From DNA Repair to Social Minds:

 The Root of Sex-dichotomous Psychology and Behaviour

Steve Moxon, 2014

Presentation for the conference From DNA To Social MindsUniversity of York, June/July 2014.

THE fundamental problem for biological systems

Accumulated replication error: gene mutation and adverse recombination.

[This is the issue with any form of iterated replication, eg, photocopying.]

Sex actually exacerbates deleterious genetic loading through the more even distribution and dilution it provides, thus hindering purging; necessitating a complementary, additional process to sex per se to deal with this.

This essential mechanism has profound implications foundational to social system.

Male-'quarantined' purging

With the female the limiting factor in reproduction, then any extra purging process in effect has to be confined to the male half of the lineage, which is what has been identified as the 'genetic filter' (Atmar) / 'mutational cleanser' (West-Eberhard) key male function.

With males 'expendable', all but those males with exceptionally low loadings of 'bad genes', in various ways can be absolutely or relatively restricted from reproducing. 

Not only does this not impede overall reproduction of the reproductive group, but has the benefit of greater reproductive efficiency – apparently the trajectory of evolution.

The key mechanism

Males endogenously driven to intra-sexual competition are adapted to neurally register 'winner' and/or 'loser' effects, thereby to form a self-organised rank order according to genetic quality; enabling accurate, efficient mate choice by females.

Hence the basis of mate value for males in status, in contrast to that for females of fertility (youth/beauty).

[The male 'genetic filter' function is a fuller explanation than hitherto has been available for the ferocity of male intra-sexual competitiveness (and the lack of a female equivalent), & why competition is never inter-sexual (any ostensibly so is deference/display).]

The associated role of male stress response

Mechanism re stress recently has been shown to be sex-dichotomous (there are major qualitative distinctions, and where difference is quantitative the data is non-overlapping).

Stress in males is 'manufactured' – endogenous or channelled – so as to spur males to mutually compete.

By contrast, for females, stress in essence is a problem to be ameliorated (related to this is theory that stress drives females to tend-and-befriend – not fight-or-fight).

Thus is explained the key feature of sociality

Modes of association from toddler age essentially are same-sex and sex-dichotomous.

Boys (and men) establish male-male wholly inclusive hierarchy – dominance and/or prestige based; transitive, and often linear.

By contrast, girls (and women) form female-female exclusive dyad-based individual chains of association extending out from family: a 'personal network'.

[Presumably this functions to provide mutual support in child-rearing, and for gossip (to exchange reliable quality information on mate-values of specific males).]

Correspondingly, in-group is also sex-dichotomous

Through the whole-group-centred inclusivity of hierarchy, boys/men readily identify with symbolic grouping (eg; everyone in a year-group, club, or workplace – including females)

In line with 'personal-networking', girls'/women's in-grouping excludes most others in cutting across any symbolic grouping and featuring a very strong same-sex preference.

[Presumably, as well as to facilitate child support and 'gossip', this also functions to improve accessibility to high-mate-value males, while inhibiting this for less fertile rivals.]

An invalid usual objection (1):

Doesn't culture trump biology?

No, 'bottom-up' biological explanation is not rivalled or clouded by any 'top-down'.

Quite the reverse.

The cognitive facility to produce culture self-evidently must have evolved to function to feed back to fine-tune & reinforce the underlying biology. 

Therefore culture never more than superficially develops along any novel tangent.

Instead, ever more complex cognitive ability serves to ever better express the genome.

The 'niche' humans construct for themselves constitutes 'extended phenotype' and is itself very much part of biology.

Otherwise, in effect we would be 'transcending' ourselves. 

[See (the philosopher) John Gray's censure of Dawkins, Pinker and Dennett on the nonsensical notion that we can 'transcend our genes'.]

So the supposed hopeless confounding of underlying biology by cultural superstructure is not the case.

Rather, what is common across cultural variation is a useful window on biology.

The issue has been the lack of understanding of the underlying biology sufficient to be able to identify it.

An invalid usual objection (2):

Isn't 'group selection' entailed?

Re apparent cooperation, there is no need to invoke multi-level ('group') selection; either naïve or sophisticated (as re-formulated by Novak, Tarnita & Wilson, 2010).

Instead, a proper understanding of 'kin selection' reveals co-operation evolving through the interplay of genetic and population structuring (Lion, Jansen & Day, 2011). 

Independently, Powers, Penn & Watson (2011) arrived at a similar model.

Another perspective is that lower individual fitness in the short-term can be more than compensated by higher fitness in the long-term, through the exploitation of an aspect of the selection process itself in 'lineage selection' (Nunney, 1999).

With a number of mathematically equivalent rival models, it is more a question of which is preferred philosophically than which is empirically justified.

Theory, then, is no obstacle to positing fitness-enhancing apparently group-level phenomena.


* Moxon SP (2012) The Origin of the Sexual Divide in the Genetic Filter Function --
Male Disadvantage and Why it is Not Perceived
New Male Studies 1(3) 96-124
[See the referenced discussion here re sex exacerbating accumulation of gene replication error]
* Atmar W (1991) On the role of males.
Animal Behaviour 41(2) 195-205
* West-Eberhard MJ (2005) The maintenance of sex as a developmental trap due to sexual selection. Quarterly Review of Biology 80(1)
* Moxon SP (2009) Dominance as adaptive stressing and ranking of males,
serving to allocate reproduction by differential self-suppressed fertility:
Towards a fully biological understanding of social systems.
Medical Hypotheses 73(1) 5-14
* Wang J, Korczykowski M, Rao H, Fan Y, Pluta J, Gur RC et al (2007)
Gender difference in neural response to psychological stress.
Social Cognitive and Affective Neuroscience 227-39
* Moxon SP (2008) The Woman Racket:
The New Science Explaining How the Sexes Relate at Work, at Play and in Society.
Imprint Academic
* Maddox W & Brewer M (2005) Gender differences in the relational and collective bases for trust. Group Processes Intergroup Relations 8(2) 159-171
* Yamagishi T & Mifune N (2009) Social exchange and solidarity: In-group love or out-group hate? Evolution and Human Behavior 30 229–237
* Goodwin S & Rudman L (2004) Gender differences in automatic in-group bias:
Why do women like women more than men like men?
Social Psychology 87(4) 494-509
* Novak MA, Tarnita CE & Wilson EO (2010) The evolution of eusociality. Nature 466 1057-1062
* Lion S, Jansen VAA & Day T (2011) Evolution in structured populations:
Beyond the kin versus group debate.
Trends in Ecology and Evolution 26(4) 193
* Powers ST, Penn AS & Watson RA (2011) The concurrent evolution of cooperation and the population structures that support it.
Evolution 65(6) 1527-1543
* Nunney L (1999) Lineage selection: natural selection for long-term benefit.
In Keller (ed) Levels of Selection in Evolution 238-252
* Moxon SP (2010) Culture is biology: why we cannot transcend out genes – or ourselves.
Politics & Culture On-line symposium 'How Is Culture Biological?' 
* Gray J (2007) Black Mass: Apocalyptic Religion and the Death of Utopia. Allen Lane

Further information

See: Moxon SP (2012) The Origin of the Sexual Divide in the Genetic Filter Function --
Male Disadvantage and Why it is Not Perceived. New Male Studies 1(3) 96-124
This and other related journal-published papers are available in full at;
as are info/links re books published by Imprint Academic.
Steve Moxon is an independent (non-affiliated) cross-disciplinary researcher/writer 
re the biological roots of human sociality, with a particular interest in the sexes.
Contact: Flat 11, 589 Crookesmoor Road, Broomhill, Sheffield S10 1BJ [UK]    0114 4384105  /  07981 227540