The effect of species on perceptions of animals: predictors and causes of pet speciesism

What was Investigated and WhyDogs and pigs share multiple traits, yet dogs are typically companions whilst pigs are food, a phenomenon termed pet speciesism. Pet speciesism can harm animal welfare due to meat consumption and associated climate change. Whilst previous research evidences pet speciesism, research has yet to identify why pet speciesism occurs. This thesis therefore explores possible causes drawn from previous literature, so future interventions can reduce or prevent pet speciesism: behavioural self-relevance, subjective self-relevance, familiarity, similarity to humans, pet status, and profit status.How the Topic was InvestigatedPet speciesism is operationalised here across six psychological dimensions from the Stereotype Content Model (SCM) and Behaviours from Intergroup Affect and Stereotypes (BIAS) map: Warmth, competence, active help, active harm, passive help, and passive harm. I explored the above possible causes through six studies: Firstly, a regression identifying which variables were significantly associated with pet speciesism, followed by five experiments manipulating potential causes of pet speciesism.What was FoundBehavioural self-relevance, subjective self-relevance, familiarity, similarity, and pet status were significant regressors. The causal experiments found that: Neither behavioural nor subjective self-relevance caused pet speciesism. Conversely, similarity significantly caused pet speciesism in most SCM/BIAS map dimensions. Familiarity could not be effectively manipulated. Finally, pet status may significantly cause pet speciesism, but only in limited SCM/BIAS map dimensions.What Conclusions were DrawnThis thesis concludes that similarity causes pet speciesism in most SCM/BIAS map dimensions, whereas pet status may cause pet speciesism only in limited SCM/BIAS map dimensions. The thesis also highlights unexpected null effects of behavioural and subjective self-relevance and failed familiarity manipulations. Overall, this thesis uniquely tests extrinsic causes of pet speciesism, with extensive theoretical (demonstrating limitations of previous literature) and practical (informing interventions) implications. The research may inform interventions which decrease pet speciesism and reduce meat consumption.