Johannes Hönekopp

Meta-analysis of digit ratio 2D:4D shows greater sex difference in the right hand.

Our aims are, first, to describe the sex difference in the length ratio of the second and fourth digits (2D:4D), which likely reflects prenatal testosterone levels in humans. Second, to infer the loss of reliability observed in 2D:4D based on self‐measured finger lengths.

Digit ratio 2D:4D in relation to autism spectrum disorders, empathizing, and systemizing: a quantitative review.

Prenatal testosterone (PT) effects have been proposed to increase systemizing (the drive to understand lawful input–output relationships), to decrease empathizing (the drive to understand others), and to cause autism via hypermasculinization of the brain. Digit ratio 2D:4D is a putative marker of PT effects in humans. An online study (n = 1896) into the relationship between the Reading the Mind in the Eyes Test (a widely used measure of empathizing) and self‐measured 2D:4D in a nonclinical sample is reported. No evidence for a link between empathizing and 2D:4D in either females or males emerged. Further, three meta‐analyses are presented that look into the relationships of 2D:4D with autism spectrum disorder (ASD), systemizing, and empathizing. 2D:4D was substantially lower (more masculine) in ASD‐affected individuals than in normal controls (d = −0.58, P < 0.001). However, 2D:4D was found to be virtually unrelated to systemizing and empathizing in normal adults. The results support the idea that high PT is a risk factor for autism, but they challenge the view that PT substantially contributes to sex differences in systemizing and empathizing. Possibly, this pattern reflects an interaction effect, whereby PT drives ASD characteristic changes only in brains with a specific damage. Autism Res 2012, 5: 221–230.

Male dance moves that catch a woman's eye

Male movements serve as courtship signals in many animal species, and may honestly reflect the genotypic and/or phenotypic quality of the individual. Attractive human dance moves, particularly those of males, have been reported to show associations with measures of physical strength, prenatal androgenization and symmetry. Here we use advanced three-dimensional motion-capture technology to identify possible biomechanical differences between womens perceptions of ‘good’ and ‘bad’ male dancers. Nineteen males were recorded using the ‘Vicon’ motion-capture system while dancing to a basic rhythm; controlled stimuli in the form of avatars were then created in the form of 15 s video clips, and rated by 39 females for dance quality. Initial analyses showed that 11 movement variables were significantly positively correlated with perceived dance quality. Linear regression subsequently revealed that three movement measures were key predictors of dance quality; these were variability and amplitude of movements of the neck and trunk, and speed of movements of the right knee. In summary, we have identified specific movements within mens dance that influence womens perceptions of dancing ability. We suggest that such movements may form honest signals of male quality in terms of health, vigour or strength, though this remains to be confirmed.

No Evidence that 2D:4D is Related to the Number of CAG Repeats in the Androgen Receptor Gene

The length ratio of the second to the fourth digit (2D:4D) is a putative marker of prenatal testosterone (T) effects. The number of CAG repeats (CAGn) in the AR gene is negatively correlated with T sensitivity in vitro. Results regarding the relationship between 2D:4D and CAGn are mixed but have featured prominently in arguments for and against the validity of 2D:4D. Here, I present random-effects meta-analyses on 14 relevant samples with altogether 1904 subjects. Results were homogeneous across studies. Even liberal estimates (upper limit of the 95% CI) were close to zero and therefore suggested no substantial relationship of CAGn with either right-hand 2D:4D, left-hand 2D:4D, or the difference between the two. However, closer analysis of the effects of CAGn on T dependent gene activation in vitro and of relationships between CAGn and T dependent phenotypic characteristics suggest that normal variability of CAGn has mostly no, very small, or inconsistent effects. Therefore, the lack of a clear association between CAGn and 2D:4D has no negative implications for the latter’s validity as a marker of prenatal T effects.

Progressive stage transition does mean getting better: a further test of the Transtheoretical Model in recovery from alcohol problems.

AIMS To test two central assumptions of the Transtheoretical Model (TTM) regarding recovery from alcohol problems: (i) individuals making a forward transition from pre-action to action stages will show greater drinking improvements than those remaining in pre-action stages; and (ii) individuals remaining in pre-action stages will not demonstrate improvements in drinking outcomes. DESIGN AND SETTING Large, multi-centre, randomized controlled trial of treatment for alcohol problems [United Kingdom Alcohol Treatment Trial (UKATT)]. MEASUREMENTS Stage of change, drinks per drinking day and percentage days abstinent at baseline, 3- and 12-month follow-ups. FINDINGS In support of TTM assumption 1, improvements in drinking outcomes were consistently greater among clients who showed a forward stage transition (Cohens d = 0.68) than among those who did not (d = 0.10). Two tests of assumption 2 showed a significant improvement in drinking outcomes in non-transition groups, inconsistent with the TTM; one test showed a significant deterioration and the other showed equivalent drinking outcomes across time. An explanation is offered as to why, under the relevant assumption of the TTM, clients in non-transition groups showed small changes in drinking outcomes. CONCLUSIONS In contrast to a previous study by Callaghan and colleagues, our findings largely support the TTM account of recovery from alcohol problems in treatment. The discrepancy can be explained by the use in our study of a more reliable and valid method for assigning stage of change.

Male body movements as possible cues to physical strength: A biomechanical analysis

Comparative research suggests that male courtship displays signal condition‐dependent traits tofemales; these displays might also provide cues to potential male competitors. Although some associations betweenhuman movements and physical/behavioral qualities have been found, such research has typically only been conducted from a perspective of female mate choice. Here, using advanced motion capture and biomechanical analyses, we examine the extent to which male dancing provides cues about the dancers physical qualities to both males and females.

A revised edition of the readiness to change questionnaire (treatment version)

The UK Alcohol Treatment Trial provided an opportunity to examine the factor structure of the Readiness to Change Questionnaire–Treatment Version (RCQ[TV]) in a large sample (N = 742) of individuals in treatment for alcohol problems who were given the RCQ[TV] at baseline, 3-months and 12-months follow-up. Confirmatory factor analysis of the previously reported factor structure (5 items for each of Precontemplation, Contemplation and Action scales) resulted in a relatively poor fit to the data. Removal of one item from each of the scales resulted in a 12-item instrument for which goodness-of-fit indices were improved, without loss of internal consistency of the three scales, on all three measurement occasions. Inspection of relationships between stage allocation by the new instrument and negative alcohol outcome expectancies provided evidence of improved construct validity for the revised edition of the RCQ[TV]. There was also a strong relationship between stage allocation at 3-months follow-up and outcome of treatment at 12 months. The revised edition of the RCQ[TV] offers researchers and clinicians a shorter and improved measurement of stage of change in the alcohol treatment population.

Pre-adjustment of adult attachment style to extrinsic risk levels via early attachment style is neither specific, nor reliable, nor effective, and is thus not an adaptation

The mechanism proposed by Del Giudice by which adult attachment style is adapted to the extrinsic risk in the local environment via attachment style during the early years does not fulfill important criteria of an adaptation. The proposed mechanism is neither specific, nor developmentally reliable, nor effective. Therefore, it should not be considered an adaptation.

Digit Ratio (2D:4D) and Male Facial Attractiveness: New Data and a Meta-Analysis:

Digit ratio (2D:4D) appears to correlate negatively with prenatal testosterone (T) effects in humans. As T probably increases facial masculinity, which in turn might be positively related to male facial attractiveness, a number of studies have looked into the relationship between 2D:4D and male facial attractiveness, showing equivocal results. Here, I present the largest and third largest samples so far, which investigate the relationship between 2D:4D and male facial attractiveness in adolescents (n = 115) and young men (n = 80). I then present random-effects meta-analyses of the available data (seven to eight samples, overall n = 362 to 469). These showed small (r ≈ -.09), statistically non-significant relationships between 2D:4D measures and male facial attractiveness. Thus, 2D:4D studies offer no convincing evidence at present that prenatal T has a positive effect on male facial attractiveness. However, a consideration of confidence intervals shows that, at present, a theoretically meaningful relationship between 2D:4D and male facial attractiveness cannot be ruled out either.