Is there a relationship between strength and direction of handedness and valenced side preference? (Testing the Body Specificity hypothesis)

Student thesis: Masters ThesisMasters by Research


This thesis tested the Body Specificity Hypothesis in left-handers and right-handers across two experimental studies. A novel approach to measuring handedness using a valid instrument (the EHI) and in more depth was used than in previous research (e.g., Casasanto, 2009; Casasanto & Henetz, 2012). Two combined EHI’s allowed for optimal, detailed handedness measures and classification of handedness. There were two main studies, Study 1 measured participants’ body specific responses to two sets of stimuli with positive and
negative qualities. Study 2 explored implicit attitudes of left-handers and right-handers, using a laterality-related Implicit associations test (IAT). The second task of Study 1 showed that all groups of left-handers were significantly more likely to select the left side as good. 

Consistent left-handers had the strongest left bias suggesting that strength of handedness might contribute to this finding. A significant left bias in Study 1, task 2 involved aspects of emotion, a smiley face and sad face. A similar result was found in the third task which included positive and negative labels; all handedness groups except strong right-handers showed a left bias (choosing the left side as more favourable). Some findings were inconclusive, but the body specificity hypothesis was supported in many aspects for lefthanders and was mainly found in emotionally salient situations. The initial findings of the
IAT in study 2 were that right-hander’s performance was better for compatible condition and left in incompatible but there were limitation and these will be discussed. The effects were strong in some cases for left-handers, suggesting that their handedness has an effect on their identity and that more consistent left-handers may have stronger side preferences.

This thesis also showed that there were differences in the way left-handers and righthanders see the world. Left-handers as a minority still face some aspects of discrimination in the sense of lack of left-orientated items, however, research, education and rising awareness of ‘what it is like to be a left-hander’ has significantly impacted on changing negative attitudes towards left-handers, which may be seen in growing resources and supportive groups for left-handers.
Date of AwardOct 2022
Original languageEnglish
Awarding Institution
  • Abertay University
SupervisorLynn Wright (Supervisor) & Scott Hardie (Supervisor)


  • Handedness ( strength and direction)
  • Body specificity
  • Implicit association

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