The association between eating behaviour and moral views on animals from childhood to adulthood

How are moral judgements about animals related to whether people eat meat? We investigate the developmental trajectory of this question in German participants aged 8 to 74 years (N = 571, M = 24.84, SD = 14.52, female n = 394, male n = 177). Applying Bayesian modelling, we find no differences in moral judgements about animals and meat-eating when comparing children who eat and who do not eat meat. With increasing age, however, we observe differences between dietary groups: while omnivorous participants show increasing speciesist beliefs and evaluate meat-eating as morally acceptable, vegetarians' and vegans' moral judgements remain lower in speciesism and opposed to meat-eating across age. Early adolescence is highlighted as a crucial phase in which eating behaviour and moral judgements start to align. In line with recent theoretical models, we discuss the role of diet in developing speciesism and its implications for the uptake of sustainable diets.