School of Anthropology & Conservation

Excellence in diversity Global in reach

Dr Sarah Johns

Senior Lecturer in Evolutionary Anthropology

Evolutionary psychology and behavioural ecology; timing of life-history events; human reproduction.


profile image for Dr Sarah Johns

School Roles and Responsibilities

Programme Convenor for MSc Evolution and Human Behaviour

Academic Background

I received my doctorate from the University of Bristol after completing an MPhil in biological anthropology at Corpus Christi College, Cambridge and an undergraduate degree in anthropology at the University of Pennsylvania. I am a broadly trained anthropologist with research experience in palaeoarchaeology, human reproductive behaviour, and the evolutionary psychology of human reproductive decision making. My primary research interest is in the variation of the age at first birth in humans, specifically focusing on teenage mothers, and how public health policy and evolutionary theory can be integrated.

My PhD research, which was funded in part by the Gloucestershire Health Authority and the Department of Health, was an empirical investigation into whether teenage motherhood is the result of an evolved reproductive strategy that allows for variation in life-history event timings, as predicted by evolutionary anthropological theory. Specifically, I tested the hypothesis that having children at an earlier age may promote lineage survival when the environment is unstable and risky, and personal future is uncertain. In addition, I investigated a possible psychological mechanism linking environment and behaviour in this context. I believe research that links both function and mechanism is the future direction for evolutionary studies of human behaviour, and my research is pushing the boundaries of the field in this direction.

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Also view these in the Kent Academic Repository

Myers, S. and Johns, S. (2018). Postnatal depression is associated with detrimental life-long and multi-generational impacts on relationship quality. PeerJ [Online] 6:e4305. Available at:
Myers, S., Burger, O. and Johns, S. (2017). Reply to Hagen and Thornhill. Evolution, Medicine, & Public Health [Online] 2017:24-26. Available at:
Myers, S. and Johns, S. (2017). Male infants, risk, and postnatal depression: Evidence supporting the Trivers-Willard hypothesis in a contemporary low-fertility context. Unpublished.
Mahoney, P. et al. (2016). Deciduous enamel 3D microwear texture analysis as an indicator of childhood diet in medieval Canterbury, England. Journal of Archaeological Science [Online] 66:128-136. Available at:
Myers, S., Burger, O. and Johns, S. (2016). Postnatal depression and reproductive success in modern, low-fertility contexts. Evolution, Medicine, and Public Health [Online] 1:71-84. Available at:
Conference or workshop item
Myers, S. et al. (2016). Postnatal depression - Weighing the evolutionary evidence. in: 18th Annual Conference of the British Association for Biological Anthropology and Osteoarchaeology (BABAO).
Myers, S. and Johns, S. (2018). Male infants and birth complications are associated with increased incidence of postnatal depression. Social Science & Medicine [Online]. Available at:
Deter, C. et al. (2017). Chapter 6. Aspects of human osteology. in: Parker-Pearson, M., Richards, M. and Chamberlain, A. eds. The Beaker People: isotopes, mobility and diet in prehistoric Britain. Oxford: Oxbow.
Showing 8 of 32 total publications in KAR. [See all in KAR]


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Teaching Interests

Major: Evolutionary and Biological Anthropology, Evolutionary Psychology, Human Behavioural Ecology, Human Sexual Behaviour.

Minor: Palaeoanthropology, Quantitative Research Methods, History of Evolutionary Theory


Programmes Convened


Modules Convened

  • SE565: Sex, Evolution, and Human Nature
  • SE533: Project in Anthropological Science
  • SE855: Research Project (Evolution & Human Behaviour)
  • SE858: Advanced topics in Human Behaviour

My modules contribute to multiple undergraduate programmes, including the BSc in Anthropology, BSc in Biological Anthropology, BA in Social Anthropology, as well as the MSc in Evolution and Human Behaviour. I also contribute to:

  • SE302: Foundations of Human Culture
  • SE307: Thinkers and Theories
  • SE308: Skills for Anthropology and Conservation
  • SE567: Methods in Anthropological Science
  • SE570: Current issues in Evolutionary Anthropology
  • SE856: Advanced Topics in Evolutionary Anthropology

and supervise student research in:

  • SE533: Project in Anthropological Science
  • SE855: Research Project (Evolution & Human Behaviour)

In 2008 I was a joint recipient (with S. Legge, and N. Newton-Fisher) of a university teaching prize for my role in developing the BSc in Anthropology and BSc in Biological Anthropology programmes.

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I am committed to understanding human reproductive timing and evolved sexual behaviour. During my most recent research period I have amassed a large, detailed data-set - one of the most comprehensive of its kind from the UK. My research was the first to study adolescent pregnancy from an evolutionary perspective, and is yielding new and potentially groundbreaking results. I am in the process of preparing much of this material for publication and exploiting further the untapped potential in this data set. This work has policy implications, specifically for governmental teenage pregnancy strategy (collaborating with Thomas Dickins). I have also conducted research exploring female genital colouration and male mating preferences, relationships between smoking, risk behaviour and mating success (funded by Novartis UK), and primate long bone trauma.

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Francesca Whitehouse, The menstrual cycle and female-to-female interactions: Explored through olfactory, visual and verbal/auditory communication. MSc by research. (Completed 2010)

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Professional Service
Committee member Biosocial Society: An international academic society that explores human biological and social diversity (from 2010).

Committee member European Human Behaviour and Evolution Association (EHBEA): An interdisciplinary society that supports the activities of European researchers with an interest in evolutionary accounts of human cognition, behaviour and society (2005-2010).

Steering committee member University of Kent Darwin200 Committee. (2008-2009).

Member (peer nominated) Centre for Sociology, Anthropology and Politics (C-SAP), Anthropology reference group responsible for developing the teaching of anthropology in UK Higher Education (2003-2010).

Conference sessions organised: Charity, Philanthropy, and Volunteerism, ESRC funded Darwin’s Medicine Seminar series, University of Kent (2009); Human Ecology, The British Association for Biological Anthropology and Osteoarchaeology. University of Bristol (2004)

Conference session chair: European Human Behaviour and Evolution Association annual meeting (2009), British Society for Population Studies Annual Meeting (2005); Human Behavior and Evolution Society Annual Meeting (2004).

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I am keen to promote public understanding of evolutionary theory, particularly how it relates to human behaviour. My work has received widespread press coverage and I am available to provide topical comment or in-depth discussion of topics related to human evolution & behaviour, evolutionary psychology, human sexuality, and teenage pregnancy.

Articles about my research and to which I have contributed have been published in: 


New Scientist: Die young, live fast: The evolution of an underclass. 7/17/2010, Vol. 207 Issue 2769, p02 [Feature-story about my research; this article was also the subject of that issue's editorial.]
I've also had work published in: The Guardian, The Daily Mail, The Sydney Morning Herald (Australia), The Age (Australia), Hindustan Times, The Times of India (India), The Scotsman, The Times, Pravda (Russia), L’Express (France), The National Post (Canada), Kent Messenger Group, Health Magazine (USA), Fit Pregnancy Magazine (USA), Eve Magazine (UK), Pregnancy and Birth Magazine (UK), Stylist Magazine (UK)

Online:,,, Nature Online, Yahoo news, MSN news. Science Daily, Live Science

TV & Radio:

Radio interviews to the 'Today Programme' (BBC Radio 4), Radio 5 Live, Radio New Zealand, BBC Gloucester, BBC Swindon, BBC Kent, Radio Dublin, and Radio Australia, ABC America TV Show “The Revolution”. Television Interviews for BBC3 documentary (Zig Zag productions). Programme pitch (Ricochet TV). 

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School of Anthropology and Conservation, Marlowe Building, The University of Kent, Canterbury, Kent, CT2 7NR, T: +44 (0)1227 827056

Last Updated: 25/01/2018