Weak empirical support to say that problems with punishment (increases in escape & avoidance responses, punishment‐induced aggression, countercontrol, etc) are necessarily ubiquitous, long‐lasting, or specific to punishment

Punishment and its putative fallout: A reappraisal. Rafaela M. Fontes  Timothy A. Shahan. Journal of the Experimental Analysis of Behavio, December 6 2020. https://doi.org/10.1002/jeab.653

Abstract: In his book Coercion and Its Fallout Murray Sidman argued against the use of punishment based on concerns about its shortcomings and side effects. Among his concerns were the temporary nature of response suppression produced by punishment, the dangers of conditioned punishment, increases in escape and avoidance responses, punishment‐induced aggression, and the development of countercontrol. This paper revisits Sidman's arguments about these putative shortcomings and side effects by examining the available data. Although Sidman's concerns are reasonable and should be considered when using any form of behavioral control, there appears to be a lack of strong empirical support for the notion that these potential problems with punishment are necessarily ubiquitous, long‐lasting, or specific to punishment. We describe the need for additional research on punishment in general, and especially on its putative shortcomings and side effects. We also suggest the need for more effective formal theories of punishment that provide a principled account of how, why, and when lasting effects of punishment and its potential side effects might be expected to occur or not. In addition to being necessary for a complete account of behavior, such data and theories might contribute to improved interventions for problems of human concern.

Conclusion and Future Directions

Sidman's opposition to the use of aversive control, and more specifically to the use of punishment, was clear in his writings (e.g., Sidman, 1993, 2000, 2011). Although his concerns are reasonable and highlight important aspects to be considered when using any form of behavior control, the literature reviewed above suggests a lack of strong empirical support for the notion that these shortcomings and side effects are ubiquitous, long‐lasting, or specific to punishment. The transitory nature of response suppression produced by punishment does not appear to be an inherent issue with punishment and depends on many aspects of the environment and the contingency. In addition, although stimuli associated with unconditioned punishers can indeed become punishers themselves, such effects are not indiscriminately generalized to other stimuli present and do not necessarily persist once the contingency is suspended. Similarly, increases in escape and avoidance can be observed during punishment, but the occurrence of such responses is not necessary for punishment to suppress responding. Increases in aggressive behavior in the presence of aversive stimulation have also been shown to be a reliable effect; however, it is not necessarily or exclusively a result of punishment procedures. As with conditioned punishment effects, the occurrence of punishment‐induced aggression seems to be impacted by the organism's control of the punishment delivery. Lastly, although anecdotal examples of countercontrol have been described in the literature, countercontrol has not been empirically investigated and it remains unclear when or how such behavioral strategies might develop.

The lack of undesirable side effects associated with the use of punishment has also been noted in the applied literature (e.g., Brantner & Doherty, 1983; Harris, 1985; Johnston, 1972; van Oorsouw et al., 2008). Indeed, the use of punishment‐based interventions typically has been related to increases in positive behavior (e.g., Bostow & Bailey, 1969; Firestone, 1976; Risley, 1968; van Oorsouw et al., 2008). For example, Matson and Taras (1989) reviewed 382 applied studies employing different punishment procedures during interventions with individuals with developmental disabilities and concluded that the results reviewed did not provide evidence supporting the occurrence of undesirable side effects. Instead, the majority (93%) reported positive side effects during punishment interventions, such as increases in social behavior and responsiveness to the environment. Furthermore, the severity of the undesirable side effects, to the extent that they occur, was considered less harmful than the target behavior to be treated by punishment (Matson & Taras, 1989).

Given the considerations above, one wonders if opposition to the use of punishment might reflect a more general cultural tendency to regard its use as inherently bad. Such a view of punishment could be one of the reasons for the apparent decline in punishment research over the years (e.g., Bland et al., 2018; Johnston, 1991). Thus, the first step to renew the interest in punishment as a scientific topic is to acknowledge that aversiveness is not intrinsic to punishment but instead is contextually dependent (Leitenberg, 1965b; Perone, 2003). As noted by Perone (2003), the distinction between positive reinforcement and aversive control can be a matter of perspective, and every situation can be interpreted in terms of positive reinforcement or aversive control. As Sidman (1989/2000) noted, the use of deprivation to increase the efficacy of positive reinforcers might also be considered coercive. Thus, such concerns should not be taken as a reason to avoid seeking a better understanding of punishment (Vollmer, 2002).

Regardless of how one feels about Sidman's (1993, 2000, 2011) and others’ (e.g., Skinner, 1953, 1974) view of punishment, punishment‐based procedures are effective in reducing the behavior of several species, in both basic and applied settings (see Lerman & Vorndran, 2002 for a review). Indeed, punishment is a valuable method in the treatment of problem behavior, and is commonly used in such settings (e.g., Hagopian et al., 1998; Hanley et al., 2005; Lerman & Vorndran, 2002; Lydon et al., 2015; Matson & Taras, 1989; Risley, 1968; Thompson et al., 1999). However, much remains unknown about punishment and its potential side effects. These empirical and theoretical gaps emphasize the need for more research on punishment (e.g., Horner, 2002; Johnston, 1991; Todorov, 2001, 2011). The potential benefits of an increased understanding of punishment and its potential side effects could be manifold.

First, an improved understanding of punishment and its putative side effects could help shine an empirical light on preconceptions about the “dangerousness” of punishment. As noted above, there is a lack of strong empirical support for many of the putative shortcomings and side effects of punishment. In cases where those side effects do occur, many questions remain unanswered. For example, it is unclear under what circumstances punishment generalizes to other stimuli present during its presentation and if punishment effects generalize with unconditioned punishers besides shock. Much also remains unknown about the interactions between punishment and reinforcement. Better understanding such interactions could improve our understanding of decision‐making processes more generally by providing information about how organisms make trade‐offs between different types of consequences. Understanding such trade‐offs could provide important information about potential side effects of punishment. As one example, it is unknown if the availability of other sources of positive or negative reinforcement impacts the frequency of punishment‐induced aggression. Lastly, the complete lack of research on countercontrol makes clear the need for additional research on this potential side effect of punishment before it is considered in arguments against the use of punishment.

Second, additional research on punishment could contribute to the development of a well‐grounded quantitative theory of punishment. As discussed above, both the competitive‐suppression and direct‐suppression models have failed to adequately account for punishment data. Furthermore, to the extent that punishment side effects do occur, a good quantitative theory of punishment should provide a principled account of how, why, and when they occur. As just one example, response recovery is a robust and reliable phenomenon that needs to be accounted for by a quantitative model of punishment. If habituation indeed plays a role in response recovery during punishment, a theory of punishment will need to incorporate a formal account of habituation in order to predict the conditions under which recovery should be expected to occur.

Furthermore, a science of behavior cannot be complete without understanding how aversive consequences contribute to behavior control (e.g., Critchfield & Rasmussen, 2007; Johnston, 1991; Magoon & Critchfield, 2008; Vollmer, 2002). Punishment is a biological, behavior‐regulation mechanism critical for learning to stop engaging in maladaptive behavior (e.g., Todorov, 2011; Vollmer, 2002). Regardless of whether or not one believes that punishment should ever be a part of explicitly arranged contingencies, it will always be a part of natural ones. Thus, it is critical that punishment be effectively integrated into more general formal theories of behavior. But for that to happen, the amount of rigorous data related to punishment and its potential side effects needs to increase substantially. Not only would such data and theories be valuable in their own right, but they could also meaningfully improve applications to problems of human concern.

Finally, our call for increased empirical and theoretical work on punishment should not be misconstrued as a disregard for concerns about the use of punishment on ethical and humanitarian grounds. Nor should this call for additional research be mistaken as an argument for more widespread use of punishment‐based practices. Instead, our goal in highlighting empirical and theoretical gaps in the literature is to emphasize the need for a more complete understanding of punishment and its putative pitfalls before adopting or abandoning its use.

Humans tend to share food more generously than money and other objects: Preliminary evidence

Humans tend to share food more generously than money and other objects: Preliminary evidence. Agnieszka Sorokowska  Michalina Marczak  Michał Misiak  Anna Oleszkiewicz  Agnieszka Niemczyk  Monika Wróbel  Piotr Sorokowski. European Journal of Social Psychology, February 5 2021. https://doi.org/10.1002/ejsp.2747

Abstract: Food sharing is an especially important component of human cooperation, trust and altruism, and certain characteristics of food as compared to other objects may increase the likelihood of food transfers to other individuals. Consequently, people should exhibit higher generosity when sharing food than when sharing other goods (like money or inedible items). We tested this prediction in a series of natural experiments. In Study 1, we found that people (N = 114) were more likely to buy a bread‐roll for a confederate dressed up as a poor‐looking person than to give money for a bread‐roll or money to this person. In Study 2, 239 participants were more likely to donate food than non‐food items such as hygienic products or school accessories to a social welfare center. Finally, in Study 3, 226 subjects could share perishable, edible items (apples), coupons for apples or inedible items (pens) with fellow students, and there were no significant differences in generosity between these conditions. Overall, our results suggest that humans might exhibit a food sharing preference in certain conditions, especially when they share objects that belong to them and when they have a choice between sharing food‐ and non‐food items. However, further studies are necessary to confirm this notion, explore the characteristics of food that make sharing it particularly probable and to understand potential mechanisms underlying this tendency.

What makes It Difficult to keep an Intimate Relationship: Clinginess was reported as a more common source of relationship strain by women, bad sex was reported as a more common source of relationship strain by men

What makes It Difficult to keep an Intimate Relationship: Evidence From Greece and China. Menelaos Apostolou and Yan Wang. Evolutionary Psychology, January-March 2021: 1–12. https://journals.sagepub.com/doi/10.1177/1474704920987807

h/t David Schmitt What makes It Difficult to keep an Intimate Relationship: Evidence From Greece and China..."Clinginess was reported as a more common source of relationship strain by women, while bad sex was reported as a more common source of relationship strain by men

Abstract: Keeping an intimate relationship is challenging, and there are many factors causing strain. In the current research, we employed a sample of 1,403 participants from China and Greece who were in an intimate relationship, and we classified 78 difficulties in keeping an intimate relationship in 13 factors. Among the most common ones were clinginess, long work hours, and lack of personal time and space. Clinginess was reported as a more common source of relationship strain by women, while bad sex was reported as a more common source of relationship strain by men. Fading away enthusiasm, bad sex, infidelity and children were reported as more important by older participants, while lack of personal time and space, and character issues were reported as more important by younger participants. The factor structure was similar in the Greek and in the Chinese cultural contexts, but there were also differences. In addition, there were significant interactions between the sample and the sex. For instance, for the non-monogamous factor, men gave higher scores than women in both samples, but the difference was much more pronounced in the Greek sample.

Keywords: singlehood, keeping an intimate relationship, mismatch problem, mating

Discussion

Our analysis indicated that there were at least 13 factors that caused strain in keeping an intimate relationship. Among the highest rated ones were clinginess, long work hours, and lack of personal time and space. Women rated clinginess higher than men, while men rated bad sex higher than women. Older participants rated fading away enthusiasm, bad sex, infidelity and children higher, and lack of personal time and space and character issues lower than younger participants. Married people tended to give higher scores to several factors, such as fading away enthusiasm, than people in a relationship. The factor structure was similar in the Greek and in the Chinese cultural contexts, but there were also differences. For instance, the “Character issues” factor was rated higher in the Greek sample, while lack of effort was rated higher in the Chinese sample. There were also significant interactions between the sample and the sex. For instance, for the non-monogamous factor, men gave higher scores than women in both samples, but the difference was much more pronounced in the Greek sample.

Our study was designed with the purpose of identifying the most common sources of relationship strain among people who were actually in a relationship. For a factor to be rated highly, it had to be both frequent and strenuous. If a factor was frequent, but caused little strain, participants would probably tend to disagree that it caused them difficulties in keeping their relationship. Similarly, if a factor was a source of considerable strain, but it was rare, most participants would disagree that it caused them strain to their relationship. Nevertheless, if a factor was both frequent and strenuous, many participants would agree that it caused them strain to their relationship. In effect, at the top of our hierarchy were factors that were both common and strenuous.

Our findings indicate that there are no factors which cause difficulties to most people in keeping an intimate relationship, but most people are affected by one or more. More specifically, we can see that all the factors had a mean score below the middle of the scale, and frequencies close to 20%. However, more than 65% of the participants indicated that at least one factor caused them difficulties, and more than one in five indicated that four or more factors caused them difficulties. We also need to say that our data constitute a snapshot of the difficulties that people faced at the time of the study. Accordingly, although about one in three participants indicated that they did not face any of the difficulties examined here, they may had done so in the past, or may do so in the future.

In our theoretical framework, one main source of relationship strain is the adoption of a non-monogamous mating strategy. As indicated by the “Infidelity” factor, the adoption of such a strategy by one partner, if detected, is likely to trigger negative feelings to the other, which would make the continuation of the relationship difficult. As indicated by the “Not monogamous” factor, the adoption of such a strategy makes also being with one partner difficult. These factors however, were located at the bottom of the hierarchy, suggesting that they were not the most common sources of relationship strain. One reason is that, non-monogamous mating strategies are adopted only by a small proportion of the population. Another reason is that, people, when act on such strategies, take precautions not to be detected (see also Buss, 2000), and if they succeed in doing so, their mating strategy may not cause strain to the relationship. In effect, although infidelity is potentially a source of very strong relationship strain, it is relatively rare, and when it occurs, it is likely to go undetected, which could explain why many participants did not indicate that it caused them difficulty in keeping their intimate relationship.

On the other hand, the partner-monitoring mechanisms constitute a much more common source of relationship strain. In particular, the “Clinginess” was reported to be the most common source of difficulties. The “Character issues,” part of which was jealousy, was also reported as a common source of relationship strain. The “Lack of personal time and space” is the consequence of the functioning of the partner-monitoring mechanisms, and was reported as the third more common difficulty. These findings are expected, because these mechanisms have a preemptive function; that is, they protect people from having their partners to act on a non-monogamous mating strategy, and for doing so, they need to be always “on.” To put it differently, they could not have a preemptive function if they are triggered only when the partner is cheating.

Another reason that factors, such as the “Clinginess” and the “Lack of personal time and space,” top the hierarchy of difficulties is the mismatch problem. Mechanisms that give rise to clinginess have been optimized for a context where people were heavily dependent on their partners, so they had higher tolerance in being closely monitored. Similarly, the “Character issues,” the “Not making compromises,” and the “Violence and addictions” are also likely to reflect the mismatch problem, as traits, such as violent disposition and inflexibility, were more likely to be tolerated in the ancestral than in the modern context. Furthermore, since partners are relatively independent from each other, the contemporary environment requires more mating effort in order to keep an intimate relationship. Yet, mechanisms involved in regulating mating effort have evolved in the ancestral context where less of this effort was required, which could explain, why the “Lack of effort” was a common difficulty in keeping an intimate relationship in the contemporary context.

Long work hours was the most common relationship-resources depleting factor, ranking second in the hierarchy of difficulties. This finding probably reflects the reality that job demands in contemporary societies are high, requiring many hours to be devoted to work, which are deducted from the relationship. Children constitute another relationship-resources depleting factor, which was located near the bottom of the hierarchy. This rank is probably due to the fact that our sample was relatively young, so most participants did not have children. We would expect financial difficulties to arise as a separate factor, which was not the case. Similarly, Apostolou and Wang (2020) did not find financial difficulties as a separate factor causing difficulties in keeping an intimate relationship. One possibility is that participants considered financial difficulties to arise from other factors, such as having children, as Apostolou and Wang (2020) have found, or from the character of the partner, as indicated in the current study.

The “Fading away enthusiasm” and the “Bad sex” factors, have most probably multiple explanations. In particular, the adoption of a non-monogamous mating strategy may involve reduction in enthusiasm and sexual satisfaction with the current partner that would motivate people to seek other partners. Furthermore, in the ancestral context where people were heavily dependent on their partners, the levels of enthusiasm and sexual pleasure received from a long-term partner required for keeping an intimate relationship, were most probably lower than in the modern context where people are less dependent on their partners. Thus, mechanisms responsible for generating enthusiasm and for regulating sexual behavior, may not work optimally in the modern environment. In addition, relationship-resources depleting factors, may also be at play here. For instance, working long hours may lead to physical exhaustion, which in turn, would negatively affect the quality of sex.

Our original prediction that men would face more difficulties in keeping their relationship was partially supported. In particular, for the pooled sample, men scored higher than women, but the result was significant only if Bonferroni correction was not applied. On the other hand, our prediction that women would face more difficulties in keeping a relationship arising from the infidelities of their partners was not supported. One possibility is that men are more likely to adopt a cheating mating strategy than women, but they are more efficient in hiding it. Future research could enable a better understanding of the difficulties that infidelity causes in keeping an intimate relationship.

Age was also significant for several factors. The largest effects were for the “Children” and the “Bad sex” factors, with older participants giving higher scores than younger ones. With respect to the former, this effect is predominantly explained by older participants being more likely to have children than younger ones. With respect to the latter, quality and quantity of sexual contact may deteriorate as people spend more time in their relationship, with age acting as a proxy of time spent in it. Another reason is that libido declines as people get older (Travison et al., 2006), which has a negative impact on the quality and quantity of sex they have with their partners.

We also found that married participants tended to give higher scores to a number of factors than people in a relationship. The most likely explanation is that, when they first enter in a relationship, people are overwhelmed by emotions, such as romantic love, which lead them to overlook or tolerate factors that negatively affect the relationship. As years go by, these emotions reside and these factors become more taxing for the relationship. Thus, the more time people spend in a relationship, the higher the strain arising from different factors becomes. Most likely, participants who were married have spent more time in a relationship than participants who were not married, so marital status acted as a proxy of time being in a relationship. Future studies could disentangle marital status from time being in a relationship effects by measuring both variables.

Consistent with our original prediction, the factor structure was similar in the Chinese and in the Greek cultural contexts. There were differences however, between the two cultural settings. In particular, Chinese participants reported the lack of mating effort to be a more common source of relationship strain, than Greek participants. One possible reason is a wider use of dating applications among young people in China, which could lead them to believe that they can easily substitute their current partner, so they do not spend considerable effort in keeping their relationship (Ding, 2020; Ya & Zhang, 2020). In addition, Greek participants indicated that character issues were a more common source of relationship strain than Chinese participants have indicated. One explanation is that, the Greek culture is more individualistic than the Chinese one (in Hofstede’s index for individualism Greece scored 35 and China 20 see https://clearlycultural.com/geert-hofstede-cultural-dimensions/individualism), so traits, such as being selfish, are more pronounced in the former than in the latter.

Furthermore, there were significant interactions between the sample and the sex. More specifically, the sex difference in the “Not monogamous” factor was less pronounced in the Chinese sample. One likely explanation is that, in the Chinese cultural context, men outnumber women (Liang & Ni, 2018), which turns finding a partner more difficult for them. Such a difficulty may suppress an innate desire for variety in partners, something which is not the case in the Greek context where the sex ratio is balanced. The difference in the sex ratio may also explain why in the pooled sample the sex-difference for the “Not monogamous” factor did not pass the Bonferroni-adjusted significance level. There was a higher number of Chinese than Greek male participants, and if the sex ratio imbalance influenced the former in suppressing their desire for partner variety, then the pooled sex difference would be relatively small. In addition, the sex ratio effect, possibly explains the significant interaction between the sex and the sample for the “Not making compromises” factor. In particular, by being in scarce supply, women in China can be selective, and can afford to make fewer compromises than women in Greece.

One limitation of the present work is that it is far from sufficient for understanding the difficulties that people face in keeping an intimate relationship, and it should thus, be considered as one of the first steps toward this direction. In the same vein, given the complexity of the phenomenon, there are probably more difficulties that people face in keeping an intimate relationship that have been accounted by the present study. For instance, men are expected to earn more than women (Hogue et al., 2010); thus, a situation where a husband earning less than the wife may generate considerable strain to the relationship. Future research needs to identify and account for additional sources of relationship strain.

Moving on, we paid particular attention in developing a theoretical framework that would account for the observed difficulties. Still, this framework may need further development, which could involve incorporating arguments from other schools of thought. Further limitations include that our findings were based on self-report data, and participants may not have had a good understanding or may have been unwilling to be honest about what caused them difficulties in keeping their relationship. In addition, we employed non-probability samples, so our results may not readily generalize to the population. That is, it is possible that the recruited individuals were different from those who opted not to participate in ways that affect the generalizability of the results. Moreover, for the Greek-speaking respondents, the survey link was also forwarded by email to students and colleagues, so there is the possibility that some of those who answered the survey were in a relationship with each other, and thus, their answers were to some degree correlated. We do not think that this limitation had a considerable effect on our findings, because the bulk of the participants were recruited through promoting the link in social media.

Furthermore, our theoretical framework predicted cross-cultural consistency but also variation in the causes of relationship strain. Evidence from more than two different cultures is required for adequately testing these predictions, and future research needs to extend our work by replicating it in different cultural settings. In addition, the current study did not examine how likely each of the identified difficulties would be in leading to the termination of the relationship. Future studies could address this limitation by asking how each of the identified difficulties have actually caused people to terminate an intimate relationship.

In conclusion, we identified thirteen factors causing relationship strain. We have also found that these factors were similar in the Chinese and in the Greek cultural contexts, but there were important differences. Considerable more research is required, however, in order to understand this fascinating and complex phenomenon.

Do Lower Minimum Wages for Young Workers Raise their Employment? Evidence from a Danish Discontinuity

Do Lower Minimum Wages for Young Workers Raise their Employment? Evidence from a Danish Discontinuity. Claus Thustrup Kreiner, Daniel Reck, Peer Ebbesen Skov. Centre for Economic Policy Research, June 4, 2017. https://cepr.org/sites/default/files/3564_KREINER%20-%20Do%20Lower%20Minimum%20Wages%20for%20Young%20Workers%20Raise%20their%20Employment_0.pdf

Abstract: This paper estimates the long-run impact of youth minimum wages on youth employment by exploiting a large discontinuity in Danish minimum wage rules at age 18 and using monthly payroll records for the Danish population. We show theoretically how the discontinuity in the minimum wage may be exploited to estimate the casual eect of a change in the minimum wage of youth on their employment. On average, the hourly wage rate jumps up by 40 percent when individuals turn eighteen years old. Employment (extensive margin) falls by 33 percent and total labor input (extensive and intensive margin) decreases by around 45 percent, leaving the aggregate wage payment nearly unchanged. Data on flows into and out of employment show that the drop in employment is driven almost entirely by job loss when individuals turn 18 years old. We estimate that the relevant elasticity for evaluating the eect on youth employment of changes in their minimum wage is about -0.8.

Keywords: Minimum wage policy, employment, regression discontinuity

We observed 584 instances of sociosexual behaviour in chimpanzees in 3 years; all ages and sexes engaged in sociosexual behaviour; most sociosexual behaviour was between adult males

Sociosexual behaviour in wild chimpanzees occurs in variable contexts and is frequent between same-sex partners. Aaron A. Sandel & Rachna B. Reddy. Behaviour, Feb 2 2021, https://doi.org/10.1163/1568539X-bja10062

Rolf Degen's take: Sociosexual behavior, including that between same-sex pairs, is a standard component of chimpanzee behavior

Abstract: Many animals engage in sociosexual behaviour, including that between same-sex pairs. Bonobos (Pan paniscus) are famous for their sociosexual behaviour, but chimpanzees (Pan troglodytes) apparently do not engage in sociosexual behaviour frequently. However, sociosexual behaviour in chimpanzees may have been overlooked. We observed 584 instances of sociosexual behaviour in chimpanzees at Ngogo, Kibale National Park, Uganda during three years of study. All ages and sexes engaged in sociosexual behaviour, which included mounting, touching of genitals, and pressing genitals together. Most sociosexual behaviour was between adult males. Sociosexual behaviour was often during tense contexts, such as subgroup reunions and during territorial behaviour. Among males, grooming and dominance rank relationships do not explain patterns of sociosexual behaviour. Although sociosexual behaviour may be less frequent in chimpanzees than in bonobos, and bonobos remain distinct in their genito-genital rubbing, our findings suggest that sociosexual behaviour is a regular part of chimpanzee behaviour.

Keywords: genital contact; Pan troglodytes; mounting; same-sex sexual behaviour

Lay comments: Same-Sex Sexual Behavior in Chimpanzees Challenge Our Gendered Biases About Evolution. Michelle Rodrigues, 2021. https://thisviewoflife.com/same-sex-sexual-behavior-in-chimpanzees-challenge-our-gendered-biases-about-evolution/

4. Discussion Sociosexual behaviour, including same-sex sexual behaviour, occurred in every sex- and age-class combination among chimpanzees at Ngogo. The most common type of sociosexual behaviour was mounting. Chimpanzees would also reach their hand to touch the rump or genitals of others and on rare occasions touch rumps or engage in genito-genital touching. Sociosexual behaviour occurred in multiple contexts. In nearly all cases for which we recorded the context, the context represented cases of tension, often due to aggression or the threat of aggression, including during food sharing, upon hearing neighbouring groups of chimpanzees, or prior to or after joining another subgroup within the community (Table 2). Sociosexual behaviour was variable among the Ngogo chimpanzees. It appeared to be most common between adult males. This may be due to the cooperative nature of male chimpanzees, and the tension involved during certain activities, such as reunions that involve the reestablishment of dominance relationships. Adolescent and young adult male chimpanzees were the A.A. Sandel, R.B. Reddy / Behaviour (2021) 19 focus of our research, so they may be overrepresented in the sample. Indeed, we have considerably more observation time on them than any other agesex class. However we frequently observed sociosexual behaviour between adult male pairs that were not the focus of our research. Despite our focus on adolescent and adult males, we recorded individuals in all possible age-sex class pairings engage in sociosexual behaviour including between sexually mature adult females (Table 1). Nevertheless, given our sampling procedure, females and infants are likely underrepresented. In fact, we likely underestimated the frequency of sociosexual behaviour in general, as such behaviours often occurred quickly and during somewhat chaotic events, including during aggression or just prior to the chimpanzees running toward a neighbouring group of chimpanzees, making it difficult to record. Some individuals appeared to engage in sociosexual behaviour more than others. Several adult males accounted for a large proportion of sociosexual behaviours. One young adult male, somewhat low-ranking but rising in the male hierarchy (Evans), mounted others 30 times, and only twice was mounted by others. Another adult male, middle-aged and relatively lowranking (Mulligan) was mounted nine times, and never mounted others. In fact, these two males engaged in one of the instances of genito-genital rubbing (Video 1 at 10.6084/m9.figshare.13546526). One of these males, Mulligan, was also involved in an unusual case of mounting in which he presented his rump to another male, and while the other male (Dexter) mounted him, Mulligan crouched down on the ground in a posture resembling that of females during a copulation. Other males that were over-represented in our sample included high-ranking adult males. It is possible that status and personality play a role in the frequency of sociosexual behaviour. High-ranking males may encounter tense situations frequently — competing for mating opportunities, sharing meat, participating in border patrols — instigating sociosexual behaviour as well as other forms of relationship regulation, such as grooming. In addition, some males may be more ‘nervous’ in general, and thus seek out reassurance from others. With regard to the prevalence of sociosexual behaviour in chimpanzees, it is possible that it is more common at Ngogo than other chimpanzee sites. There are more males at Ngogo than any other community that has been studied. At Ngogo, chimpanzees, especially adult males, engage in frequent cooperative behaviour, group hunts, and border patrols (Mitani et al., 2000; Mitani & Watts, 2001; Watts & Mitani, 2001; Mitani, 2009b; Langergraber et al., 2017). Being surrounded on all sides by other chimpanzee communities, they regularly have intergroup encounters. As a result, there may be heightened need for regulating tension. However, we consider it unlikely that Ngogo stands out with regard to the nature and prevalence of sociosexual behaviour as similar behaviours have been described at multiple other sites (van Lawick-Goodall, 1968; Bygott, 1974; Nishida et al., 1999). For example, a study at Gombe found that 50% of all touching between male chimpanzees (N = 194 total touches) involved touching of genitals, and 70% of all touching between female chimpanzees (N = 56 total touches) involved touching genitals (Bygott, 1974). There also appeared to be variation among individuals in the frequency and patterning of sociosexual behaviour, including with some individuals being distinct in their sociosexual behaviour. Bygott (1974, p. 63) noted that “the adult male Faben often presented to other males, and when they held out a hand to him he would bounce his scrotum up and down against their hand. No other male was seen to do this.” Further research is required to test hypotheses for the function of sociosexual behaviour in wild chimpanzees. Our findings suggest that sociosexual behaviour is unlikely related to dominance given that combinations of all age and sex classes engaged in these behaviours. Importantly, in cases of mounting between males, the mounter was not higher ranking; if anything, the mounter tended to be lower ranking than the mountee, although mounters were also frequently higher ranking than the mountee (Figure 5). Sociosexual behaviour may relate to other behaviours, such as affiliative bonds, but grooming was not a strong predictor of sociosexual behaviour (Figure 4). Some pairs that groomed frequently also engaged in sociosexual behaviour more than did other pairs, but sociosexual behaviour also occurred between males who associated less frequently because they occupied different social neighbourhoods within the community. Thus, at least for males, sociosexual behaviour may be a way to reduce tension among pairs who meet infrequently. The function of sociosexual behaviour likely varies by age and sex. For example, we observed infant females rubbing their genitals on others, and this may have been for a pleasurable sensation alone (Vasey & Duckworth, 2006). Further study of sociosexual behaviour is required in chimpanzees, particularly focused on females, and how the function of sociosexual behaviour changes with development, which will in turn inform its possible functions. Although we focused on genital contact, much of the behaviour that we observed resembled what other researchers have A.A. Sandel, R.B. Reddy / Behaviour (2021) 21 considered ‘reassurance’ behaviour (Goodall, 1986; Nishida et al., 1999). Prior studies seem to have lumped sociosexual behaviour within reassurance behaviour, and indeed, they may serve the same function. Future studies should analyse sociosexual behaviour along with other forms of touch, including mouth-to-mouth, hand-to-mouth, hand-to-hand, hand-to-body, and embraces without genital contact. Given that much of sociosexual behaviour across mammals has been linked to cooperation and tension reduction in fission-fusion species, it is no surprise that chimpanzees do it. Indeed, this finding is not new. Some of the earliest studies of chimpanzees reported behaviours involving mounting and genital contact, both in captivity (Crawford, 1942) and the wild (Nishida, 1968; van Lawick-Goodall, 1968; Sugiyama, 1969). However, the ensuing decades have focused on such behaviours in bonobos, framing them as key for tolerance and female power (Hohmann & Fruth, 2000; Hohmann et al., 2009), and this seems to have downplayed its significance in chimpanzee life. For example, Hohmann et al. (2009) considered genital contact to be ‘habitual’ in bonobos, but not in other apes, and Grueter & Stoinski (2016) considered same-sex sexual behaviour “rare or absent among chimpanzees” in their study of such behaviours in wild gorillas. Similarly, sociosexual behaviour is considered “weak or infrequent” in East African chimpanzees (Pan troglodytes schweinfurthii) compared to hunting, which is “strong or highly frequent,” and infanticide, which is “moderate or frequent” (Gruber & Clay, 2016). In our study, sociosexual behaviour occurred considerably more frequently than did infanticides and was closer to the frequency of hunts, thus we would not consider it as “weak or infrequent”. Although we were not able to calculate a rate of sociosexual behaviour for most of our subjects, sociosexual behaviour was only one third as frequent as mating behaviour. And adolescent and young adult males tended to exhibit sociosexual behaviour approximately once every two months, which is likely an underestimate. It may have been that the study by Gruber and Clay (2016) considered a more limited array of behaviours as sociosexual, which could also account for its apparent absence between young chimpanzees compared to bonobos in an experimental feeding context (Woods & Hare, 2011). When analysing chimpanzee behaviour, scientists seem to classify mounts or genital contact within other functional behaviours, such as gestures or reassurance. We do not dispute that genital contact may serve conciliatory or communicative purposes in chimpanzees, but we also suggest that it deserves attention in studies investigating sociosexual behaviour explicitly. Doing so will allow proper comparisons to bonobos, and may elucidate the evolution and function of sociosexual behaviour in primates more generally. Although we found chimpanzees to engage in a range of sociosexual behaviours, bonobos remain distinct. Bonobos exhibit frequent genito-genital rubbing, especially between adult females (Hohmann & Fruth, 2000), whereas, we recorded only three instances of face-to-face, genito-genital rubbing in chimpanzees, and it was only observed between adult males. However, different species of primates manifest different forms of sociosexual behaviour, such as ‘ritualized’ touching of the penis in some baboons species (Smuts & Watanabe, 1990; Dal Pesco & Fischer, 2018). For chimpanzees, mounting and touching genitals may be their species-typical manifestation of sociosexual behaviour. That behaviours involving gential contact have not been conceptualized as ‘sociosexual’ in chimpanzees may also be due to cultural biases against homosexuality, as has been seen in the literature on other primates (Vasey, 1995). “Never, however, have we seen anything that could be regarded as homosexuality in chimpanzees,” Jane Goodall writes in her 1971 book, In the Shadow of Man. “Admittedly a male may mount another in moments of stress or excitement, clasping the other around the waist, and he may even make thrusting movements of the pelvis, but there is no intromission. It is true, also, that a male may try to calm himself or another male by reaching out to touch or pat the other’s genitals; while we still have much to learn about this type of behaviour, it certainly does not imply homosexuality. He only does this in moments of stress, and he will touch or pat a female on her genitals in exactly the same contexts” (Goodall, 2010, pp. 183–184). We agree that this does not indicate ‘homosexuality’ in the sense of a sexual orientation, but it does potentially represent sexual behaviour broadly defined, including that between members of the same sex. Our findings reveal that sociosexual behaviour is a standard component of chimpanzee behaviour. Although sociosexual behaviour is, no doubt, more salient and frequent in bonobos, especially with their characteristic side-toside genital rubbing, the range and type of sociosexual behaviour is similar in chimpanzees. Thus, there should not be such a distinction made between the two species. In addition, given the evidence of sociosexual behaviour in gorillas and a range of monkey species (e.g., Yamagiwa, 1987; Grueter & Stoinski, 2016), sociosexual behaviour is likely a common trait to haplorrhine primates. In some primate species, sociosexual behaviour has become key to negotiating relationships, as is the case in bonobos, some baboon A.A. Sandel, R.B. Reddy / Behaviour (2021) 23 species, and some populations of spider monkeys. Given its prevalence across taxa, sociosexual behaviour, including between members of the same sex, may be an important component of relationships that arose early on in primate evolution.

There was not a single childcare task that men liked more than women did; findings imply that aims of gender equity across the board may be difficult to achieve & may also work against partners’ individual preferences

Bleske-Rechek, A., & Gunseor, M. M. (2021). Gendered perspectives on sharing the load: Men’s and women’s attitudes toward family roles and household and childcare tasks. Evolutionary Behavioral Sciences, Feb 2021. https://doi.org/10.1037/ebs0000257

Abstract: In the United States, women continue to spend more time than men do on household labor and childcare (Parker & Wang, 2013). Although these gender disparities in time use are lamented in the media as inequitable (Miller, 2020; Rao, 2019), differences in men’s and women’s preferences may help explain the disparities. In the current study, emerging adults (N = 323) and middle-aged adults (N = 113) reported (a) the degree to which they like or dislike 58 different household tasks and 40 different childcare tasks; (b) how they would prefer to split up each task with a partner; and (c) their ideal prioritization of work and family. In both samples, male–female differences in enjoyment of household and childcare tasks paralleled male–female differences in task-split preferences. For example, men liked home maintenance and yard care more than women did, and, in turn, leaned more toward wanting primary responsibility for those tasks than women did. Although there were some household tasks that men liked much more than women did and there were some household tasks and childcare tasks that women liked much more than men did (e.g., decorating the home, shopping for the children), there was not a single childcare task that men liked more than women did. Our findings imply that aims of gender equity across the board may be difficult to achieve and may also work against partners’ individual preferences.

Men’s stress expression & their partner's perceived supportiveness are linked to positive effects for men’s well-being & that of the relationship; stress & adherence to masculine norms negatively affect men’s expression of stress

Kapsaridi, A., & Charvoz, L. (2021). Men’s stress expression and perception of partner’s support within the romantic relationships: A systematic review. Psychology of Men & Masculinities, Feb 2021. https://doi.org/10.1037/men0000276

Abstract: Although research on men’s stress expression, coping strategies, and attitudes toward support has been accumulated, there is a lack of evaluation of men’s stress expression and perception of their partners’ supportiveness within the context of romantic relationships. This review summarizes findings related to factors that influence men’s expression of stress and the ways in which they perceive the support provided by their romantic partners, as well as the resulting effects on men’s well-being and that of the relationship itself. We searched four electronic databases using terms related to stress expression and perceived supportiveness in couples. Findings meeting inclusion criteria were classified in two conceptual categories: (a) Men’s stress expression to their partner and (b) men’s perception of their partner’s support. Forty-four articles met inclusion criteria. Data were collected on 4,520 men from clinical/subclinical and healthy populations. Findings suggest that (a) men’s stress expression and perceived supportiveness from their partner are linked to positive effects for men’s well-being and that of the relationship; (b) stress and adherence to masculine norms negatively affect men’s expression of stress to their romantic partner; and (c) men’s perception of their romantic partner’s support is negatively affected by stress and positively linked to men’s stress expression. These results suggest that for men, stress expression and perceived supportiveness within the context of the romantic relationship parallel their general attitudes regarding self-disclosure and social support. The prescriptive role of masculine norms is highlighted as an important determinant of men’s behavior toward their romantic partner.

Individual variability in brain development from late childhood to young adulthood: There are sex differences in development changes; & found an association between an individual's brain size & rate of change

Individual variability in structural brain development from late childhood to young adulthood. Kathryn L Mills, Kimberly D Siegmund, Christian K Tamnes, Lia Ferschmann, Marieke G N Bos, Lara M Wierenga, Beatriz Luna, Megan L Herting. bioRxiv Feb 4 2021. https://doi.org/10.1101/2021.02.04.429671

Abstract: A fundamental task in neuroscience is to characterize the brain's developmental course. While replicable group-level models of structural brain development from childhood to adulthood have recently been identified, we have yet to quantify and understand individual differences in structural brain development. The present study examined individual variability and sex differences in changes in brain structure, as assessed by anatomical MRI, across ages 8.0-26.0 years in 269 participants (149 females) with three time points of data (807 scans), drawn from three longitudinal datasets collected in the Netherlands, Norway, and USA. We further investigated the relationship between overall brain size and developmental changes, as well as how females and males differed in change variability across development. There was considerable individual variability in the magnitude of changes observed for all included brain measures. However, distinct developmental patterns of change were observed for total brain and cortical gray matter, cortical thickness, and white matter surface area, with individuals demonstrating either stability or decreases in early adolescence, then almost universal decreases during mid-to-late adolescence, before returning to more variable patterns in early adulthood. White matter volume demonstrated a similar developmental pattern of variability, but with individuals shifting from increases to a majority stabilizing during mid-to-late adolescence. We observed sex differences in these patterns, and also an association between an individual's brain size and their overall rate of change. The present study provides new insight as to the amount of individual variance in changes in structural morphometrics from late childhood to early adulthood in order to obtain a more nuanced picture of brain development. The observed individual- and sex-differences in brain changes also highlight the importance of further studying individual variation in developmental patterns in healthy, at-risk, and clinical populations.

Long-term improvement in neighborhood economic level was associated with lower risk for excessive weight gain and excessive weight loss

Association of Long-Term Trajectories of Neighborhood Socioeconomic Status With Weight Change in Older Adults. Dong Zhang et al. JAMA Netw Open. 2021; 4(2):e2036809. doi:10.1001/jamanetworkopen.2020.36809

Key Points

Question  What is the association between neighborhood socioeconomic status (SES) change and weight change among older adults?

Findings  In this cohort study of 126 179 US adults, long-term improvement in neighborhood SES was associated with lower risk for excessive weight gain and excessive weight loss, while long-term neighborhood SES decline was associated with higher risks for these outcomes. There was a dose-dependent association, with larger changes in risk observed with larger neighborhood changes.

Meaning  This study found that sustained neighborhood changes were associated with significant differences in weight outcomes among older adults.

Abstract

Importance  Studying long-term changes in neighborhood socioeconomic status (SES) may help to better understand the associations between neighborhood exposure and weight outcomes and provide evidence supporting neighborhood interventions. Little previous research has been done to examine associations between neighborhood SES and weight loss, a risk factor associated with poor health outcomes in the older population.

Objective  To determine whether improvements in neighborhood SES are associated with reduced likelihoods of excessive weight gain and excessive weight loss and whether declines are associated with increased likelihoods of these weight outcomes.

Design, Study, and Participants  This cohort study was conducted using data from the National Institutes of Health-AARP (formerly known as the American Association of Retired Persons) Diet and Health study (1995-2006). The analysis included a cohort of 126 179 adults (aged 50-71 years) whose neighborhoods at baseline (1995-1996) were the same as at follow-up (2004-2006). All analyses were performed from December 2018 through December 2020.

Exposures  Living in a neighborhood that experienced 1 of 8 neighborhood SES trajectories defined based on a national neighborhood SES index created using data from the US Census and American Community Survey. The 8 trajectory groups, in which high, or H, indicated rankings at or above the sample median of a specific year and low, or L, indicated rankings below the median, were HHH (ie, high in 1990 to high in 2000 to high in 2010), or stable high; HLL, or early decline; HHL, or late decline; HLH, or transient decline; LLL, or stable low; LHH, or early improvement; LLH, or late improvement; and LHL, or transient improvement.

Main Outcomes and Measures  Excessive weight gain and loss were defined as gaining or losing 10% or more of baseline weight.

Results  Among 126 179 adults, 76 225 (60.4%) were men and the mean (SD) age was 62.1 (5.3) years. Improvements in neighborhood SES were associated with lower likelihoods of excessive weight gain and weight loss over follow-up, while declines in neighborhood SES were associated with higher likelihoods of excessive weight gain and weight loss. Compared with the stable low group, the risk was significantly reduced for excessive weight gain in the early improvement group (odds ratio [OR], 0.87; 95% CI, 0.79-0.95) and for excessive weight loss in the late improvement group (OR, 0.89; 95% CI, 0.80-1.00). Compared with the stable high group, the risk of excessive weight gain was significantly increased for the early decline group (OR, 1.19; 95% CI, 1.08-1.31) and late decline group (OR, 1.13; 95% CI, 1.04-1.24) and for excessive weight loss in the early decline group (OR, 1.15; 95% CI, 1.02-1.28). The increases in likelihood were greater when the improvement or decline in neighborhood SES occurred early in the study period (ie, 1990-2000) and was substantiated throughout the follow-up (ie, the early decline and early improvement groups). Overall, we found a linear association between changes in neighborhood SES and weight outcomes, in which every 5 percentile decline in neighborhood SES was associated with a 1.2% to 2.4% increase in the risk of excessive weight gain or loss (excessive weight gain: OR, 1.01; 95% CI, 1.00-1.02 for women; OR, 1.02; 95% CI, 1.01-1.03 for men; excessive weight loss: OR, 1.02; 95% CI, 1.01-1.03 for women; OR, 1.02; 95% CI, 1.01-1.03 for men; P for- trend < .0001).

Conclusions and Relevance  These findings suggest that changing neighborhood environment was associated with changes in weight status in older adults.

Discussion

In this large cohort study of older US adults, we found that, consistent with our hypothesis, participants in neighborhoods with declines in SES were at higher risk of excessive weight gain and loss, while those in neighborhoods with improvements in SES were at lower risk of these outcomes. Moreover, our results showed dose-dependent associations, in which larger improvements and declines were associated with larger differences in risk of adverse weight outcomes.

Several previous investigations on changes in neighborhood SES and weight outcomes reported findings similar to ours. In the Dallas Heart Study (DHS), a population-based cohort study in Dallas County, Texas, Powell-Wiley et al⁶ reported that moving to more disadvantaged neighborhoods was associated with larger weight gain over 7 years of follow up compared with moving to similar or more advantaged neighborhoods. In another DHS study, Leonard et al⁴ characterized neighborhood SES using property appraisal values and found that a 1-SD improvement in neighborhood conditions was associated with 0.7 kg less weight gain, and the association appeared stronger among nonmovers than movers. Additionally, a longitudinal analysis⁵ among California mothers found that moving to a census tract with a lower poverty level was associated with a 50% reduction in the odds of obesity. Overall, these findings and ours suggest that improvements in neighborhood conditions were associated with lower obesity, while residents in deteriorating neighborhoods may be at higher risk for obesity and related chronic conditions.

However, not all study results were consistent with ours. An early investigation in the Multi-Ethnic Study of Atherosclerosis⁷ used latent growth curve models to estimate six 20-year trajectory groups (1980-1999) of neighborhood poverty patterns and found that the trajectory showing substantial reductions in poverty (4.1% of study population) was not associated with BMI. In another study, Kimbro et al⁸ examined the likelihood of obesity in association with within-individual changes in neighborhood conditions and had null findings. Although it is unclear what specific factors may lead to inconsistent results among these studies, all studies, including ours, differed in a number of ways, including population sociodemographic characteristics, geographic regions, measures of neighborhood SES and weight outcomes used, and statistical model characteristics, including controlling of confounders. We need future studies, including original investigations, meta-analyses, and systematic reviews, to clarify the association between changes in neighborhood SES and weight outcomes, identify population and contextual factors that may modulate the associations, and examine methodological issues that may be associated with changes in the results.

A main distinction between our study and the earlier studies was that we treated weight gain and weight loss as separate outcomes. Weight loss is prevalent among older populations; it has been estimated that 15% to 20% of adults aged 65 years or older experienced a 5% or greater reduction in body weight over a relatively short period of time (ie, 6 months to 1 year), often without an intention to lose weight.¹³ Unintentional weight loss has been associated with social isolation, poor nutrition, and chronic diseases, such as cancer, gastrointestinal problems, and mental disorders.¹³ The high prevalence and distinct underlying mechanisms of unintentional weight loss suggest that it should be treated as a unique weight outcome in older populations. Neighborhood environment has been associated with risks for cancer and mental disorders^25,26 and is a critical factor associated with shaping social interactions, diet, and physical activity behaviors.²⁷ Indeed, we found that neighborhood declines were associated with a higher risk for excessive weight loss. However, our observational study was not designed to establish causality, and we did not examine the underlying mechanisms of the observed associations. Future studies should focus on pinpointing the specific pathways through which neighborhood environment may affect weight loss. It has been estimated that weight loss was associated with a 22% to 39% increase in mortality risk in healthy older adults and those with chronic conditions.¹² Thus, our study results suggest that clinicians and public health officials should pay close attention to weight loss among older adults who live in a neighborhood with declining SES. Moreover, as most of the current research efforts, to our knowledge, focus on obesity, weight loss remains an understudied area and more research is needed to identify modifiable risk factors at the individual and neighborhood levels to inform clinical practices and public health interventions.

Our study measured neighborhood SES at 3 time points, which allowed us to distinguish among changes that occurred early, late, or transiently during the 20-year study period. In most cases, we found that improvements or declines that occurred early tended to be associated with larger increases in risk, suggesting that there may be a lag period for the association of weight with changes in neighborhood SES. Furthermore, the results also indicated that it may require sustained neighborhood changes for a significant association with changes in weight distribution among residents to appear, a potentially important consideration when designing programs aimed at improving neighborhood conditions to promote healthy weight status.

Our study has important strengths, including a large sample size, geographically diverse neighborhoods, and a long follow-up period. Neighborhoods tend to be stable over time. Therefore, it requires a large and diverse population to capture the small fraction of neighborhoods with substantial changes. Another strength of this study is its use of national rankings to assess neighborhood SES, instead of relying on sample-specific measures. This strategy may have reduced the impact of events and trends that are highly specific to the study population. For example, a study that included neighborhoods that, as a whole, experienced deteriorating conditions would characterize a stable neighborhood in this study as an improved neighborhood; the same neighborhood would be characterized as a declined neighborhood in a study that included neighborhoods with largely upward changes in SES. As a result, it may be difficult to generalize the findings from 1 study to others or to the entire country, and the use of national rankings in our current study was associated with reductions in this problem.

Limitations

This study has several limitations. First, our neighborhood assessments were restricted to the 3 time points when the US Census and ACS were conducted (ie, 1990, 2000, and 2010), while weight status was measured from 1995 to 1996 and 2004 to 2006. The difference in the time frame of exposure and outcome measurements may lead to misclassification, as the actual neighborhood changes may have occurred before 1995 or after 2006. In addition, although we restricted our analysis to individuals who reported living in the same area at both baseline and follow-up, we were not able to identify those who moved out of and back into the baseline neighborhood, which may also lead to exposure misclassification. Also, weight status was reported only at baseline and 10 years later, at follow-up, which did not allow us to assess short-term weight fluctuations. Importantly, gaining or losing weight over a short period of time (ie, several months to years) may be associated with a larger change in health outcomes compared with gradual change in weight over years, and more studies are needed to investigate the association between neighborhood environment and short-term weight change. Additionally, participants in our study were predominantly White and had high SES, as measured by college education or higher; therefore, the results may not be generalizable to other racial/ethnic groups and low SES populations, for whom the association between neighborhood SES and weight may differ from that observed among our participants. The relatively high baseline neighborhood SES has limited our ability to assess the potential association between neighborhood improvement and weight change among residents of disadvantaged communities.