Projects

 

Microbiome maintenance and inheritance         cropped-7266468174_ea337543d0_c.jpg

The human microbiome is considered crucial for human livelihood. As such, the transmission, inheritance, and maintenance of the human microbiome across generations must be the result of direct natural selection favoring the adaptations involved. Or is it? It’s possible that microbiome inheritance results incidentally from social interactions and other behaviours that have nothing to do with adaptations of microbiome transmission. It is also possible that the maintenance of a person’s microbiome results from behaviour meant to protect hosts from pathogenic microbes. The likelihood is that many causes are at play. An adaptationist research programme is the most productive philosophy to explore such questions. Through this approach researchers can discover not only the proximal mechanisms that underly microbiome inheritance and maintenance but also the deep-time historical causes of microbiome inheritance and maintenance through determination of the evolutionary origins and subsequent evolution of the features involved. The lab is at the earliest stages of exploring this line of research.

Key outputs: Fincher, Corey; Thornhill, Randy (2015): Are there adaptations for human microbiome inheritance and maintenance?  http://dx.doi.org/10.6084/m9.figshare.1539546. Presented at Exploring Human Host-Microbiome Interactions in Health and Disease 29 June – 1 July 2015, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.


Evolution of variable mate preferences

It’s hard to overstate the importance of mating and mating decisions for the evolution of life. We are interested in learning how evolution has shaped the mating-mind of humans and other species, and how this effects decisions today. Members of the lab have examined mate preferences for and the perception of facial characteristics.

New projects are focused on luteal sexual psychology and how values undergird mate preferences.

Key outputs: Wincenciak, J., Fincher, C. L., Fisher, C. I., Hahn, A. C., Jones, B. C., & DeBruine, L. M. (2015). Mate choice, mate preference, and biological markets: the relationship between partner choice and health preference is modulated by women’s own attractiveness. Evolution and Human Behavior.

Fisher, C. I., Fincher, C. L., Hahn, A. C., Little, A. C., DeBruine, L. M. & Jones, B. C. (2014). Do assortative preferences contribute to assortative mating for adiposity? British Journal of Psychology, 105, 474–485.

Jones, B. C., Feinberg, D. R., Watkins, C. D., Fincher, C. L., Little, A. C., & DeBruine, L. M. (2013). Pathogen disgust predicts women’s preferences for masculinity in men’s voices, faces, and bodies. Behavioral Ecology, 24, 373–379.

Jones, B. C., Fincher, C. L., Welling, L. L. M., Little, A. C., Feinber, D. R., Watkins, C. D., Al-Dujaili, E. A. S., DeBruine, L. M. (2013). Salivary cortisol and pathogen disgust predict men’s preferences for feminine shape cues in women’s faces. Biological Psychology, 92, 233–240.


Living with Infectious Diseases

Infectious diseases are killers, maimers and thieves. Often other people are the source. One way to avoid getting an infection is to avoid other people. But, that’s hardly a long-lasting fix because other people provide us with so much more than infections. Therein lies a perennial conundrum: how best to avoid infection but reap the benefits of social exchanges. Because this dilemma lies at the heart of all social exchanges, we have studied the effects of this problem on many aspects of social life such as governmental systems, warring behavior, religiosity, and cultural values.

Key outputs:

Thornhill, R., & Fincher, C. L. (2014) The Parasite-stress Theory of Values and Sociality: Infectious Disease, History and Human Values Worldwide. New York, NY: Springer.

Brown, G. D. A., Fincher, C. L., Walasek, L. (in press). Personality, parasites, attitudes and cooperation: a model of how infection prevalence influences ideology and social group formation. Topics in Cognitive Science.

Fincher, C. L., & Thornhill, R. (2012). Parasite-stress promotes in-group assortative sociality: the cases of strong family ties and heightened religiosity (target article). Behavioral and Brain Sciences, 35, 6179.

*Fincher, C. L., & Thornhill, R. (2012). The parasite-stress theory may be a general theory of culture and sociality (response article). Behavioral and Brain Sciences, 35, 99–119.

*This response article includes significant new empirical analyses not present in the target article.

Thornhill, R., Fincher, C. L., Murray, D. R., & Schaller, M. (2010). Zoonotic and non-zoonotic diseases in relation to human personality and societal values: support for the parasite-stress model. Evolutionary Psychology, 8, 151169.

Letendre, K., Fincher, C. L., & Thornhill, R. (2010). Does infectious disease cause global variation in the frequency of intrastate armed conflict and civil war? Biological Reviews, 85, 669–683.

Thornhill, R., Fincher, C. L., & Aran, D. (2009). Parasites, democratization and the liberalization of values across contemporary countries. Biological Reviews, 84, 113–131.

Fincher, C. L., Thornhill, R., Murray, D. R., & Schaller, M. (2008). Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism. Proceedings of the Royal Society B, 275, 1279–1285.


Infectious diseases also have large consequences for the evolutionary ecology of living. We have explored the consequences of this for lifespan and senescence and cognitive ability and mental health.

Key outputs:

Fox, M., Knapp, L. A., Andrews, P. W., & Fincher, C. L. (2013). Hygiene and the world distribution of Alzheimer’s disease: Epidemiological evidence for a relationship between microbial environment and age-adjusted disease burden. Evolution, Medicine, and Public Health, 2013, 173–186.

Eppig, C., Fincher, C. L., & Thornhill, R. (2011). Parasite prevalence and the distribution of intelligence among the states of the USA. Intelligence, 39, 155–160.

Eppig, C., Fincher, C. L., & Thornhill, R. (2010). Parasite prevalence and the worldwide distribution of cognitive ability. Proceedings of the Royal Society B, 277, 3801–3808.

Møller, A. P., Fincher, C. L., & Thornhill, R. (2009). Why men have shorter lives than women: Effects of resource availability, infectious disease and senescence. American Journal of Human Biology, 21, 357–364.


Avoiding and managing infections once they occur is the job of the immune system. We have contributed to the discussion on behavioural immunology.

Key outputs:

Thornhill, R., & Fincher, C. L. (2015) The parasite-stress theory of sociality and the behavioral immune system. In Evolutionary Perspectives in Social Psychology, L. Welling, V. Zeigler-Hill and T.K. Shackelford, Eds. New York, NY: Springer.

Thornhill, R., & Fincher, C. L. (2014) The Parasite-stress Theory of Values and Sociality: Infectious Disease, History and Human Values Worldwide. New York, NY: Springer.

Thornhill, R, & Fincher, C. L. (2014) The parasite-stress theory of sociality, the behavioral immune system, and human social and cognitive uniqueness. Evolutionary Behavioral Sciences, 8, 257–264.


Speciation and biodiversification

One of the solutions for avoiding infection is to avoid others that may carry infectious diseases that you have no defense against. A consequence of this action is a boundary against information flow (genes or cultural items). We have developed this idea into a models of biodiversification, applying it to cultures and species.

Key outputs:

Thornhill, R., & Fincher, C. L. (2013). The parasite-driven-wedge model of parapatric speciation. Journal of Zoology, 291, 23–33.

Fincher, C. L., & Thornhill, R. (2008). A parasite-driven wedge: infectious diseases may explain language and other biodiveristy. Oikos, 117, 1289–1297.

Fincher, C. L., & Thornhill, R. (2008). Assortative sociality, limited dispersal, infectious disease and the genesis of the global pattern of religion diversity. Proceedings of the Royal Society B, 275, 2587–2594.


Methods

It’s common for scientists to approach the same phenomena with different research questions and different tools. We have wrestled particularly with the problem of studying cultures from an evolutionary perspective. An outgrowth of this challenge was a portrayal of our thinking on important questions to ask and how some research questions (that of evolutionary origin versus maintenance) should not be conflated.

Key outputs:

Thornhill, R., & Fincher, C. L. (2013). The comparative method in cross-cultural and cross-species research. Evolutionary Biology, 40, 480–493.