Just kidding: the evolutionary roots of playful teasing

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

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

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

4. Cognitive implications of playful teasing

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

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

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

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

5. Humorous play with others' minds?

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

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

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

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

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

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

Psychological Profile of Extreme Trump Supporters: Many of these tendencies generalize to extreme Trump opposition, meaning that Trump support is in many ways an extrapolation of a long-standing and escalating Culture War

A Psychological Profile of Extreme Trump Supporters. Laura Kinsman & Jeremy A. Frimer. Sep 2020. http://www.jeremyfrimer.com/uploads/2/1/2/7/21278832/kinsman___frimer__in_press_.pdf

Abstract: Donald Trump once claimed that he could murder someone in broad daylight and still not lose support, implying an extreme loyalty on the part of his supporters. The psychological foundation of this purported commitment is far from obvious in that many aspects of Trump’s lifestyle, personality, policies, and values are antithetical to those cherished by large segments of his base (e.g., Evangelical Christians, free trade advocates). Political scholars, pundits and the media have offered a number of explanations for the support for Trump that exists within his base. In this chapter, we review three of the more common media explanations, which include tribal loyalties, selective media exposure, and material self-interest, and find some support for each in the scientific literature, with support generally being weaker for the more nefarious explanation (e.g., tribal racism, bloodlust) and stronger for more banal explanations (e.g., information bubbles, perceived self-interest). We also find that many of these tendencies generalize to extreme Trump opposition, meaning that Trump support is in many ways an extrapolation of a long-standing and escalating Culture War.

Thanksgiving Dinners: Politics is not straining family ties as much as previously thought

Are Politically Diverse Thanksgiving Dinners Shorter Than Politically Uniform Ones? In press in PLOS One. Jeremy A. Frimer & Linda J. Skitka. http://www.jeremyfrimer.com/uploads/2/1/2/7/21278832/frimer_skitka_in_press_.pdf

Abstract: Americans on the political left and right are engaged in a Culture War with one another, one that is often characterized by mutual fear, antipathy, and avoidance. Are there safe havens from the socially straining effects of this Culture War, times and places where Americans of different political stripes gather and put aside their political differences? Previous research (Chen & Rohla, 2018) implied that there might not be insofar as even intimate family gatherings seem to be subject to Culture War tensions. They found that politically diverse Thanksgiving Dinners were 35-70 minutes shorter than politically uniform ones, representing a 14-27% reduction in overall dinner duration. Noting analytical and methodological limitations in the prior analysis, we conducted two pre-registered studies to test whether diverse dinners are shorter than uniform ones and to attempt to conceptually replicate and extend this prior analysis. Individual analyses yielded mixed results, with null models generally supported but effect estimates generally overlapping with those of Chen and Rohla (2018). A mega-analysis found that, when controlling for various covariates, politically diverse dinners were 24 minutes shorter than politically uniform ones, 95% confidence interval = [9, 39], representing a 6% decrease in the total dinner time [2%-10%]. This final result successfully replicates Chen and Rohla (2018) both in terms of effect overlap and direct-and-significance criteria while nonetheless favoring the conclusion that politics is not straining family ties as much as previously thought.

Keywords: liberals and conservatives, intergroup relations, Culture War, Thanksgiving, selective exposure

Starks & colleagues speculated that HIV infection could alter host behavior in a manner that facilitated the spread of the virus; retrospective and self-report data from five studies now support this hypothesis

Does HIV infection increase male sexual behavior? Philip T Starks, Maxfield M G Kelsey, David Rosania, Wayne M Getz. Evolution, Medicine, and Public Health, eoaa030, September 16 2020. https://doi.org/10.1093/emph/eoaa030

Abstract: After 40 years of intense study on HIV/AIDS, scientists have identified, amongst other things, at risk populations, stages of disease progression, and treatment strategies. What has received less attention is the possibility that infection might elicit an increase in sexual behavior in humans. In 2000, Starks and colleagues speculated that HIV infection could alter host behavior in a manner that facilitated the spread of the virus. Retrospective and self-report data from five studies now support this hypothesis. Individuals with acute – versus nonacute – stage infections report more sexual partners and more frequent risky sex. Additionally, male sexual behavior increases non-linearly with HIV viral load, and data suggest a potential threshold viral level above which individuals are more likely to engage in risky sexual behavior. Taken together, these data suggest that HIV infection influences male sexual behavior in a manner beneficial to the virus. Here, we present these findings, highlight their limitations, and discuss alternative perspectives. We argue for increased testing of this hypothesis and advocate for increased public health measures to mitigate the putative impact on male sexual behavior.

Lay Summary: In 2000, Starks and colleagues speculated that HIV infection could alter host behavior in a manner that facilitated the spread of the virus. Retrospective and self-report data from five studies now support this hypothesis. We argue for increased testing of this hypothesis and advocate for increased public health measures to mitigate the putative impact on male sexual behavior.

Topic: hivdisease progressionsex behaviorsexual partnersviral load resultinfectionspublic health medicineviruseshiv infectionsself-report

Compensatory conspicuous communication: Low status increases jargon use; experiments provided a causal link from low status to jargon use

Compensatory conspicuous communication: Low status increases jargon use. Zachariah C. Brown, Eric M. Anicich, Adam D. Galinsky. Organizational Behavior and Human Decision Processes, Volume 161, November 2020, Pages 274-290. https://doi.org/10.1016/j.obhdp.2020.07.001

Highlights

• Experiencing low status increases the use of jargon.

• Low status increases jargon use because it activates evaluative concerns.

• Archival analyses found a low status → jargon effect across 64 k dissertation titles.

• Experiments provided a causal link and mediation path from low status to jargon use.

• The use of acronyms also serves a status compensation function.

Abstract: Jargon is commonly used to efficiently communicate and signal group membership. We propose that jargon use also serves a status compensation function. We first define jargon and distinguish it from slang and technical language. Nine studies, including experiments and archival data analyses, test whether low status increases jargon use. Analyses of 64,000 dissertations found that titles produced by authors from lower-status schools included more jargon than titles from higher-status school authors. Experimental manipulations established that low status causally increases jargon use, even in live conversations. Statistical mediation and experimental-causal-chain analyses demonstrated that the low status → jargon effect is driven by increased concern with audience evaluations over conversational clarity. Additional archival and experimental evidence found that acronyms and legalese serve a similar status-compensation function as other forms of jargon (e.g., complex language). These findings establish a new driver of jargon use and demonstrate that communication, like consumption, can be both compensatory and conspicuous.

Rolf Degen summarizes: People willingly accept inconveniences in order to satisfy their curiosity, even if the sought for information is unpleasant or will put them in a bad mood

The seductive lure of curiosity: information as a motivationally salient reward. Lily Fitz Gibbon, Johnny King LLau, Kou Murayama. Current Opinion in Behavioral Sciences, Volume 35, October 2020, Pages 21-27. https://doi.org/10.1016/j.cobeha.2020.05.014

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308270412439093249

Highlights

• Curiosity is a powerful motivator of information-seeking behavior.

• People risk negative experiences to satisfy curiosity.

• Empirical evidence reveals parallels between information and extrinsic rewards.

• Incentive salience may provide motivation for information beyond its expected value.

Abstract: Humans are known to seek non-instrumental information, sometimes expending considerable effort or taking risks to receive it, for example, ‘curiosity killed the cat’. This suggests that information is highly motivationally salient. In the current article, we first review recent empirical studies that demonstrated the strong motivational lure of curiosity – people will pay and risk electric shocks for non-instrumental information; and request information that has negative emotional consequences. Then we suggest that this seductive lure of curiosity may reflect a motivational mechanism that has been discussed in the literature of reward learning: incentive salience. We present behavioral and neuroscientific evidence in support of this idea and propose two areas requiring further investigation – how incentive salience for information is instigated; and individual differences in motivational vigor.

Rolf Degen summarizes... Large parts of our life are governed by "phantom rules", flexible clauses whose violation we only find offensive when we see fit

Wylie, Jordan, and Ana P. Gantman. 2020. “Doesn’t Everybody Jaywalk? On the Motivated Enforcement of Frequently Violated Rules.” PsyArXiv. September 21. doi:10.31234/osf.io/yfsed

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308255026767372288

Abstract: We propose the existence of a subclass of explicitly codified rules— phantom rules—whose violations are frequent, and whose enforcement is motivated (e.g., jaywalking). These rules differ from other rules (e.g., no traveling in basketball) and laws (e.g., theft) because they do not appear legitimate. Across three experiments, we recruited U.S. participants from Amazon MechanicalTurk and Prolific (N = 464) and validated each feature of our definition. In Experiment 1, participants classified phantom rules as illegal and frequent. In Experiment 2, we found that phantom rules (vs. social norms) are more morally acceptable, but more justifiably punished, allowing for the motivated enforcement found in Experiment 3. We hypothesized and found people judge phantom rule violations to be more justifiably enforced when they were already motivated to punish. Phantom rule violations are judged to be morally worse and more justifiably punished when the person who violated the phantom rule also violated a social norm (vs. phantom rule violation alone). Phantom rules are codified rules, frequently violated, and enforced in a motivated manner.

Criminalization of sex work increases sexually transmitted infections among female sex workers by 58 pct, driven by decreased condom access & use; earnings among women decreased, making easier that children begin working to supplement income

 Crimes Against Morality: Unintended Consequences of Criminalizing Sex Work. Lisa Cameron, Jennifer Seager, Manisha Shah. NBER Working Paper No. 27846, September 2020. https://www.nber.org/papers/w27846

Abstract: We examine the impact of criminalizing sex work, exploiting an event in which local officials unexpectedly criminalized sex work in one district in East Java, Indonesia, but not in neighboring districts. We collect data from female sex workers and their clients before and after the change. We find that criminalization increases sexually transmitted infections among female sex workers by 58 percent, measured by biological tests. This is driven by decreased condom access and use. We also find evidence that criminalization decreases earnings among women who left sex work due to criminalization, and decreases their ability to meet their children's school expenses while increasing the likelihood that children begin working to supplement household income. While criminalization has the potential to improve population STI outcomes if the market shrinks permanently, we show that five years post-criminalization the market has rebounded and the probability of STI transmission within the general population is likely to have increased.

63-year-old man, after gunshot to the head, became “content,” light-hearted, and prone to joking and punning; prior to his brain injury, he suffered from frequent depression and suicidal ideation

Positive Emotions from Brain Injury: The Emergence of Mirth and Happiness. Mario F. Mendez and Leila Parand. Case Reports in Psychiatry, Volume 2020, Article ID 5702578, Jan 29 2020. https://doi.org/10.1155/2020/5702578

Rolf Degen's take: https://twitter.com/DegenRolf/status/1308081276965064706

Abstract: Brain injury can result in an increase in positive emotions. We describe a 63-year-old man who presented with a prominent personality change after a gunshot wound to the head. He became “content,” light-hearted, and prone to joking and punning. Prior to his brain injury, he suffered from frequent depression and suicidal ideation, which subsequently resolved. Examination showed a large right calvarial defect and right facial weakness, along with memory impairment and variable executive functions. Further testing was notable for excellent performance on joke comprehension, good facial emotional recognition, adequate Theory of Mind, and elevated happiness. Neuroimaging revealed loss of much of the right frontal and right anterior lobes and left orbitofrontal injury. This patient, and the literature, suggests that frontal predominant injury can facilitate the emergence of mirth along with a sense of increased happiness possibly from disinhibited activation of the subcortical reward/pleasure centers of the ventral striatal limbic area.

3. Discussion

This patient had a heightened sense of mirth and happiness after his brain injury. The loss of much of his right frontal and right anterior temporal lobes, and damage to left orbitofrontal cortex, altered his personality towards not just silly joking consistent with Witzelsucht but an actual increase in his appreciation of humor. He also maintained a very positive outlook and increased apparent happiness or contentment, per his report. On examination, he was able to detect jokes and identify them as funny, and he consistently described himself as very happy despite his brain injury and situation.

Beyond his joking or “Witzelsucht” from the German words for joke (Witz) and addiction (Sucht) [4, 5], this patient had increased mirth. Mundane experiences and others’ jokes caused him amusement. Investigators have characterized the neurobiology of humor as involving several modular aspect [1, 13]. The first is the cognitive aspect, or getting the joke, namely, the perception of incongruity or of incompatibility between an anticipated perspective and the punchline. Second, with resolution of the incongruity, there is the actual humor appreciation or mirth involving the dopaminergic pleasure/reward centers of the ventral striatum and nucleus accumbens (VS/NA) [14–16]. The frontal lobes participate in incongruity detection and resolution, with the left frontal more responsive to simple humor [16–18], and the right more engaged with complex humor [14, 19–21]. In addition, other regions may contribute to incongruity detection and resolution, such as the temporoparietal junction, the precuneus, the posterior cingulate cortex, and the parahippocampal gyrus [22]. Once incongruity is resolved, the new explanation triggers emotionally pleasurable responses experienced as mirth [9, 14, 15, 23, 24]. Since this patient could “get a joke,” his changes appeared at the level of the ease of elicitation of mirth.

The regions associated with the experience of mirth include the VS/NA as well as connections from the anterior cingulate gyrus (ACG), posterior insula, and frontal (left>right) lobe [25–28]. Deep brain stimulation of the VS/NA induces mirth and enhances effective connectivity from the ACG to the VS [25, 26]. As well as promoting surprise, electrical stimulation of the rostral pregenual ACG can also elicit laughter with mirth [27, 29, 30]. The experience of mirth can occur with the rerepresentation and integration of interoceptive information in the insula [28]. Finally, the frontal lobes trigger humor appreciation through connections with these structures [14–16, 20, 29, 31, 32].

The formation and regulation of happiness seem to be associated with significant reductions in activity in the right prefrontal cortex, as well as increased activity in the VS/NA [33]. The left frontal lobe may produce a default state biased towards happy or positive interpretations [34]. For example, cortical sites that produce mirth when stimulated tend to be located in the dominant hemisphere close to language areas [35, 36]. Furthermore, disruption of left frontostriatal emotion regulation systems can impair the ability to suppress positive emotions such as happiness [37]. Together, these findings, as well as the patient’s increased appreciation of humor, suggest that his brain lesion facilitated or released his VS/NA area from any negative input or inhibition. This view must be interpreted cautiously from the analysis of a single patient. There may be other explanations for the patient’s positive emotions, such as the simple relief from depression after his head injury, or as a result of alleviation of stress from no longer functioning as a minister. Nevertheless, his personality change was quite dramatic shortly after recovering from his gunshot wound to the head.

We conclude that positive emotions such as mirth and happiness can emerge from brain lesions and persist. The loss of much of the right frontal and right anterior temporal lobes and damage to the left orbitofrontal cortex facilitated a positive sense of amusement and a positive outlook described as “contentment” by this patient. The literature suggests that this can occur in patients with predominant damage to the right frontal lobe, but also affecting left frontostriatal circuits. These observations warrant further investigation as they speak to the source of positive emotions in humans.

When unethically-earned money is first "laundered" -the cash is physically exchanged for the same amount but from a different arbitrary source- people spent it as if it was earned ethically

 Mental Money Laundering: A Motivated Violation of Fungibility. Alex Imas, George Loewenstein & Carey Morewedge. Carnegie Mellon University Working Paper, September 8 2020. https://ssrn.com/abstract=3662841

Abstract: People exploit flexibility in mental accounting to relax psychological constraints on spending. Four studies demonstrate this in the context of moral behavior. The first study replicates prior findings that people donate more money to charity when they earned it through unethical versus ethical means. However, when the unethically-earned money is first "laundered" - the cash is physically exchanged for the same amount but from a different arbitrary source - people spent it as if it was earned ethically. This mental money laundering represents an extreme fungibility violation: exchanging "dirty" money for the same sum coming from a "clean" source significantly changed people's propensity to spend it prosocially. The second study demonstrates that mental money laundering generalizes to cases in which ethically and unethically earned money is mixed. When gains from ethical and unethical sources were pooled, people spent the entire pooled sum as if it was ethically earned. The last two studies provide mixed support for the prediction that people actively seek out laundering opportunities for unethically earned money, suggesting partial sophistication about these effects. These findings provide new evidence for the ease with which people can rationalize misbehavior, and have implications for consumer choice, corporate behavior and public policy.

Why do we have big gluteal muscles?

Why do we have big gluteal muscles? Daniel Kolitz. Gizmodo, September 21, 2020. https://www.gizmodo.com.au/2020/09/why-do-we-have-butts/

Some experts gave their opinion in 2018. Among them, Jason Bourke, Paleontologist and Assistant Professor of Anatomy, New York Institute of Technology College of Osteopathic Medicine at Arkansas State:

The structures we refer to as butt cheeks in humans are comprised of the gluteal muscles: gluteus minimus, gluteus medius, and gluteus maximus. Of the three gluteal muscles, gluteus maximus is responsible for the signature shape of the human derriere. It originates from a line that runs from our upper ilium (the pelvic bone that people often call their hips) down towards our coccyx (tailbone). The muscle attaches close to the top of our femur (thigh bone). The gluteus maximus functions as our major leg extensor and is the main driver of our legs when running, climbing stairs, getting up from a seated position etc. It’s the powerhouse muscle we call upon whenever we need to perform major postural changes, or when we need to move our legs fast. That’s why sprinters, and weightlifters that do heavy-weighted squats tend to have very round and firm buttocks (i.e., “squat butt”).

Because the muscle originates and inserts across a fairly small distance, it needs to produce a lot of force to get our legs to move. This makes the muscle very large, but since there is not a lot of space for the muscle to sit, the muscle fibres expand outwards and – thanks to gravity – downwards resulting in our hallmark hind ends.

The shape of our rear end is practically unique to our species. As we transitioned from quadrupedal apes to bipedal ones, our pelvis underwent radical changes to handle the weight of our entire torso resting on top of it. This required substantial reorientation of many of our hip muscles and it put our major leg extensor (gluteus maximus) in this weird position where it seems to almost hang off of our pelvis. There are a few other species of mammals that have what we might term “butt cheeks”. Namely horses, which show substantial developments of their rear ends as well. As with humans, well-developed gluteal muscles are responsible for the roundness of horse butts. However, unlike humans, horses achieved this shape via expansion of a different gluteal muscle, their gluteus medius. In fact, a large gluteus medius is pretty standard for most mammals. Humans are unique in expanding our gluteus maximus instead, which is no doubt a response to the unique physical demands of our strange way of walking.

Moral Choice When Harming Is Unavoidable

Moral Choice When Harming Is Unavoidable. Jonathan Z. Berman, Daniella Kupor. Psychological Science,  September 8, 2020. https://doi.org/10.1177/0956797620948821

Abstract: Past research suggests that actors often seek to minimize harm at the cost of maximizing social welfare. However, this prior research has confounded a desire to minimize the negative impact caused by one’s actions (harm aversion) with a desire to avoid causing any harm whatsoever (harm avoidance). Across six studies (N = 2,152), we demonstrate that these two motives are distinct. When decision-makers can completely avoid committing a harmful act, they strongly prefer to do so. However, harming cannot always be avoided. Often, decision-makers must choose between committing less harm for less benefit and committing more harm for more benefit. In these cases, harm aversion diminishes substantially, and decision-makers become increasingly willing to commit greater harm to obtain greater benefits. Thus, value trade-offs that decision-makers refuse to accept when it is possible to completely avoid committing harm can suddenly become desirable when some harm must be committed.

Keywords: moral choice, value trade-offs, harm aversion, harm avoidance, protected values, open data, open materials, preregistered

General Discussion

Across six studies, we demonstrated that the preference to avoid inflicting any harm not only is distinct from but also outweighs the preference to minimize its impact. Our results suggest that the manner in which individuals bracket instances of harm affects their willingness to commit harm (cf. Read, Loewenstein, Rabin, Keren, & Laibson, 1999). For instance, individuals may be more reluctant to commit a second violation a month after a first violation than they would be if the second violation occurred just moments after the first. This is because the two harmful actions may be more likely to be bracketed together in the latter case and may thus be perceived as an unavoidable-harm context.

Although we focused our examination on decisions impacting social welfare, similar outcomes may occur for decisions that are exclusively self-relevant. For instance, research suggests that individuals are particularly averse to holding debt if they do not need to be in debt but prefer to take on more debt to maintain their assets if holding debt is unavoidable (Sussman & Shafir, 2012).

Finally, in Study 4, we found that even when greater harm produced diminishing marginal benefits, individuals were still more willing to commit greater harm than when it was possible to commit no harm. However, there is likely a threshold for which committing more harm is no longer perceived as worthwhile. Future research can investigate factors that affect this threshold.

In sum, we found that decision-makers who can completely avoid committing a harmful act frequently choose to do so. However, when committing some harm is unavoidable, decision-makers become increasingly willing to trade off greater harm for greater benefits.

Older chimpanzees have more propensities to engage with others

Shifting sociality during primate ageing. Zarin P. Machanda and Alexandra G. Rosati. Philosophical Transactions of the Royal Society B: Biological Sciences. September 21 2020. https://doi.org/10.1098/rstb.2019.0620

Rolf Degen's take: https://twitter.com/DegenRolf/status/1307911120343183360

Abstract: Humans exhibit major age-related shifts in social relationships along with changes in social and emotional psychological processes that underpin these behavioural shifts. Does social ageing in non-human primates follow similar patterns, and if so, what are the ultimate evolutionary consequences of these social shifts? Here we synthesize empirical evidence for shifts in social behaviour and underlying psychological processes across species. Focusing on three elements of social behaviour and cognition that are important for humans—propensities to engage with others, the positive versus negative valence of these interactions, and capabilities to influence others, we find evidence for wide variation in the trajectories of these characteristics across primates. Based on this, we identify potential modulators of the primate social ageing process, including social organization, sex and dominance status. Finally, we discuss how comparative research can contextualize human social ageing.

Culture among animals is most likely more widespread and pervasive than commonly thought and an important avenue to local adaptation; we most likely built upon a very broad, pre-existing cultural capacity

Animal cultures: how we've only seen the tip of the iceberg. Caroline Schuppli and Carel P. van Schaik. Evolutionary Human Sciences, Volume 1 2019, e2, May 9 2019. https://doi.org/10.1017/ehs.2019.1

Abstract: For humans we implicitly assume that the way we do things is the product of social learning and thus cultural. For animals, this conclusion requires proof. Here, we first review the most commonly used procedure for documenting animal culture: the method of exclusion, which charts geographic behavioral variation between populations as evidence for culture. Using published data, we show that, whereas it is an adequate proof of principle, the method of exclusion has major deficiencies when capturing cultural diversity and complexity. Therefore, we propose a new method, namely the direct counting of socially learned skills, which we apply to previously collected data on wild orangutans. This method reveals a far greater cultural repertoire among orangutans, and a different distribution of cultural elements among behavioral domains than found by the method of exclusion, as well as clear ecological correlates for most cultural elements. The widespread occurrence of social learning ability throughout the animal kingdom suggests that these conclusions also apply to many other species. Culture is most likely more widespread and pervasive than commonly thought and an important avenue to local adaptation. The complex and normative dimensions of culture seem unique to our species, but were most likely built upon a very broad, pre-existing cultural capacity that we inherited from our ancestors.

Discussion

The base of the great ape culture iceberg

The orangutan example suggests that by relying on the MoE to assess cultural repertoires we have so far only discovered the tip of the great ape culture iceberg (i.e. C ₁ >> C_ME; Figure 4). The MoE produces a biased sample of highly complex and conspicuous behaviors and dismisses a vast array of socially learned behaviors that covary with ecological factors. By counting socially learned skills, however, we are beginning to get to know the base of this iceberg. Cultural repertoires are mainly composed of basic, low-complexity subsistence skills, most of which show clear ecological correlates (e.g. knowledge of diet composition and processing techniques). Thus, a lot of (but not all) cultural variation may indeed be ecologically induced (C _Ecol is a major part of C ₁ and C _Var).

At the same time, a systematic reliance on social learning under similar ecological conditions may very well lead to many universal cultural behavior patterns across populations. The most striking example in the orangutans for this is nest building: even though it is an orangutan universal, it takes young orangutans years of close observation and subsequent practice before they can build nests good enough to spend the night in (Schuppli et al., 2016a), and socially deprived young apes will never be able to do so (Bernstein, 1962; Videan, 2006). The basic construction of nests (a rim made of intertwined long branches) is highly comparable across different orangutan populations, presumably because it is the most latent solution to the problem (Tennie et al., 2009; high C _U but low C _Ecol).

How much culture is there in other animals?

The points discussed above are unlikely to be true only for orangutans or great apes in general but most certainly apply to all species that rely on social learning. Although numerous species, including insects, fish, birds and mammals, are now known to be capable of social learning (reviewed by Galef and Laland, 2005; Rapaport and Brown, 2008; Reader and Biro, 2010; Whiten, 2017), for most, social learning has so far only been shown in captivity, which does not elucidate to what extent species indeed use this ability in the wild (Reader and Biro, 2010; Whiten and van de Waal, 2018). Even though behavioral scientists now increasingly acknowledge the role of social learning (van Schaik and Burkart, 2011; Tomasello, 1999; van Schaik et al., 2017), it is still widely treated as the rare and complex exception under the skill acquisition modes.

However, social learning can be quite simple given that many forms of social learning (e.g. enhancement or facilitation) do not require higher forms of cognition but nonetheless produce faithful behavioral copies owing to shared affordances. Furthermore, from the perspective of naïve immatures, a strong reliance on social learning is highly adaptive because social learning is less dangerous and more efficient than independent learning: it reduces the risk of getting injured or poisoned, increases learning speed by allowing the learning individual to benefit from what others have figured out before and increases the signal strength of relevant information (van Schaik and Burkart, 2011). Social learning thus allows for the fast acquisition of skills and the acquisition of more complex skills, and naïve individuals will benefit from choosing this option whenever they can. As such, we expect social learning to be most prominent in species with contact between generations, high social tolerance toward immatures, and an extended period of immaturity.

Over the last two decades it has become increasingly clear that social learning is indeed an important means of natural skill acquisition for many mammal and bird species, as evidenced in inherited dietary specializations, selective observations of skilled individuals, master apprentice interactions, effects of the presence of role models on foraging success or links between social networks and skill repertoires (Coelho et al., 2015; Estes et al., 2003; Griesser and Suzuki, 2016; Guinet and Bouvier, 1995; Hobaiter et al., 2014; Kitowski, 2009; Krutzen et al., 2005; Lonsdorf, 2006; Mann et al., 2007; Matsuzawa et al., 2001; Ottoni et al., 2005; Rapaport and Brown, 2008; Schuppli et al., 2016a). Direct observations of the spread of recently made innovations through social groups are bound to be rare but have been made in natural populations (Allen et al., 2013; Hobaiter et al., 2014; Kendal et al., 2010). Interspecific cross-fostering experiments, be they designed or accidental, although both quite rare, have impressively demonstrated the pervasiveness of social learning of life's skills (Rowley and Chapman, 1986; Sheppard et al., 2018; Slagsvold and Wiebe, 2007; Warner, 1988).

Culture is therefore likely to be pervasive in all species that pass on knowledge and skills socially. However, most of these species’ skills will show little or no geographic variation, except for the most complex skills, which are the least likely to be invented and retained. In several species, the acquisition of basic foraging skills was shown to be socially mediated: in aye-ayes (Daubentonia madagascariensis), for example, immatures learn tap-foraging – for which they even have morphological specializations – far less readily in the absence of adult role models (Krakauer, 2005).

Since social learning can be very simple, culture does not require a large brain and it is therefore unlikely to be a hallmark of cognitive complexity (Byrne et al., 2004; Laland and Hoppitt, 2003), although the efficiency of cultural transmission may also favor the evolution of greater investment in brains (van Schaik and Burkart, 2011).

Remaining challenges in the animal culture debate

Detecting animal culture irrespective of geographic variation is challenging and may not always be possible. Aside from peering, social learning can also happen via observation at longer distances, socially induced encounters with environmental features and acoustic transmission. Thus, in order to be able to draw conclusions about and compare cultural repertoires across species, it is crucial to find appropriate ways to detect social learning according to the species’ main transmission mode as well as to take different transmission modes into account. The SLS will thus most likely only rarely produce integral cultural repertoires. In most cases, however, it will be able to lift a significant part of the so far hidden base of the culture iceberg above the surface.

Implications for human culture

Most elements which we nowadays naturally call the product of human culture can be found across the globe and are thus human universals. In this time of increasing connectedness and global exchange even the most complex human innovations often quickly reach the status of universals and would not be recognized as socially learned innovations by their geographic distribution. Yet everyone would agree that these innovations are an important part of our cultural repertoire.

What differentiates animal from human culture is the lack of normativity, the virtual absence of cumulative culture and the enormous diversity of human cultural elements (Laland and Galef, 2009; Whiten, 2017; Whiten and van Schaik, 2007). These three features seem to remain a hallmark of human culture and seem to be linked to the evolution of our species’ skill-intensive, technology-dependent foraging niche (van Schaik et al., 2019; Laland, 2017). However, the unique human cultural constellation was built on a surprisingly broad and evolutionarily deep foundation.

Like psychology more broadly, developmental psychology has long suffered from a narrow focus on children from WEIRD societies

Cross-cultural, developmental psychology: integrating approaches and key insights. Dorsa Amir, Katherine McAuliffe. Evolution and Human Behavior, Volume 41, Issue 5, September 2020, Pages 430-444. https://doi.org/10.1016/j.evolhumbehav.2020.06.006

Abstract: Like psychology more broadly, developmental psychology has long suffered from a narrow focus on children from WEIRD societies—or those that are Western, Educated, Industrialized, Rich, and Democratic. In this review, we discuss how developmental scientists have sought to correct this bias through two complementary approaches: one centered on detailed, ethnographic investigations of child development within populations (increasing the depth of our understanding) and one focused on larger, multi-site studies that test children on standardized tasks across populations (increasing breadth). We review key papers from each of these approaches, describe how they are currently practiced, and discuss their strengths and weaknesses. Next, we highlight exemplary papers from the adult literature that offer useful insights, namely the importance of formal modeling and a greater focus on studying variation at multiple levels of analysis. We end by outlining best practices for future waves of cross-cultural, developmental science. Overall, we argue that a more integrated perspective, combining the strengths of the breadth & depth approaches, can help better elucidate the developmental origins of human behavioral diversity.

Keywords: DevelopmentCross-cultural psychologyDevelopmental psychologyWEIRD

Daily politics is a stressor: Understandably, people frequently tried to regulate their politics-induced emotions using cognitive strategies (reappraisal and distraction); this regulation predicted greater well-being

Feinberg, Matthew, Brett Q. Ford, Sabrina Thai, Arasteh Gatchpazian, and Bethany Lassetter. 2020. “The Political Is Personal: Daily Politics as a Chronic Stressor.” PsyArXiv. September 19. doi:10.31234/osf.io/hdz97

Rolf Degen's take: https://twitter.com/DegenRolf/status/1307539072177582081

Abstract: Politics and its controversies have permeated everyday life, but the daily impact of politics is largely unknown. Here, we conceptualize politics as a chronic stressor with important consequences for people’s daily lives. We used longitudinal, daily-diary methods to track U.S. participants as they experienced daily political events across two weeks (Study 1: N=198, observations=2,167) and, separately, across three weeks (Study 2: N=811, observations=12,790) to explore how daily political events permeate people’s lives and how they cope with this influence of politics. In both studies, daily political events consistently evoked negative emotions, which corresponded to worse psychological and physical well-being, but also increased motivation to take political action (e.g., volunteer, protest) aimed at changing the political system that evoked these emotions in the first place. Understandably, people frequently tried to regulate their politics-induced emotions; and successfully regulating these emotions using cognitive strategies (reappraisal and distraction) predicted greater well-being, but also weaker motivation to take action. Although people can protect themselves from the emotional impact of politics, frequently-used regulation strategies appear to come with a trade-off between well being and action. To examine whether an alternative approach to one’s emotions could avoid this trade-off, we measured emotional acceptance in Study 2 (i.e., accepting one’s emotions without trying to change them) and found that successful acceptance predicted greater daily well-being but no impairment to political action. Overall, this research highlights how politics can be a chronic stressor in people’s daily lives, underscoring the far-reaching influence politicians have beyond the formal powers endowed unto them.

Longitudinal data from the Child Development Project: Parental psychological control perceived at age 16 predicts insecure attachment at age 18, which then predicts psychological intimate partner violence at age 24

Psychological Intimate Partner Violence, Insecure Attachment, and Parental Psychological Control from Adolescence to Emerging Adulthood. So Young Choe, Jungeun Olivia Lee, Stephen J. Read. Journal of Interpersonal Violence, September 15, 2020. https://doi.org/10.1177/0886260520957974

Abstract: We examine if psychological intimate partner violence (pIPV) is predicted by parental psychological control (PPC) via insecure attachment. Our results analyzing longitudinal data from the Child Development Project show that PPC perceived at age 16 predicts insecure attachment at age 18, which then predicts pIPV at age 24. Moreover, the paths with attachment anxiety are consistently significant while ones with attachment avoidance are not. Further, all the paths are significant regardless of the gender of the adolescents and parents, which indicates that PPC is detrimental regardless of the gender of the adolescents or parents. Lastly, PPC perceived at age 16 does not directly predict pIPV at age 24, which suggests that social learning theory of aggression (Bandura, 1978) may not explain the association from PPC to pIPV. Our results suggest that research and practice would benefit by considering PPC as an antecedent of pIPV via insecure attachment from adolescence to emerging adulthood.

Keywords: parental psychological control, attachment, intimate partner violence

93 math teachers grading exam papers: those who underestimated their own implicit stereotypes engaged in more pro-male discrimination compared to those who overestimated or accurately estimated them

On the Origins of Gender-Biased Behavior: The Role of Explicit and Implicit Stereotypes. Eliana Avitzour, Adi Choen, Daphna Joel, Victor Lavy. NBER Working Paper No. 27818, September 2020. https://www.nber.org/papers/w27818

Abstract: In recent years, explicit bias against women in Science, Technology, Engineering and Math (STEM) is disappearing but gender discrimination is still prevalent. We assessed the gender-biased behavior and related explicit and implicit stereotypes of 93 math teachers to identify the psychological origins of such discrimination. We asked the teachers to grade math exam papers and assess the students’ capabilities while manipulating the perceived gender of the students to capture gender-biased grading and assessment behavior. We also measured the teachers’ implicit and explicit stereotypes regarding math, gender, and talent. We found that implicit, but not explicit, gender stereotypes correlated with grading and assessment behavior. We also found that participants who underestimated their own implicit stereotypes engaged in more pro-male discrimination compared to those who overestimated or accurately estimated them. Reducing implicit gender stereotypes and exposing individuals to their own implicit biases may be beneficial in promoting gender equality in STEM fields.