MyMedR

Displaying all 9 publications

Abstract:

Sort:

Criminality and the 2D:4D ratio: testing the prenatal androgen hypothesis

Ellis L, Hoskin AW

Int J Offender Ther Comp Criminol, 2015 Mar;59(3):295-312.
PMID: 24013770 DOI: 10.1177/0306624X13503813

A decade old theory hypothesizes that brain exposure to androgens promotes involvement in criminal behavior. General support for this hypothesis has been provided by studies of postpubertal circulating levels of testosterone, at least among males. However, the theory also predicts that for both genders, prenatal androgens will be positively correlated with persistent offending, an idea for which no evidence currently exists. The present study used an indirect measure of prenatal androgen exposure-the relative length of the second and fourth fingers of the right hand (r2D:4D)-to test the hypothesis that elevated prenatal androgens promote criminal tendencies later in life for males and females. Questionnaires were administered to 2,059 college students in Malaysia and 1,291 college students in the United States. Respondents reported their r2D:4D relative finger lengths along with involvement in 13 categories of delinquent and criminal acts. Statistically significant correlations between the commission of most types of offenses and r2D:4D ratios were found for males and females even after controlling for age. It is concluded that high exposure to androgens during prenatal development contributes to most forms of offending following the onset of puberty.
Delinquency, androgens, and the family: a test of evolutionary neuroandrogenic theory

Ellis L, Das S

Int J Offender Ther Comp Criminol, 2013 Aug;57(8):966-84.
PMID: 22514238 DOI: 10.1177/0306624X12440564

There is little doubt that family factors can influence involvement in delinquency, although the full nature and extent of their influences remain unclear. In recent decades, testosterone has been increasingly implicated as a contributor to adolescent offending. The present study sought to determine whether two important types of familial factors--parental socioeconomic status and amicable parent-child relationships--are interacting with testosterone (and possibly other androgens) to affect delinquency. A large sample of North American college students self-reported their involvement in eight categories of delinquency along with self-ratings of various androgen-promoted traits (e.g., muscularity and low-deep voice), parental social status, and the quality of the relationships they had with parents. In both sexes, parent-child relationships and androgens were significantly associated with delinquency but parental social status was not. Factor analysis revealed that the authors' measures of all four categories of variables exhibited strong loadings onto their respective factors. Androgens and amicable parent-child relationships were associated with delinquency but parental social status was not. About one third of the influence of parent-child relationships on delinquency appeared to be attributable to androgens. Findings are discussed from the perspective of the evolutionary neuroandrogenic theory of delinquent and criminal behavior.
Sex differences in smiling and other photographed traits: a theoretical assessment

Ellis L, Das S

J Biosoc Sci, 2011 May;43(3):345-51.
PMID: 21134308 DOI: 10.1017/S0021932010000659

Many studies have shown that females smile more than males do in social situations. The present study extends this research by examining a large sample of high school yearbook photographs. In addition to assessing the degree of smiling, ratings were obtained of the following traits for each photograph: hair length, hair colour, masculine-feminine appearance and physical attractiveness. Results reconfirmed earlier research showing that females smile more than males do while they are being photographed. Other findings were that smiling was positively correlated with hair length, femininity and physical attractiveness for females but not for males. When a multivariate analysis was performed, none of these traits predicted smiling in males, and only femininity was significant in predicting smiling in females. Although social learning theories of smiling can account for some of these findings, a recently proposed neurohormonal theory seems to best explain why femininity is related to smiling in females but not in males.
Putative Androgen Exposure and Sexual Orientation: Cross-Cultural Evidence Suggesting a Modified Neurohormonal Theory

Ellis L, Lykins A, Hoskin A, Ratnasingam M

J Sex Med, 2015 Dec;12(12):2364-77.
PMID: 26663858 DOI: 10.1111/jsm.13070

According to neurohormonal theory, prenatal androgens are key determinants of sexual orientation. As a reputed marker for prenatal androgens, the 2D:4D finger length ratio has been used in more than a dozen studies to test the hypothesis that prenatal androgens influence sexual orientation. Findings have been very inconsistent.
Maternal smoking during pregnancy and self-reported delinquency by offspring

Ellis L, Widmayer A, Das S

Crim Behav Ment Health, 2012 Dec;22(5):325-35.
PMID: 22696101 DOI: 10.1002/cbm.1828

BACKGROUND: Several studies have reported significant positive correlations between smoking during pregnancy by mothers and the involvement of their offspring in criminal/delinquent behaviour later in life, but these findings have been described as modest and the criminality based on official conviction statistics.
AIMS: We sought to verify this relationship and probe for more details on the basis of self-reported offending among college students.
METHODS: Independently completed questionnaires were collected from 6332 students and their mothers. The students provided information about their delinquent acts, if any, according to eight categories. Their mothers provided retrospective reports of their smoking habits, if any, during pregnancy.
FINDINGS: Mothers who recalled having smoked during pregnancy were significantly more likely than non-smoking mothers to have offspring who self-reported engaging in some types of delinquency. This relationship was more evident for female offspring than for male offspring and was most pronounced for illegal drug use by the offspring. There was, however, no relationship between offspring offending and estimated number of cigarettes smoked by mothers, month of pregnancy when smoked or consistency of smoking throughout pregnancy.
CONCLUSION: Overall, our study confirms that maternal smoking during pregnancy is associated with offspring involvement in delinquency, but the lack of critical timing or dose-response relationships between maternal smoking and later offspring delinquency cast doubt on the possibility that the associations are due to teratogenic effects of tobacco smoke.
Study site: college students at 20 US and two Canadian universities
Handedness, sexual orientation, and somatic markers for prenatal androgens: Are southpaws really that gay?

Ellis L, Skorska MN, Bogaert AF

Laterality, 2017 Mar;22(2):157-180.
PMID: 26932806 DOI: 10.1080/1357650X.2016.1151024

BACKGROUND: Some evidence suggests that prenatal androgens influence both handedness and sexual orientation. This study sought to clarify how androgens, handedness, and sexual orientation are interrelated.
METHODS: Data were obtained from large samples of students enrolled at universities in Malaysia and the US, including self-reported information on handedness, sexual orientation, and five somatic markers of prenatal androgen exposure (2D:4D, height, strength, muscularity, and athletic ability). Factor analysis of these somatic markers yielded two factors: a muscular coordination and a bone growth factor.
RESULTS: In women, but not in men, ambidextrousness was more prevalent among those with homosexual tendencies. Modest and often complex associations were found between the androgen factors and handedness. Clear links between the androgen factors and sexual orientation were found, especially for muscular coordination. For males and females, intermediate sex-typical androgen exposure was associated with heterosexual preferences.
CONCLUSIONS: Ambidextrousness appears to be somewhat more common among females with homosexual tendencies, but left-handedness is nearly as strongly associated with heterosexual preferences, particularly in males, as is right-handedness. Factors indicative of prenatal androgen exposure are associated with sexual orientation in theoretically predictable ways, especially for muscular coordination, but associations between prenatal androgens and handedness are complex.
Self-Reported Offending in the United States and Malaysia: Does East Meet West?

Hartley RD, Ellis L, Hoskin A

Int J Offender Ther Comp Criminol, 2021 Jul;65(9):999-1028.
PMID: 31672057 DOI: 10.1177/0306624X19883753

To date, international comparisons of self-reported crime have been mostly limited to Western countries. The current study explores offending for large samples of university students in Malaysia (N = 2,058) and the United States (N = 2,511), and utilizes measures of social bond theory to test its predictive utility cross-nationally. The descriptive results reveal that for both males and females, offending rates were substantially higher in the United States, often 3 to 4 times higher. Rare events logistic regression results reveal not only some support for our measures of the social bond constructs in both countries but also that there are significant cross-country differences in the correlates of offending. Partitioned regression models suggest these differences vary considerably by type of crime, and that some of the significant correlates of offending are similar cross-nationally but that unique predictors emerge by country dependent on the offense in question. Offending in the U.S. sample appears to be more closely linked to breakdowns in family structure (parental divorce, single parenthood), whereas for the Malaysian sample, parental income and respondent's education level seem to be more closely linked to offending. The current study provides one of just a few comparative studies between a Western country and an Asian country based on self-reported data. Such data can provide a useful cross-check of international comparisons based on official data. Methodologically, implications are that the self-report survey method continues to be a fruitful avenue for exploration of cross-national offending.
The androgen receptor gene and criminal offending: Evidence derived from international data

Ellis L, Hoskin A, Buker NH

Early Hum Dev, 2024 Sep 03;198:106113.
PMID: 39260075 DOI: 10.1016/j.earlhumdev.2024.106113

Beginning early in fetal development, the androgen receptor (AR) gene helps regulate bodily exposure to testosterone. Most studies of individuals have found an inverse correlation between the number of CAG repeats on this gene and serious forms of physical aggression. This two-phased study was primarily undertaken to determine if a link between AR CAGn and physical aggression also exists at an ecological level of analysis. To make this assessment, we first conducted a bivariate analysis of the average number of AR CAG repeats for a large number of countries and the rates of crime victimization in those same countries. Except for motor vehicle theft, as the national average number of CAG repeats increased, crime victimization rates decreased. This inverse relationship was especially strong for violent offenses. In the second phase of this study, we sought to determine if per capita gross domestic product, pathogen prevalence, and average intelligence might be mediating some of the AR CAG repeats-criminality relationship. Mediation analysis analysis indicated that, once gross domestic product and pathogenic prevalence were controlled, average intelligence was able to eliminate most of the links between CAG repeats and crime victimization rates, especially in the case of violent offenses. These findings suggest that the AR gene is not influencing criminality primarily by altering testosterone brain exposure (as we suspected). Instead, it may affect criminality mainly by affecting cognitive ability. In fact, once average national intelligence is included in the mediation analysis model, direct relationships between CAG repeats and measures of homicide, assault, and robbery were no longer statistically significant. Findings from this two-phased study point toward the AR gene as having multiple effects on brain functioning, particularly regarding intellectual development as hypothesized by Manning [62]. Replication is obviously needed.
General Theory versus ENA Theory: Comparing Their Predictive Accuracy and Scope

Ellis L, Hoskin A, Hartley R, Walsh A, Widmayer A, Ratnasingam M

Int J Offender Ther Comp Criminol, 2015 Dec;59(13):1429-58.
PMID: 25063685 DOI: 10.1177/0306624X14543263

General theory attributes criminal behavior primarily to low self-control, whereas evolutionary neuroandrogenic (ENA) theory envisions criminality as being a crude form of status-striving promoted by high brain exposure to androgens. General theory predicts that self-control will be negatively correlated with risk-taking, while ENA theory implies that these two variables should actually be positively correlated. According to ENA theory, traits such as pain tolerance and muscularity will be positively associated with risk-taking and criminality while general theory makes no predictions concerning these relationships. Data from Malaysia and the United States are used to test 10 hypotheses derived from one or both of these theories. As predicted by both theories, risk-taking was positively correlated with criminality in both countries. However, contrary to general theory and consistent with ENA theory, the correlation between self-control and risk-taking was positive in both countries. General theory's prediction of an inverse correlation between low self-control and criminality was largely supported by the U.S. data but only weakly supported by the Malaysian data. ENA theory's predictions of positive correlations between pain tolerance, muscularity, and offending were largely confirmed. For the 10 hypotheses tested, ENA theory surpassed general theory in predictive scope and accuracy.