturated fatty acids [MUFAs] and polyunsaturated fatty acids [PUFAs]), which are suggested to be more readily oxidized147 and have a greater thermogenic effect148 compared to saturated fatty acids, leading to less fat accumulation. Nuts are also rich in protein and fiber and dietary components associated with increased satiety.149-151 In addition to the protein and dietary fiber content of nuts, the physical structure may also contribute to their satiating effect since the mastication process involved in mechanically reducing nuts to a particle size small enough to swallow activates signaling systems that may modify appetite sensations.152 The physical structure of nuts may also contribute to fat malabsorption due to the fat content in nuts being contained within walled cellular structures that are incompletely masticated and/or digested.153-156 Thus, due to these biological mechanisms which may be associated with decreased bioavailability, the Atwater Factor, a system for determining the energy value of foods which was founded over a century ago, associated with nuts, may overestimate the calories obtained by the body from nut consumption by approximately 16% to 25% depending on the nut type and form.157-159 This may potentially explain the present findings of a protective effect of nut consumption on measures of adiposity.

4.3 Practical implications

Current clinical practice guidelines already suggest the incorporation of nuts for the improvement of glycemic control and cardiovascular risk factors; however, there are often qualifiers regarding their fat content and energy density.14-16 With overweight and obesity respectively affecting 39% and 13% of adults globally and increased adiposity being a modifiable risk factor for diabetes and cardiovascular diseases, body weight management is an important consideration in dietary and lifestyle recommendations.160 Evidence from this systematic review and meta-analysis suggests that nuts may continue to be highlighted as a nutrient dense component of dietary patterns for their cardiometabolic benefits without concerns of an adverse effect on weight control. Nuts are currently recommended as part of the Mediterranean, Portfolio, and DASH dietary patterns, yet despite tree nut and peanut intake increasing over the past 10 years, intake worldwide remains low at an estimated 16.7 g/day with about 15.2 g being contributed by peanuts.20 This is far below current recommendations of 1 to 1.5 ounces per day (approximately 28.3 to 42.5 g/day).6, 17-19 Based on the median nut intake in the trials of the current analyses and FDA qualified health claims, a dose of 42.5 g/day of nuts could easily be integrated into a daily dietary pattern by incorporating them into meals and/or consuming them as snacks. Except for individuals with nut allergies, no increase in side effects compared with control groups was reported in any of the cohort studies or trials, suggesting that dietary patterns which incorporate nuts as a regularly consumed component are safe. Future research may further assess the impact of different varieties of nuts and formats in which they may be consumed and how they are incorporated into the diet.