University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 2016 INVESTIGATING EVALUATOR BIAS WHEN ASSESSING POTENTIAL PERFORMANCE HORSES WITH RESPECT TO HORSE COAT COLOUR Fisker Hansen, Anna http://hdl.handle.net/10026.1/5320 Plymouth University All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the author’s prior consent. 1 2 INVESTIGATING EVALUATOR BIAS WHEN ASSESSING POTENTIAL PERFORMANCE HORSES WITH RESPECT TO HORSE COAT COLOUR by ANNA FISKER HANSEN A thesis submitted to Plymouth University in partial fulfilment for the degree of Research Masters Equitation Science School of Biological Sciences Faculty of Science and Environment In collaboration with Duchy College January 2016 3 Abstract Investigating Evaluator Bias When Assessing Potential Performance Horses With Respect To Horse Coat Colour Anna Fisker Hansen Colour bias in judging has been suggested in a variety of subjectively judged sports, but has not previously been examined in equine performance evaluations. Potential performance evaluations, such as the British Breeding Futurity (BBF), can increase the momentary value of a horse, as status is given to horses with a premium evaluation record. The existence of bias in scoring could have economic implications particularly because the numbers of low value equids have increased in Britain, leading to worrying numbers of equine welfare cases. The potential occurrence of horse coat colour bias was investigated by 1) comparison of differences in BBF component and premium scores according to differently grouped horse colours (n=4001) using One-way ANOVA and Tukey HSD post hoc analysis, 2) analysis of the effect of different disciplines (dressage, eventing, show jumping and endurance), years (2008-2014) and regions on BBF scores according to horse colour, using permutation based analysis in PRIMER- E, 3) evaluation of the breed registrations of BBF horses and their genetic potential using the WBFSH top 100 stallion lists and 4) examination of British equestrians perception of horse colour bias using a questionnaire and subsequent analysis in SPSS (n=65). A significant difference in mean BBF scores was found between block coloured and spotted horses (and grey horses in dressage and eventing) compared to all other horse coat colours (p<0.05). The difference in scores between horse colours (R=0.094) was greater than the difference over time (R=0.082) and between regions (R=0.027). Grey/block coloured dressage evaluated horses (2014) had significantly lower scores than bay horses with a similar genetic potential (p=0.012). Spotted horses was the least favourite horse coat colour amongst survey participants (p=0.001) and also the colour thought to be least favoured by BBF evaluators. However, the majority of survey participants (55%) did not believe horse coat colour bias exists in the BBF. In conclusion, horse coat colour bias is suggested, proposed by the significantly lower scores of block coloured, spotted and, in part, grey horses in the BBF. This is attributed to the high visibility and possible motion camouflaging nature of these colours in addition to a historic negative bias amongst British equestrians. Keywords: Judging bias, colour bias, equine coat colour, sports horse breeding, young horse evaluation, British Breeding Futurity, British equestrians. 4 Table of Contents Abstract ............................................................................................................... 4 List of Tables....................................................................................................... 8 List of Figures ..................................................................................................... 9 Abbreviations .................................................................................................... 11 Acknowledgements ........................................................................................... 12 Author’s Declaration .......................................................................................... 13 Chapter 1: Introduction and Literature Review ............................................ 15 1.1 Aims and Objectives ............................................................................ 16 1.2 Equine Domestication and Coat Colour Selection ............................... 17 1.2.1 Pre-Domestication ......................................................................... 17 1.2.2 Post-Domestication ....................................................................... 20 1.2.3 Modern Day ................................................................................... 23 1.3 British Sport Horse Breeding ............................................................... 27 1.3.1 The British Breeding Futurity ......................................................... 28 1.4 Judging Bias ........................................................................................ 32 1.4.1 Judging Bias in Sport .................................................................... 33 1.4.2 Colour Bias in Sporting Events ...................................................... 36 1.4.3 Colour and Memory ....................................................................... 38 1.4.4 Equine Coat Colour Bias ............................................................... 39 1.5 Conclusion ........................................................................................... 41 Chapter 2: Investigating Horse Coat Colour Bias in the British Breeding Futurity ............................................................................................................ 42 2.1 Method ................................................................................................. 42 2.1.1 Data Collection .............................................................................. 42 2.1.2 Initial Data Handling ...................................................................... 44 2.1.3 Statistical Analysis ......................................................................... 47 2.2 Results ................................................................................................. 50 2.2.1 Effect of Horse Colour on BBF Premium Scores ........................... 50 2.2.2 Effect of Horse Colour on BBF Component Scores ...................... 66 2.2.3 Effect of Horse Colour, Year and Region on BBF Premium Scores........................................................................................................ 83 2.2.4 Effect of Horse Colour, Year and Region on BBF Premium Scores depending on Discipline ............................................................................. 88 2.3 Discussion and Conclusion .................................................................. 98 5 Chapter 3: Investigating Genetic (Bloodline) Contribution to Perceived Horse Coat Colour Bias ................................................................................ 100 3.1 Method ............................................................................................... 100 3.1.1 Initial Data Handling .................................................................... 101 3.1.2 Statistical Analysis ....................................................................... 103 3.2 Results ............................................................................................... 104 3.2.1 Horse Colour and Breed Register effect on BBF Premium Scores...................................................................................................... 104 3.2.2 Effect of Bloodline on BBF Scores .............................................. 108 3.2.3 Bloodline Quality Related to Horse Colour .................................. 117 3.3 Discussion and Conclusion ................................................................ 120 Chapter 4: Survey on the Perception of Horse Coat Colour Bias amongst British Equestrians ....................................................................................... 123 4.1 Method ............................................................................................... 123 4.1.1 Questionnaire Design .................................................................. 123 4.1.2 Sampling ..................................................................................... 131 4.1.3 Initial Data Handling .................................................................... 132 4.1.4 Statistical Analysis ....................................................................... 135 4.2 Results ............................................................................................... 136 4.2.1 Q1 Survey Participants’ Equestrian Experience .......................... 136 4.2.2 Q2 Survey Participants’ Favourite Horse Colour ......................... 137 4.2.3 Q3 Survey Participants’ Least Favourite Horse Colour ............... 138 4.2.4 Q4 Survey Participants’ Perception of Horse Colour