Objective: Neurological disorders can be mis-diagnosed as psychiatric ones when the psychiatric symptoms are the predominant. This is often the case of pedophilia emerging as a symptom of brain insult (i.e. acquired pedophilia). The aim of this research is to identify a behavioral profile that might help clinicians and psychiatric consultants to identify defendants whose pedophilia is more likely to be the consequence of a neurological disorder.Methods: Cluster hierarchical analysis on variables identified through a systematic review of the literature on cases of acquired pedophilia was applied to a new dataset including 66 italian closed cases of pedophilia. Stepwise regression analyses were carried out to further analyze the differences between the clusters identified in the cluster analysis. Results:The sample was partitioned into two large clusters. Individuals with ascertained acquired pedophilia were grouped together. The two clusters widely differed for the prevalence of red flags (2.14±0.79 vs 4.96±0.93, p<0.001). Regression analysis provided a robust model that included the three most significant red flags that, together, explain over 64.5% of the variance (absence of masking, spontaneous confession and offenders older age).Conclusions: An organic origin for pedophilia should be suspected if the red flags are present in a defendant charged with pedophilia: an in depth trans-disciplinary neuroscientific investigation is advocated. The behavioral profile identified might help to provide a proper assessment of defendants and might help judges to reach an informed decision on the defendant mens rea, reducing controversies and avoiding to punish people who need medical treatment.

Pedophilia is a disorder of public concern because of its association with child sexual offense and recidivism. Previous neuroimaging studies of potential brain abnormalities underlying pedophilic behavior, either in idiopathic or acquired (i.e., emerging following brain damages) pedophilia, led to inconsistent results. This study sought to explore the neural underpinnings of pedophilic behavior and to determine the extent to which brain alterations may be related to distinct psychopathological features in pedophilia. To this aim, we run a coordinate based meta-analysis on previously published papers reporting whole brain analysis and a lesion network analysis, using brain lesions as seeds in a resting state connectivity analysis. The behavioral profiling approach was applied to link identified regions with the corresponding psychological processes. While no consistent neuroanatomical alterations were identified in idiopathic pedophilia, the current results support that all the lesions causing acquired pedophilia are localized within a shared resting state network that included posterior midlines structures, right inferior temporal gyrus and bilateral orbitofrontal cortex. These regions are associated with action inhibition and social cognition, abilities that are consistently and severely impaired in acquired pedophiles. This study suggests that idiopathic and acquired pedophilia may be two distinct disorders, in line with their distinctive clinical features, including age of onset, reversibility and modus operandi. Understanding the neurobiological underpinnings of pedophilic behavior may contribute to a more comprehensive characterization of these individuals on a clinical ground, a pivotal step forward for the development of more efficient therapeutic rehabilitation strategies.

Sexual conflict likely plays a crucial role in the origin and maintenance of homosexuality in our species. Although environmental factors are known to affect human homosexual (HS) preference, sibling concordances and population patterns related to HS indicate that genetic components are also influencing this trait in humans. We argue that multilocus, partially Xlinked genetic factors undergoing sexually antagonistic selection that promote maternal female fecundity at the cost of occasional male offspring homosexuality are the best candidates capable of explaining the frequency, familial clustering, and pedigree asymmetries observed in HS male proband families. This establishes male HS as a paradigmatic example of sexual conflict in human biology. HS in females, on the other hand, is currently a more elusive phenomenon from both the empirical and theoretical standpoints because of its fluidity and marked environmental influence. Genetic and epigenetic mechanisms, the latter involving sexually antagonistic components, have been hypothesized for the propagation and maintenance of female HS in the population. However, further data are needed to truly clarify the evolutionary dynamics of this trait. Sexual conflict, the general theme of this collection, has emerged in the last decades as a main research topic in evolutionary biology. Its possible ubiquity and key role have become clear in many phenomena, from speciation to genetic diversity maintenance in populations, sexual phenotypic dimorphism, asymmetric mating and parenting strategies, antagonistic coevolution, and others (Bonduriansky and Chenoweth 2009;Rice et al. 2013; see also Gavrilets 2014). A most interesting example of sexual conflict is given by homosexual (HS) behavior and mate preference in humans, a topic whose societal impact is widely felt at present.Homosexuality is not confined just to our species, but is also occasionally present in numerous animals (Bagemihl 1999;Sommer and Vasey 2006), with permanent, long-term samesex pair bonding having been reported in some birds and ungulates (Bagemihl 1999;Ngun et al. 2011). The presence of not solely sporadic and opportunistic HS behavior has also been observed in nonhuman primates, which suggests our hominid ancestry might also have had HS individuals (Vasey 1995).The main evolutionary questions about HS in our species do not concern occasional HS behavior, which might have, in various con-

A growing number of researchers suggest that female homosexuality is at least in part influenced by genetic factors. Unlike for male homosexuality, few familial studies have attempted to explore maintenance of this apparently fitness-detrimental trait in the population. Using multiple recruitment methods, we explored fecundity and sexual orientation within the pedigrees of 1,458 adult female respondents. We compared 487 homosexual and 163 bisexual with 808 heterosexual females and 30,203 of their relatives. Our data suggest that the direct fitness of homosexual females is four times lower than the direct fitness of heterosexual females of corresponding ages. The prevalence of nonheterosexuality within the homosexual female respondents' families (2.83%) appear to be more than four times higher than the basal prevalence in the Italian population (0.63%). Pedigree size and relative fecundity in both the paternal and maternal sides of the homosexual women's families were significantly higher than in the heterosexuals' families. If confirmed, the relative average fecundity increase within the family seems to offset the loss in fitness due to the low direct fitness of homosexual females. Therefore, the balanced fecundity in the homosexual females' families may allow the trait to be maintained at a low-frequency equilibrium in the population.

Objective: Pedophilia is a disorder of public concern because of its association with child sexual offense and recidivism. Previous neuroimaging studies identified inconsistent brain abnormalities underlying pedophilic behavior both in idiopathic and acquired (i.e., emerging following brain damage) pedophilia. This study sought to explore the neural underpinnings of pedophilic behavior and to determine the extent to which brain alterations may be related to distinct psychopathological features in pedophilia. Methods: A coordinate based meta-analysis on previously published papers reporting whole brain analysis and a lesion network analysis using brain lesions as seeds in a resting state connectivity analysis were run to investigate the presence of consistent neural basis of idiopathic and acquired pedophilic behavior, respectively. The behavioral profiling approach was applied to link identified regions with corresponding psychological processes. Results: While no consistent neuroanatomical alterations have been identified in idiopathic pedophilia, the current results support that all the lesions causing acquired pedophilia localized to a shared resting state network including posterior midlines structures, right inferior temporal gyrus and bilateral orbitofrontal cortex. These regions are associated with action inhibition and social cognition, abilities that are consistently described as severely impaired in acquired pedophiles. Conclusions: This study suggests that idiopathic and acquired pedophilia may be two distinct disorders, in line with their distinctive clinical features, including age of onset, reversibility and modus operandi. Understanding the neurobiological underpinnings of pedophilic behavior may contribute to a more comprehensive characterization of these individuals on a clinical ground and to develop more efficient therapeutic rehabilitation strategies.