Harald A. Euler

The Geographic Distribution of Big Five Personality Traits Patterns and Profiles of Human Self-Description Across 56 Nations

The Big Five Inventory (BFI) is a self-report measure designed to assess the high-order personality traits of Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness. As part of the International Sexuality Description Project, the BFI was translated from English into 28 languages and administered to 17,837 individuals from 56 nations. The resulting cross-cultural data set was used to address three main questions: Does the factor structure of the English BFI fully replicate across cultures? How valid are the BFI trait profiles of individual nations? And how are personality traits distributed throughout the world? The five-dimensional structure was robust across major regions of the world. Trait levels were related in predictable ways to self-esteem, sociosexuality, and national personality profiles. People from the geographic regions of South America and East Asia were significantly different in openness from those inhabiting other world regions. The discussion focuses on limitations of the current data set and important directions for future research.

Patterns and Universals of Adult Romantic Attachment Across 62 Cultural Regions Are Models of Self and of Other Pancultural Constructs

As part of the International Sexuality Description Project, a total of 17,804 participants from 62 cultural regions completedthe RelationshipQuestionnaire(RQ), a self-reportmeasure of adult romanticattachment. Correlational analyses within each culture suggested that the Model of Self and the Model of Other scales of the RQ were psychometrically valid within most cultures. Contrary to expectations, the Model of Self and Model of Other dimensions of the RQ did not underlie the four-category model of attachment in the same way across all cultures. Analyses of specific attachment styles revealed that secure romantic attachment was normative in 79% of cultures and that preoccupied romantic attachment was particularly prevalent in East Asian cultures. Finally, the romantic attachment profiles of individual nations were correlated with sociocultural indicators in ways that supported evolutionary theories of romantic attachment and basic human mating strategies.

How the brain repairs stuttering

Stuttering is a neurodevelopmental disorder associated with left inferior frontal structural anomalies. While children often recover, stuttering may also spontaneously disappear much later after years of dysfluency. These rare cases of unassisted recovery in adulthood provide a model of optimal brain repair outside the classical windows of developmental plasticity. Here we explore what distinguishes this type of recovery from less optimal repair modes, i.e. therapy-induced assisted recovery and attempted compensation in subjects who are still affected. We show that persistent stuttering is associated with mobilization of brain regions contralateral to the structural anomalies for compensation attempt. In contrast, the only neural landmark of optimal repair is activation of the left BA 47/12 in the orbitofrontal cortex, adjacent to a region where a white matter anomaly is observed in persistent stutterers, but normalized in recovered subjects. These findings show that late repair of neurodevelopmental stuttering follows the principles of contralateral and perianomalous reorganization.

Are men universally more dismissing than women? Gender differences in romantic attachment across 62 cultural regions

Gender differences in the dismissing form of adult romantic attachment were investigated as part of the International Sexuality Description Project - a survey study of 17,804 people from 62 cultural regions. Contrary to research findings previously reported in Western cultures, we found that men were not significantly more dismissing than women across all cultural regions. Gender differences in dismissing romantic attachment were evident in most cultures, but were typically only small to moderate in magnitude. Looking across cultures, the degree of gender differentiation in dismissing romantic attachment was predictably associated with sociocultural indicators. Generally, these associations supported evolutionary theories of romantic attachment, with smaller gender differences evident in cultures with high-stress and high-fertility reproductive environments. Social role theories of human sexuality received less support in that more progressive sex-role ideologies and national gender equity indexes were not cross-culturally linked as expected to smaller gender differences in dismissing romantic attachment.

Severity of dysfluency correlates with basal ganglia activity in persistent developmental stuttering

Previous studies suggest that anatomical anomalies [Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering. Neurology, 57, 207-215; Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., & Heilman, K. M. (2003). Atypical cerebral laterality in adults with persistent developmental stuttering. Neurology, 61, 1378-1385; Foundas, A. L., Bollich, A. M., Feldman, J., Corey, D. M., Hurley, M., & Lemen, L. C. et al., (2004). Aberrant auditory processing and atypical planum temporale in developmental stuttering. Neurology, 63, 1640-1646; Jancke, L., Hanggi, J., & Steinmetz, H. (2004). Morphological brain differences between adult stutterers and non-stutterers. BMC Neurology, 4, 23], in particular a reduction of the white matter anisotropy underlying the left sensorimotor cortex [Sommer, M., Koch, M. A., Paulus, W., Weiller, C., & Buchel, C. (2002). Disconnection of speech-relevant brain areas in persistent developmental stuttering. Lancet, 360, 380-383] could be at the origin of persistent developmental stuttering (PDS). Because neural connections between the motor cortex and basal ganglia are implicated in speech motor functions, PDS could also be associated with a dysfunction in basal ganglia activity [Alm, P. (2004). Stuttering and the basal ganglia circuits: a critical review of possible relations. Journal of Communication Disorders, 37, 325-369]. This fMRI study reports a correlation between severity of stuttering and activity in the basal ganglia and shows that this activity is modified by fluency shaping therapy through long-term therapy effects that reflect speech production improvement. A model of dysfunction in stuttering and possible repair modes is proposed that accommodates the data presented here and observations previously made by us and by others.

Evidence for compensation for stuttering by the right frontal operculum

There is recent evidence of focal alteration in fibre tracts underlying the left sensorimotor cortex in persistent developmental stuttering (PDS) [Lancet 360 (2002) 380]. If, as proposed, this anatomical abnormality is the cause of PDS, then overactivation in the right hemisphere seen with functional neuroimaging in stutterers may reflect a compensatory mechanism. To investigate this hypothesis, we performed two functional magnetic resonance imaging (fMRI) experiments. The first showed systematic activation of a single focus in the right frontal operculum (RFO) in PDS subjects during reading, which was not observed in controls. Responses in this region were negatively correlated with the severity of stuttering, suggesting compensation rather than primary dysfunction. Negative correlation was also observed during the baseline task that consisted in passive viewing of meaningless signs, indicating that RFO compensation acts independently of specific demands on motor speech output. The second experiment, that involved a covert semantic decision task, confirmed that RFO activation does not require overt utterances or motor output. In combination these findings suggest that the RFO serves a nonspecific compensatory role rather than one restricted to the final stages of speech production.

Psychological adaptation to human sperm competition

Abstract Sperm competition occurs when the sperm of two or more males simultaneously occupy the reproductive tract of a female and compete to fertilize an egg. We used a questionnaire to investigate psychological responses to the risk of sperm competition for 194 men in committed, sexual relationships in the United States and in Germany. As predicted, a man who spends a greater (relative to a man who spends a lesser) proportion of time apart from his partner since the couples last copulation reported (a) that his partner is more attractive, (b) that other men find his partner more attractive, (c) greater interest in copulating with his partner, and (d) that his partner is more sexually interested in him. All effects were independent of total time since the couples last copulation and the mans relationship satisfaction. Discussion addresses two failed predictions and directions for future work.

Relationship-Specific Closeness of Intergenerational Family Ties Findings from Evolutionary Psychology and Implications for Models of Cultural Transmission

Cross-generational cultural transmission is facilitated by affectional ties between cultural model and recipient. A theory of cultural transmission must therefore account for how and why affectional ties vary between different dyadic relationships. Findings on the tie strengths of several intergenerational kin dyads (grandparent- grandchild, grandparent-parent, aunt/uncle-niece/nephew) as rated by recipients of kin investment (adult grandchildren or nieces/nephews) are presented, based on several studies with altogether more than 3,000 participants between 16 and 80 years old. The relationship structures were dyad specific; asymmetrical with a tilt to the maternal side; robust; and predictable from reproductively relevant variables of the kinpersons involved, namely, sex-specific reproductive strategy, paternity uncertainty, and genetic closeness. Implications for the study of intrafamilial cultural transmission are discussed, with an emphasis on the importance of evolutionary theory for this research field.

Female coital orgasm and male attractiveness

Female coital orgasm may be an adaptation for preferentially retaining the sperm of males with “good genes.” One indicator of good genes may be physical attractiveness. Accordingly, R. Thornhill, S. W. Gangestad, and R. Comer (1995) found that women mated to more attractive men reported an orgasm during a greater proportion of copulations than did women mated to less attractive men. The current research replicates this finding, with several design variations. We collected self-report data from 388 women residing in the United States or in Germany. Results support the hypothesis that women mated to more attractive men are more likely to report an orgasm at the most recent copulation than are women mated to less attractive men, after statistically controlling for several key variables. Discussion addresses (a) the inability of the present research to specify the causal link between female orgasm and male attractiveness and (b) the proactive nature of female sexuality documented in recent research guided by an evolutionary perspective.

Effectiveness and Efficiency of a Universal Newborn Hearing Screening in Germany

The decision to mandate, finance, and implement a universal newborn hearing screening (UNHS) requires the evaluation of its therapy-directed benefit by comparing (1) a procedure employing a UNHS with (2) a targeted screening for at-risk babies for neonatal hearing disorders and (3) a procedure without systematic screening. In a cohort study the outcome of the UNHS program of Hessen in 2005 with 17,439 screened newborns was analyzed. Validity, effectiveness, and efficiency were evaluated and compared to a sample of 98 Hessian and 355 German children who were detected in 2005 as hearing-impaired but not by an UNHS. The UNHS group had a PASS rate of 97.0%. Forty-nine hearing-impaired children were diagnosed at a median age of 3.1 months and treated at a median age of 3.5 months. Corresponding values for the Hessian non-UNHS group were 17.8 and 21.0 months. For Germany the median age at diagnosis was 39.0 months. The age at therapy onset correlated negatively with parameters of speech/language and psychosocial development. A targeted screening would have resulted in a low sensitivity of 65.3%. Hence, a UNHS is the most effective way to an early therapy of neonatal hearing disorders with an optimal outcome.