Evolutionary Psychological Science

, Volume 4, Issue 2, pp 158–165 | Cite as

Arching the Back (Lumbar Curvature) as a Female Sexual Proceptivity Signal: an Eye-Tracking Study

  • Farid PazhoohiEmail author
  • James F. Doyle
  • Antonio F. Macedo
  • Joana Arantes
Research Article


It is common in studies of human mate preference to have participants judge the attractiveness of photographs in which models adopt a neutral facial expression or a neutral body posture. However, it is unlikely that humans adopt neutral expressions and postures in normal social circumstances. One way in which posture can vary is in the curvature of the lower spine. In some non-human animals, a “lordotic” posture (in which the lower spine is curved towards the belly) is associated in females with readiness to mate. In humans, this posture may serve a similar function, attracting heterosexual men. In this study, participants were presented with computer-generated images of female bodies in which the back curvature was systematically manipulated. The result showed that small changes in lumbar curvature are associated with changes in the perception of attractiveness. Specifically, the result showed that there is a relationship between the range of the back curvatures used in this study and attractiveness, such that increasing the curvature increased the perception of attractiveness. Additionally, as the curvature increased, participants looked longer and fixated more on the hip region of the female bodies. This paper argues that the attractiveness of women in lordotic posture is due to a conserved mechanism across the taxa which signals proceptivity to men.


Lumbar curvature Lordosis Proceptive behavior Receptivity Sexual behavior Eye-tracking 



This study was conducted at the Psychology Research Centre (UID/PSI/01662/2013), University of Minho.

Funding Information

This study was supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). FP receives funding from FCT Portugal through grant SFRH/BD/114366/2016; AM receives funding from FCT Portugal through grants PTDC/DTP-EPI/0412/2012 and PEST-C/FIS/UI607/2011; JA receives funding from FCT Portugal through grant IF/01298/2014.

Compliance with Ethical Standards

Each participant gave written informed consent. The experiment was approved and conducted in accordance with ethical committee guidelines.

Conflict of Interests

The authors declare that they have no conflict of interest.


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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Farid Pazhoohi
    • 1
    Email author
  • James F. Doyle
    • 2
  • Antonio F. Macedo
    • 3
    • 4
  • Joana Arantes
    • 1
  1. 1.Department of Basic Psychology, School of PsychologyUniversity of MinhoBragaPortugal
  2. 2.StillwaterUSA
  3. 3.Vision Rehabilitation Laboratory, Department and Centre of PhysicsUniversity of MinhoBragaPortugal
  4. 4.Department of Medicine and OptometryLinnaeus UniversityKalmarSweden

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