The nature of the mechanisms underlying observed sex differences in human behaviour continues to be debated.
This review concentrates on the thesis that genes on the sex chromosomes other than those directly controlling sex determination, and whose functions are, at least in part, independent from hormonal influences, play a significant role in determining gender differences in behaviour. To provide an adequate basis for examining this issue, the current understanding of the nature of sex determination, differences in behaviour and the influences of sex hormones are evaluated. The possible contribution to behavioural differences of those X-linked genes which escape inactivation, or which may be subjected to imprinting, is discussed. The review concludes with a summary of the genetic basis for two sexually disparate types of behaviour.
It opens with gold;
That human males and females tend to behave differently is an undeniable fact, and indeed a welcome one.
The importance of sex differences in the brain and behaviour is indisputable. It forms the basis for differences in risk across a range of neurological and psychiatric disorders, as well as gender roles within society. The classical approach to investigating sex differences primarily involves comparisons between males and females. While informative for characterizing the wide array of sexually dimorphic traits, straight comparisons are insufficient to elucidate specific molecular contributions due to the multiplicity of confounding factors. Discrete genetic polymorphisms can be used to investigate variance in these traits due to sex-related molecular factors independent of confounds of sex.
This thesis applies candidate genetics to understand the specific contributions of molecular components of the sex hormone pathways to sexual dimorphism in brain structure, personality and cognition. A cohort of 384 individuals were recruited to undergo MRI brain scans, cognitive and personality testing. They also provided blood samples for candidate genotyping in polymorphisms in genes for the androgen receptor, oestrogen receptors, progesterone receptor and aromatase enzyme that converts testosterone to oestrogen. Voxel-based morphometry was used to characterise regional differences in brain volume accounted for by these polymorphisms and the relationship to sex differences in brain volume. Diffusion tensor imaging was then used to determine variation in white matter integrity and structural connectivity due to these polymorphisms. Sex differences in personality and cognition are further investigated in terms of correlations with the polymorphisms and brain structure. Finally an endophenotype approach was used to investigate differential risk for conditions such as Alzheimer’s disease and depression between sexes through related brain and personality-based traits. The neural and molecular genetic mechanisms underlying this risk are inferred from correlations with brain-based measures and genotype. The strengths and weaknesses of this approach and the scientific implications of this work to gender research are discussed.
At this point, anyone who denies biological sex differences in plainly anti-science.
The Government considers that now is an appropriate time to review the EU level rules with a view to modernisation and ensuring they are fit for purpose in the EU of today. The rules have evolved beyond the original scope as the EU has evolved and the interaction between rules on residence and social security coordination becoming increasingly complex. This complexity has led to an increasing number of challenges through the ECJ, creating uncertainty and, in the majority of cases, weakening the ability of Member States to determine how their systems operate. These problems are magnified by the fact that the EU of today is very different to when the rules were created. There are many more Member States and much greater diversity in how their social security systems operate. Migration patterns have also changed significantly, with much more migration than in the past, including more migration of non-working people including jobseekers. Without reform, legitimate public concern about how EU migrants access social security in other Member States is likely to significantly undermine support for the principle of free movement.~ 32.1, p57