Adaptive Human Behavior and Physiology最新文献

Objectives

Previous studies have shown that body size and height affect one’s perceived optimal distance during social interactions. This current study is built up on the previous research that found a relationship between men’s height and comfort distance but failed to find any effect of men’s shoulder-hip ratio (SHR) on one’s comfort distance. The current study investigated the combined effect of SHR and height to eliminate methodological issues that prevented from establishing an effect of SHR in the previous study.

Methods

In this study, a total of 49 participants (both men and women) reported their comfort distance in relation to 63 male avatars that differed in height from 150 to 190 cm (9 values) and in SHR from 1 to 1.3 ratio (7 values).

Results and Conclusion

The result of this study showed that both genders had an increment of their comfort distance as the height of the avatar increased. The effect of SHR on comfort distance was only evident with extreme SHR measurements; demonstrating that height is a better indicator of establishing comfort distance during interactions.

Objective

The vast majority of research on biobehavioral influences on development has focused on mothers and infants, whereas research on paternal biobehavioral influences remains sparse. This study aims to increase understanding of paternal influences on the biobehavioral dynamics of the family unit, using a multi-system approach.

Methods

Participants consisted of 32 predominantly high-risk families recruited during pregnancy who completed monthly questionnaires and in-home visits when infants were 4, 12, and 18 months of age. In-home visits included semi-structured interaction tasks and saliva samples for cortisol and progesterone assays.

Results

Mothers and infants, but not fathers and infants, showed adrenocortical attunement, with the strongest attunement at 18 months. Second, mothers’ couple satisfaction did not significantly impact infants’ cortisol levels or mother-infant cortisol attunement, but mothers’ progesterone moderated the relationship between couple satisfaction and infant cortisol levels such that mothers with low couple satisfaction, but high progesterone, had infants with lower cortisol levels. Finally, mothers’ and fathers’ progesterone levels were attuned across the time points.

Conclusions

This is some of the first evidence of the establishment of the family biorhythm and suggests that fathers play an indirect role in facilitating mother-infant adrenocortical attunement.

Purpose

The purpose of the current study was to examine age-related change in state and trait boredom in 12- to 17-year-old adolescents and test whether neurophysiological correlates of self-regulation relate to boredom during adolescence in the same way that has been found in adults.

Methods

Eighty-nine 12- to 17-year-old adolescents participated. Three types of trait boredom were measured: boredom proneness, leisure boredom, and boredom susceptibility. State boredom was also measured after completing a boredom induction task while EEG was recorded. Slopes in frontal alpha asymmetry (FAA) were extracted from the EEG as a measure of approach (leftward shifts) or avoidance (rightward shifts).

Results

A curvilinear relationship between age and boredom proneness and age and boredom susceptibility was observed, indicating trait boredom rises and falls across adolescence. State boredom, by contrast, increased linearly with age. Slopes in FAA inversely related only to boredom proneness, indicating higher levels of this type of trait boredom related to an avoidant response as a state of boredom ensues.

Conclusion

We suggest the rise and fall of trait boredom across adolescence may be due to changes in person-environment fit during middle adolescence, whereas state boredom may increase with age due to improvements in attentional processes that mundane lab tasks do not satisfactorily engage. The link between FAA and only one type of trait boredom indicates self-regulatory processes and boredom are not yet strongly coupled in adolescence. Implications for prevention of negative behavioral health outcomes associated with high levels of trait boredom are discussed.

Objectives

Human females may attract men and solicit their approach through different nonverbal displays and signals. In many non-human animals, a lordosis posture in a female is a reliable signal of sexual receptivity. Recently, it has been argued that this posture is linked to a similar signal between men and women. The current research across three investigations aimed to test the predictions arising from the sexual receptivity hypothesis of lordosis posture.

Methods

Using realistic 3D generated stimuli, both men and women viewed women’s arched back postures in standing, supine and quadruped poses (Studies 1 and 2) and were asked to rate them for perceived sexual receptivity. In Study 3, a male model was used.

Results

In Study 1 we tested whether the arched back posture in women is an indicator of sexual receptivity. Results showed that both men and women associated increases in the arch of the back with higher sexual receptivity in women. Study 2 predicted and confirmed that sexual receptivity is also perceived from non-standing postures, namely supine and quadruped poses. Study 3 tested the prediction that the perception of sexual receptivity is specific to the posture being adopted by women.

Conclusion

Collectively this research provides support for the sexual receptivity hypothesis of lordosis posture by showing that sexual receptivity is perceived by an increase in the arch of the back (Study 1), it is perceived as sexually receptive irrespective of the body posture (Study 2), and this is specific to women (Study 3).

Objective

A goal of behavioral neuroendocrinology is to understand how basal hormone levels relate to behavior. Studies of human participants sometimes measure self-reported personality traits, in addition to or instead of direct behavioral observation. Although personality traits often predict their respective behaviors, whether personality explains hormone-behavior relationships remains unclear.

Methods

We obtained data from eight previous studies (total N = 985) that examined baseline testosterone and cortisol as predictors of status-relevant behavior (competitiveness, dominance, risk-taking, aggression, affiliation, and social status). We tested whether the previously reported hormone-behavior relationships are mediated by self-reported personality traits (e.g., trait dominance, prestige, extraversion). As a secondary research question, we also tested whether trait dominance moderated the testosterone-behavior relationships.

Results

As expected, self-reported personality traits often predicted status-relevant behaviors, but there was little evidence that traits also correlated with basal testosterone or the testosterone × cortisol interaction. Across all eight studies, personality traits did not significantly mediate hormone-behavior relationships. Indeed, the effect sizes of the hormone-behavior relationships were robust to the inclusion of personality traits as covariates. Further, we did not find strong or consistent evidence that trait dominance moderates the testosterone-behavior association.

Conclusion

Results suggest that basal testosterone and cortisol predict status-related behavior independent of self-reported personality. We discuss how these results may have broader implications for the physiological mechanisms by which testosterone and cortisol influence behavior, a process that could be unconscious and automatic. We also discuss alternative explanations, limitations, and future directions.

Disgust is an emotion that regulates disease avoidance and reduces the likelihood of pathogenic infections. Existing research suggests a bidirectional relationship between disgust and mating, where disgust inhibits sexual behavior and sexual behavior inhibits disgust. In the current study, we investigated the role of individual differences and mating motivations on visual attention to pathogenic cues. Participants (N = 103) were randomly assigned to a mating prime or control condition, and they were asked to view images of pathogenic cues (i.e., rotten food, exposed cuts, bodily fluids) paired with their non-pathogenic counterparts. The findings showed no effect of mating prime on visual attention to pathogenic stimuli; however, dispositional mating strategies (SOI-R) were associated with attention to pathogenic stimuli. Individuals with unrestricted sociosexual orientations viewed pathogenic stimuli longer. The findings demonstrate that dispositional mating orientation is associated with greater attention to disgusting images, a link between pathogens and mating orientation that warrants further exploration.

Immunocompetence can influence an organism’s reproductive fitness, and thus presumably their desirability as a mate (i.e., mate value). In humans, the link between immunocompetence and mate value has found circumstantial support by way of both expressed mate preferences for healthy partners, and via preferences for attractive phenotypes that are ostensibly linked to immune functioning. We examined whether a biological marker of immunocompetence, salivary immunoglobulin A (sIgA), along with self-reported frequency and severity of symptoms of poor health predicted individuals’ reported mate value and mating behavior in a sample of 691 young adults. Our measures of immunocompetence (sIgA and symptoms of poor health) correlated significantly with one another, suggesting sIgA is a viable marker of general immune function in young adults. We then examined the independent contributions of these variables to mate value, controlling for age, sex, and body mass index (BMI). Results showed that sIgA (positively) and poor health (negatively) predicted mate value, but not lifetime number of sex partners or current romantic relationship status. These findings suggest that those with better health and immune function report being more desirable as mating partners but support past research showing null links to reported mating behavior. Together, these findings suggest that more comprehensive work on links between immunocompetence and mating is required.