Rafael Wlodarski

Variation in the β-endorphin, oxytocin, and dopamine receptor genes is associated with different dimensions of human sociality

Significance Social behavior in mammals is underpinned by a number of social neuropeptides. Most studies, however, focus on a single neuropeptide (often oxytocin), and invariably only in the context of reproductive relationships. Here, we examine the associations between the six main social neuropeptides (endorphins, oxytocin, vasopressin, dopamine, serotonin, and testosterone) and social indices in three separate social domains (disposition, dyadic/romantic relationships, and social network). We show that each neuropeptide is quite specific in its domain of influence, although endorphins and dopamine influence all three social domains. The results suggest that the social importance of endorphins may have been underestimated. There is growing evidence that the number and quality of social relationships have substantial impacts on health, well-being, and longevity, and, at least in animals, on reproductive fitness. Although it is widely recognized that these outcomes are mediated by a number of neuropeptides, the roles these play remain debated. We suggest that an overemphasis on one neuropeptide (oxytocin), combined with a failure to distinguish between different social domains, has obscured the complexity involved. We use variation in 33 SNPs for the receptor genes for six well-known social neuropeptides in relation to three separate domains of sociality (social disposition, dyadic relationships, and social networks) to show that three neuropeptides (β-endorphin, oxytocin, and dopamine) play particularly important roles, with each being associated predominantly with a different social domain. However, endorphins and dopamine have a much wider compass than oxytocin (whose effects are confined to romantic/reproductive relationships and often do not survive control for other neuropeptides). In contrast, vasopressin, serotonin, and testosterone play only limited roles.

Stay or stray? Evidence for alternative mating strategy phenotypes in both men and women.

In all comparative analyses, humans always fall on the borderline between obligate monogamy and polygamy. Here, we use behavioural indices (sociosexuality) and anatomical indices (prenatal testosterone exposure indexed by 2D : 4D digit ratio) from three human populations to show that this may be because there are two distinct phenotypes in both sexes. While males are more promiscuous and display higher prenatal testosterone exposure than females overall, our analyses also suggest that the within-sex variation of these variables is best described by two underlying mixture models, suggesting the presence of two phenotypes with a monogamous/promiscuous ratio that slightly favours monogamy in females and promiscuity in males. The presence of two phenotypes implies that mating strategy might be under complex frequency-dependent selection.

Inference or enaction? The impact of genre on the narrative processing of other minds.

Do narratives shape how humans process other minds or do they presuppose an existing theory of mind? This study experimentally investigated this problem by assessing subject responses to systematic alterations in the genre, levels of intentionality, and linguistic complexity of narratives. It showed that the interaction of genre and intentionality level are crucial in determining how narratives are cognitively processed. Specifically, genres that deployed evolutionarily familiar scenarios (relationship stories) were rated as being higher in quality when levels of intentionality were increased; conversely, stories that lacked evolutionary familiarity (espionage stories) were rated as being lower in quality with increases in intentionality level. Overall, the study showed that narrative is not solely either the origin or the product of our intuitions about other minds; instead, different genres will have different—even opposite—effects on how we understand the mind states of others.

What’s in a Kiss? The Effect of Romantic Kissing on Mate Desirability

Past research suggests that various courtship rituals, such as romantic kissing, may convey useful mate quality information. Two studies were carried out to examine how purported romantic kissing abilities, as a potential cue to some form of mate information, affect appraisals of potential mating partners. In Experiment 1, 724 participants were presented with vignette descriptions of potential mating partners and were asked to rate partner desirability for various mating-related situations. The primary result of this experiment was that purported kissing ability increased mate desirability in “casual sex” mating situations for women to a greater extent than for men. Experiment 2 repeated the same procedure with another 178 participants, this time including visual information alongside vignette descriptions containing kissing-related information to examine the relative effects of these two modalities. It was found that the presence of a picture alongside a descriptive vignette negated the effect of kissing-related information only when rating potential partners on attractiveness or desirability for further courtship, though not when evaluating partners for casual sex or long-term relationship scenarios. Visual information containing “attractive” photos of potential partners was also found to have a greater effect on mens ratings of partner desirability than on womens ratings of partner desirability. The results are discussed in light of romantic kissings potential function of conveying important mate quality and desirability information, and its relative role in the presence of additional visual mate cues.

Functional Benefits of (Modest) Alcohol Consumption

Alcohol use has a long and ubiquitous history. Despite considerable research on the misuse of alcohol, no one has ever asked why it might have become universally adopted, although the conventional view assumes that its only benefit is hedonic. In contrast, we suggest that alcohol consumption was adopted because it has social benefits that relate both to health and social bonding. We combine data from a national survey with data from more detailed behavioural and observational studies to show that social drinkers have more friends on whom they can depend for emotional and other support, and feel more engaged with, and trusting of, their local community. Alcohol is known to trigger the endorphin system, and the social consumption of alcohol may thus have the same effect as the many other social activities such as laughter, singing and dancing that we use as a means of servicing and reinforcing social bonds.

The God Allusion : Individual Variation in Agency Detection, Mentalizing and Schizotypy and Their Association with Religious Beliefs and Behaviors.

It has previously been suggested that the historically and geographically widespread persistence of religious beliefs occurs because it is a by-product of normal cognitive processes, ones which first evolved to confer survival advantages in the social domain. If this theory holds, then it is likely that inter-individual variation in the same biases may predict corresponding variation in religious thoughts and behaviors. Using an online questionnaire, 298 participants answered questions regarding their tendency to detect agency, the degree to which they displayed schizotypal traits, their ability to understand the emotions and motivations of others (“mentalizing”), and their religious beliefs and behaviors. Path analysis suggests that mentalizing, agency detection, and schizotypal thinking were each independently related to religiosity. Furthermore, schizotypal thinking and agency detection were highly interrelated with one another, whereas mentalizing was not. Although the degree to which an individual engages with religious or spiritual beliefs will be influenced by their cultural and historical context, this paper helps to elucidate the interplay between various cognitive processes that might predispose some individuals but not others toward holding such beliefs in the first place.

The Effects of Romantic Love on Mentalizing Abilities.

The effects of the human pair-bonded state of “romantic love” on cognitive function remain relatively unexplored. Theories on cognitive priming suggest that a state of love may activate love-relevant schemas, such as mentalizing about the beliefs of another individual, and may thus improve mentalizing abilities. On the other hand, recent functional MRI (fMRI) research on individuals who are in love suggests that several brain regions associated with mentalizing may be “deactivated” during the presentation of a love prime, potentially affecting mentalizing cognitions and behaviors. The current study aimed to investigate experimentally the effect of a love prime on a constituent aspect of mentalizing—the attribution of emotional states to others. Ninety-one participants who stated they were “deeply in love” with their romantic partner completed a cognitive task involving the assessment of emotional content of facial stimuli (the Reading the Mind in the Eyes task) immediately after the presentation of either a love prime or a neutral prime. Individuals were significantly better at interpreting the emotional states of others after a love prime than after a neutral prime, particularly males assessing negative emotional stimuli. These results suggest that presentation of a love stimulus can prime love-relevant networks and enhance subsequent performance on conceptually related mentalizing tasks.

Reply to Falcon.

We appreciate Falcons [[1][1]] interest in our paper on male and female mating strategies in humans. However, she addresses a rather different issue to the one we were interested in. Her concern is with whether the psychological dispositions implied by the anatomical and sociological indices we