A Research Note: Happiness by Age is More Complex than U-Shaped

Happiness varies with age, but there is no general agreement regarding the feature of the variation. Many studies have found that it is U-shaped such that there is a minimum between approximately 40 and 50 years of age. The result largely depends on the control variables used in the happiness modeling. Some authors do not even allow the use of any control variables, but the conventional theory of U-shaped studies stipulates the inclusion of such controls that essentially influence the basic living conditions of people. In this study, we do not strictly follow earlier findings but estimate our age-shape with different versions of them, using the data of 28 or 30 European countries. We also estimate a model without proper controls. This does not give any minimum age and thus supports some studies. Moreover, using any or all of our three controls some type of U-shape is found in most countries. Our U-shapes are not as simple as conventional research suggests. Minimum happiness can occur either below 40 years, or much above 50 years. A special feature is that the U-shape phenomenon holds better for males than for females. We also estimated models to see what happens after the minimum age happiness. In the case of gender models, the turning points for males are substantially lower than for females. This means that the old-age happiness of males stops to increase approximately at 70 years but more than 10 years later for females.     

What Affects Happiness Inequality? Evidence from Japan

This paper examines the determinants of happiness inequality in Japan using unique data from the “Preference Parameters Study” of Osaka University, a nationally representative survey conducted in Japan. By estimating Recentered Influence Function regressions, we find that household income has a negative and significant effect on happiness inequality, as found for other advanced economies, though people’s perception of their relative standing in the income spectrum also matters for the dispersion of happiness. Moreover, the regression results show that the insecurity faced by people about their jobs and life after retirement is also significantly associated with the widening of happiness inequality. Such findings are cause for grave concern given that the share of irregular jobs, which tend to be low paid and insecure, in total employment significantly increased in Japan during the Lost Two Decades and that this increasing trend has not yet been reversed.     

What Does “Happiness” Prompt in Your Mind? Culture,Word Choice,and Experienced Happiness

What three words come to your mind in association with “happiness”? We analyzed the 1563 words reported by 521 Korean and American participants in this free association task. The most frequently endorsed word was “family” in Korea, whereas the most popular word among Americans was “smile.” The overall frequency of social words (e.g., relationships, social emotions) reported by Koreans was higher, and the most often mentioned relationship type differed between the two groups (family in Korea; friend in the US). Nonetheless, both in Korea and the US, individuals who mentioned more social words were significantly more satisfied with their lives. The amount of social support provision mediated the link between the number of reported social words and experienced happiness. Regardless of culture, a simple count of social words associated with happiness appears to offer a reasonably good clue for how happy the person actually is.     

The Mystery of Chinese People’s Happiness

The great improvement in economic wealth and social welfare over the decade doesn’t promote the Chinese people’s happiness. We construct a theoretical framework which covers economic wealth, social welfare, individual functional capability to explore the impact factors and determinants of the Chinese people’s happiness. Based on a national wide questionnaire survey in China, we test and modify the framework by the method of structural equation model. The empirical findings indicate that there are direct and indirect effects on the formation of happiness. For the direct effect, both the increasing of economic wealth and social welfare improves the national happiness, while the individual functional capability reduces it. For the indirect effect, the individual functional capability also reduces happiness by negatively affecting economic wealth and social welfare. The negative effect that played by individual functional capability overwhelms the positive effect played by economic wealth and social welfare. This causes the Chinese people’s happiness goes down while the economic wealth and social welfare are improving. Finally, we conclude that the Chinese people’s happiness is more about individual functional capability rather than social welfare or economic wealth.     

Personal Growth of Mothers of Preterms: Objective Severity of the Event,Subjective Stress,Personal Resources,and Maternal Emotional Support

This prospective study investigated the personal growth of Israeli mothers of premature babies at two medically defined risk levels (infants at low risk, n = 42; infants at moderate-high risk, n = 52), examining the contribution to the five dimensions of personal growth of objective event characteristics (baby’s risk level), perceived levels of mother’s stress (linear and curvilinear associations), and mother’s personal resources (self-esteem, attachment styles, perceived emotional support from her own mother). In addition, the role of the event severity as a moderator of the association between perceived maternal emotional support and personal growth was explored. Findings indicate that mothers in the two risk groups did not differ in level of perceived stress. Mothers of infants at moderate-high risk, however, experienced more spiritual change. In addition, consistent curvilinear associations emerged between perceived levels of stress and personal growth for three dimensions of growth: new possibilities, personal strength, and relations with others (with a similar trend for appreciation of life). Thus, mothers reporting moderate stress levels experienced the highest personal growth. Finally, risk group played a moderating role in the association between perceived maternal emotional support and personal growth on the dimensions of new possibilities, personal strength, and relations with others. On these dimensions, only among mothers of low-risk babies were higher levels of maternal emotional support associated with greater personal growth. The results highlight the importance of the subjective experience and the value of maternal emotional support for the personal growth of mothers of preterms. These findings may help in designing measures to identify populations at risk and developing appropriate interventions, as well as impact on the working procedures and support currently offered in most neonatal intensive care units.     

Crucial information for efficient face searching by humans and Japanese macaques

Humans can efficiently detect a face among non-face objects, but few studies of this ability have been conducted in animals. Here, in Japanese macaques and humans, we examined visual searching for a face and explored what factors contribute to efficient facial information processing. Subjects were asked to search for an odd target among the different numbers of distracters. Faces of the subjects’ own species, the backs of the head of the subjects’ own species, faces of the subjects’ closely related species or race, and faces of species that are clearly different from the subjects’ own species were used as the target. Both the macaques and humans detected a face of their own species more efficiently than a face from a clearly different species. Similar efficient detections were confirmed for the faces of the subjects’ closely related species or race. These results suggest that conspecific faces and faces that share morphological similarity with conspecific faces can be detected efficiently among non-face objects by both humans and Japanese macaques. In another experiment, facial recognition efficiency was observed when the subjects searched for own-species faces that had lower-spatial-frequency components compared to faces with higher-spatial-frequency components. It seems reasonable that the ability to search efficiently for faces by using holistic face processing is derived from fundamental social cognition abilities that are broadly shared among species.     

Parasitic egg rejection decisions of chalk-browed mockingbirds <Emphasis Type="Italic">Mimus saturninus</Emphasis> are independent of clutch composition

Obligate avian brood parasites lay their eggs in nests of other host species, which assume all the costs of parental care for the foreign eggs and chicks. The most common defensive response to parasitism is the rejection of foreign eggs by hosts. Different cognitive mechanisms and decision-making rules may guide both egg recognition and rejection behaviors. Classical optimization models generally assume that decisions are based on the absolute properties of the options (i.e., absolute valuation). Increasing evidence shows instead that hosts’ rejection decisions also depend on the context in which options are presented (i.e., context-dependent valuation). Here we study whether the chalk-browed mockingbird’s (Mimus saturninus) rejection of parasitic shiny cowbird (Molothrus bonariensis) eggs is a fixed behavior or varies with the context of the clutch. We tested three possible context-dependent mechanisms: (1) range effect, (2) habituation to variation, and (3) sensitization to variation. We found that mockingbird rejection of parasitic eggs does not change according to the characteristics of the other eggs in the nest. Thus, rejection decisions may exclusively depend on the objective characteristics of the eggs, meaning that the threshold of acceptance or rejection of a foreign egg is context-independent in this system.     

Anuran predators overcome visual illusion: dazzle coloration does not protect moving prey

Predators everywhere impose strong selection pressures on the morphology and behavior of their prey, but the resulting antipredator adaptations vary greatly among species. Studies of adaptive coloration in prey species have generally focused on cryptic or aposematic prey, with little consideration of color patterns in palatable mobile prey. Complex color patterns have been proposed to decrease the ability of visual predators to capture moving prey (motion dazzle effect). Most support for this hypothesis, however, comes from experiments with human subjects and simulated prey. We tested the motion dazzle effect using, for the first time, natural predators (cane toads, Rhinella marina) and live prey (house crickets, Acheta domesticus) with altered color patterns. We found no support for the motion dazzle effect as striped crickets did not fare better than solid colored ones. Crickets that spent more time moving, however, were more likely to be eaten. Our results suggest that motion specialized visual predators such as toads overcome the motion dazzle effect and impose stronger selection pressure on prey behavior than on coloration. These findings emphasize the importance of sensory specializations of predators in mediating antipredator strategies.     

The effect of experience and of dots’ density and duration on the detection of coherent motion in dogs

Knowledge about the mechanisms underlying canine vision is far from being exhaustive, especially that concerning post-retinal elaboration. One aspect that has received little attention is motion perception, and in spite of the common belief that dogs are extremely apt at detecting moving stimuli, there is no scientific support for such an assumption. In fact, we recently showed that dogs have higher thresholds than humans for coherent motion detection (Kanizsar et al. in Sci Rep UK 7:11259, 2017). This term refers to the ability of the visual system to perceive several units moving in the same direction, as one coherently moving global unit. Coherent motion perception is commonly investigated using random dot displays, containing variable proportions of coherently moving dots. Here, we investigated the relative contribution of local and global integration mechanisms for coherent motion perception, and changes in detection thresholds as a result of repeated exposure to the experimental stimuli. Dogs who had been involved in the previous study were given a conditioned discrimination task, in which we systematically manipulated dot density and duration and, eventually, re-assessed our subjects’ threshold after extensive exposure to the stimuli. Decreasing dot duration impacted on dogs’ accuracy in detecting coherent motion only at very low duration values, revealing the efficacy of local integration mechanisms. Density impacted on dogs’ accuracy in a linear fashion, indicating less efficient global integration. There was limited evidence of improvement in the re-assessment but, with an average threshold at re-assessment of 29%, dogs’ ability to detect coherent motion remains much poorer than that of humans.