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Michael Lewis

Dr Michael Lewis


School of Psychology

+44 29208 75399
Tower Building, 70 Park Place, Cardiff, CF10 3AT
Media commentator
Available for postgraduate supervision


Research summary

Faces are highly important in human communication and interaction. My research explores various issues surrounding the psychology of seeing faces.

These issues include:

  • how we can distinguish between different faces so easily;
  • how we perceive emotional expressions;
  • how we detect faces are present in a scene;
  • what happens when face recognition goes wrong such as in Capgras delusion;
  • what makes faces attractive;
  • and also the effect of cosmetic therapies.





























Cyclic-shifts in female face preferences

Previous research has shown that women's preferences for male faces change on over the menstrual cycle. This has been shown with shifts in symmetry preference and masculinity preference. My research suggests that these finding could be an artifact of the methods commonly used in this kind of research.

Lewis, M. B. (2017). Fertility affects asymmetry detection not symmetry preference in assessments of 3D facial attractiveness. Cognition166, 130-138.

Lewis, M. B. (2020). Challenges to both reliability and validity of masculinity-preference measures in menstrual-cycle-effects research. Cognition197, 104201.

Mixed-race faces

Quite often, black faces can all look the same to white people and the reverse effect can be observed for white people. How do mixed-race faces fit within this? Mixed-race faces offer interesting ways to look at how race is categorised by facial appearance. Further, genetic processes, such as hybrid vigour, have also been suggested to affect mixed-race faces making them appear more attractive.

Lewis, M.B. (2010). Why are mixed-race people perceived as more attractive? Perception, 69, 136 – 138.

Lewis, M. B. (2016). Arguing that black is white: racial categorization of mixed-race faces. Perception45(5), 505-514.

Lewis, M. B. (2011). Who is the fairest of them all? Race, attractiveness and skin color sexual dimorphism. Personality and Individual Differences50(2), 159-162.

Botox and mood

Smiling makes us feel happy whereas frowning makes us feel sad. People who have undergone chemical denervation of their frown muscles (as in the treatment known as Botox) cannot frown. We have found that these people (possibly because they can no longer get the feedback from frowning) are happier than people for have had other forms of cosmetic treatment. Current research is exploring other possible psychological implications of these increasingly common cosmetic treatments.

Lewis, M.B. and Bowler, P.J. (2009). Botulinum toxin cosmetic therapy correlates with a more positive mood. Journal of Cosmetic Dermatology. 8, 24-26.

Lewis, M. B. (2018). The interactions between botulinum-toxin-based facial treatments and embodied emotions. Scientific reports8(1), 1-10.

Bias in face processing

Bias is observed in face processing such that unfamiliar race faces are processed differently to familiar race faces. This is also observed for faces of ages or genders different to the observer. My research has aimed to understand these biases in face processing.

Lewis, M. B., & Hills, P. J. (2018). Perceived race affects configural processing but not holistic processing in the composite-face task. Frontiers in psychology9, 1456.

Hills, P. J., & Lewis, M. B. (2011). The own-age face recognition bias in children and adults. Quarterly Journal of Experimental Psychology64(1), 17-23.

Hills, P. J., & Lewis, M. B. (2006). Reducing the own-race bias in face recognition by shifting attention. Quarterly Journal of Experimental Psychology59(6), 996-1002.

Hills, P. J., & Lewis, M. B. (2018). The development of face expertise: Evidence for a qualitative change in processing. Cognitive Development48, 1-18.

Hills, P. J., Ross, D. A., & Lewis, M. B. (2011). Attention misplaced: the role of diagnostic features in the face-inversion effect. Journal of Experimental Psychology: Human Perception and Performance37(5), 1396.

Navon effects

Reading the small letters of a large figure made out of small letters (a Navon figure) has unexpected effects. It makes people worse in face recognition tasks but it also makes wine recognition difficult.

My research tries to understand and apply these phenomena. For example, the same processes that cause this Navon effect might also explain why people are bad at recognising faces after they have been doing cryptic crosswords.

Lewis, M.B., Seeley, J. and Miles, C. (2009). Processing Navon letters can make wine taste different. Perception, 38, 1341-1346.

Lewis, M.B., Mills, C., Hills, P.J. and Weston, N. (2009). Navon letters affect face learning and face retrieval. Experimental Psychology, 56, 258-264.

Lewis, M.B. (2006). Last but not least: Eye-witnesses should not do cryptic crosswords prior to identity parades. Perception, 35, 1433-1436.

How can we spot a liar?

When people lie, do they first need to suppress the truth? If they do then can we use the additional time taken to do this to work out is someone is lying? Current research is looking at whether it takes longer to lie than to tell the truth. We are also exploring whether some people are particularly good at uncovering lies and trying to identify what cues they use.

Williams, E. J., Bott, L. A., Patrick, J., & Lewis, M. B. (2013). Telling lies: the irrepressible truth?. PLoS One8(4), e60713.

Face detection

While much is known about factors that affect face recognition, relatively little is know about face detection – that is the ability to spot a face in a scene. This is surprising as it is a pre-requisite of recognition in the natural world. Modern technological devices (eg cameras) often come with face detection software but these are often fooled in ways that a human observer would not be. My research in this area represents the first systematic analysis of the psychological processes of face detection.

Lewis, M.B. & Edmonds, A. J. (2005). Searching for faces in scrambled scenes. Visual Cognition, 12, 1309-1336.

Lewis, M.B. & Edmonds, A.J. (2003). Face detection: Mapping human performance, Perception. 32, 903-920.

Bindemann, M., & Lewis, M. B. (2013). Face detection differs from categorization: Evidence from visual search in natural scenes. Psychonomic bulletin & review20(6), 1140-1145.

Statistical methods in psycholinguistics

The word ‘cat’ is read faster than ‘aardvark’ but is this difference because it is shorter, more frequent, learnt at an earlier age, has more similar words or just more furry? This is a question that has taxed psycholinguists for time without resolution. The problem with this field of research is that experimental research (that is where, for example, the length of the word ‘cat’ is manipulated) is impossible. My research aimed to address this issue using structural equation modelling – a method that tests hypothetical causative relationships between a variety of observational variables just as you might use to see whether socioeconomic status or race predicts performance in school.

Lewis, M.B. and Vladeanu, M. (2006). What do we know about psycholinguistic effects? Quarterly Journal of Experimental Psychology, 59, 977-986.

Lewis, M.B. (2006). Chasing psycholinguistic effects: A cautionary tale. Visual Cognition, 13, 1012-1026.

Models of face recognition

We recognise faces very quickly, but the difference in the time taken to recognise some faces allow us to generate models of how the information is stored. Typical (or average) faces are recognised more slowly than distinctive faces. A caricatured face can be recognised faster than an accurate image of a person. Faces of races that we are unfamiliar with are slower to be recognised. I developed and tested a model of face memory (called face-space-r) which was based on a few simple principles but could explain a wide range of patterns in how we recognise faces.

Lewis, M.B. (2004). Face-Space-R: Towards a unified account of face recognition. Visual Cognition, 11, 29-69.

Valentine, T., Lewis, M. B., & Hills, P. J. (2016). Face-space: A unifying concept in face recognition research. Quarterly Journal of Experimental Psychology69(10), 1996-2019.


I am course directior of the MSc Psychology (Conversion) course and module co-ordinator the research design and statistics module on that course.

I teach research methods at Level 1 covering issues related to experimental design.

I run a level 2 practical on facial feedback supporting PS2007.

I supervise a wide range of final year projects many relating to the psychology of the face.


Undergraduate education

  • BSc First Class Hons in Mathematics and Psychology from The University of   Birmingham awarded in 1993.

Postgraduate education

  • My PhD was conducted in Cardiff University supervised by Robert Johnston and Hadyn Ellis. The thesis discussed and evaluated various models of face memory using a mixture of empirical studies and computational modelling. The degree was awarded in 1998.

Professional memberships

  • British Psychological Society
  • Experimental Psychological Society.

Academic positions

  • Ocober 2011: promoted to Reader, Cardiff University
  • 1999-2011: Lecturer/Senior Lecturer at Cardiff University
  • 1997-1999 Research Fellow at Cardiff University. Working with Hadyn Ellis on Capgras delusion.

Committees and reviewing

  • Grant reviewing: BBSRC; ESRC; EPSRC; Leverhulme trust
  • Journal reviewing (30 different journals, including JEP:Applied, JEP:HPP, JEP:LMC and Psychological Science)
  • BPS Cognitive Section Annual Conference 2010 organiser.


  • external examiner for MSc course in University of Kent
  • PhD examining (eg Lancaster University).


Faces are all very similar, yet we can distinguish among a large number of known faces and extract a wealth of information from them with remarkable speed and accuracy. My research explores this amazing ability from detecting a face in a visual scene, through recognition of a person, to retrieval of information concerning that person. I am also interested in the perception of emotional expressions, attractiveness and racial differences. While some experiments involve studying the learning of faces, other experiments explore facial illusions, caricatures, facial morphing or other visual manipulation of faces. Application of our understanding of face-related processes are important for studying dysfunctions of face recognition (eg, prosopagnosia, Capgras delusion) as well as within the forensic field.

If you are interested in applying for a PhD, or for further information regarding my postgraduate research, please contact me directly, or submit a formal application.

Current supervision

Alexander Diel

Alexander Diel

Research student